diff --git a/src/acs/call-funcs.cpp b/src/acs/call-funcs.cpp
index d06fb555b..eb1193155 100644
--- a/src/acs/call-funcs.cpp
+++ b/src/acs/call-funcs.cpp
@@ -660,7 +660,7 @@ bool CallFunc_ThingCount(ACSVM::Thread *thread, const ACSVM::Word *argV, ACSVM::
 
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			{
 				continue;
 			}
diff --git a/src/d_clisrv.c b/src/d_clisrv.c
index cd2123507..6efd6e9b5 100644
--- a/src/d_clisrv.c
+++ b/src/d_clisrv.c
@@ -5363,7 +5363,7 @@ static INT16 Consistancy(void)
 	{
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 				continue;
 
 			mo = (mobj_t *)th;
diff --git a/src/d_netcmd.c b/src/d_netcmd.c
index 8320d9b49..00a5c4aa0 100644
--- a/src/d_netcmd.c
+++ b/src/d_netcmd.c
@@ -6462,7 +6462,7 @@ static void Command_Archivetest_f(void)
 	// assign mobjnum
 	i = 1;
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
-		if (th->function.acp1 != (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function != (actionf_p1)P_RemoveThinkerDelayed)
 			((mobj_t *)th)->mobjnum = i++;
 
 	// allocate buffer
diff --git a/src/d_think.h b/src/d_think.h
index 42dca1965..181745dd9 100644
--- a/src/d_think.h
+++ b/src/d_think.h
@@ -28,18 +28,11 @@ extern "C" {
 // To compile this as "ANSI C with classes" we will need to handle the various
 //  action functions cleanly.
 //
-typedef void (*actionf_v)();
 typedef void (*actionf_p1)(void *);
 
-typedef union
-{
-	actionf_v acv;
-	actionf_p1 acp1;
-} actionf_t;
-
 // Historically, "think_t" is yet another function pointer to a routine
 // to handle an actor.
-typedef actionf_t think_t;
+typedef actionf_p1 think_t;
 
 // Doubly linked list of actors.
 struct thinker_t
diff --git a/src/deh_lua.c b/src/deh_lua.c
index 5b00d1e2a..9200caf1f 100644
--- a/src/deh_lua.c
+++ b/src/deh_lua.c
@@ -75,14 +75,14 @@ static inline int lib_freeslot(lua_State *L)
 // Arguments: mobj_t actor, int var1, int var2
 static int action_call(lua_State *L)
 {
-	//actionf_t *action = lua_touserdata(L,lua_upvalueindex(1));
-	actionf_t *action = *((actionf_t **)luaL_checkudata(L, 1, META_ACTION));
+	//actionf_p1 *action = lua_touserdata(L,lua_upvalueindex(1));
+	actionf_p1 *action = *((actionf_p1 **)luaL_checkudata(L, 1, META_ACTION));
 	mobj_t *actor = *((mobj_t **)luaL_checkudata(L, 2, META_MOBJ));
 	var1 = (INT32)luaL_optinteger(L, 3, 0);
 	var2 = (INT32)luaL_optinteger(L, 4, 0);
 	if (!actor)
 		return LUA_ErrInvalid(L, "mobj_t");
-	action->acp1(actor);
+	(*action)(actor);
 	return 0;
 }
 
@@ -520,7 +520,7 @@ static inline int lib_getenum(lua_State *L)
 		// Retrieving them from this metatable allows them to be case-insensitive!
 		for (i = 0; actionpointers[i].name; i++)
 			if (fasticmp(word, actionpointers[i].name)) {
-				// We push the actionf_t* itself as userdata!
+				// We push the actionf_p1* itself as userdata!
 				LUA_PushUserdata(L, &actionpointers[i].action, META_ACTION);
 				return 1;
 			}
@@ -589,7 +589,7 @@ static int lib_getActionName(lua_State *L)
 {
 	if (lua_isuserdata(L, 1)) // arg 1 is built-in action, expect action userdata
 	{
-		actionf_t *action = *((actionf_t **)luaL_checkudata(L, 1, META_ACTION));
+		actionf_p1 *action = *((actionf_p1 **)luaL_checkudata(L, 1, META_ACTION));
 		const char *name = NULL;
 		if (!action)
 			return luaL_error(L, "not a valid action?");
@@ -651,11 +651,11 @@ int LUA_SOCLib(lua_State *L)
 
 const char *LUA_GetActionName(void *action)
 {
-	actionf_t *act = (actionf_t *)action;
+	actionf_p1 *act = (actionf_p1 *)action;
 	size_t z;
 	for (z = 0; actionpointers[z].name; z++)
 	{
-		if (actionpointers[z].action.acv == act->acv)
+		if (actionpointers[z].action == *act)
 			return actionpointers[z].name;
 	}
 	return NULL;
@@ -670,8 +670,6 @@ void LUA_SetActionByName(void *state, const char *actiontocompare)
 		if (fasticmp(actiontocompare, actionpointers[z].name))
 		{
 			st->action = actionpointers[z].action;
-			st->action.acv = actionpointers[z].action.acv; // assign
-			st->action.acp1 = actionpointers[z].action.acp1;
 			return;
 		}
 	}
diff --git a/src/deh_soc.c b/src/deh_soc.c
index 88f5675ed..f51d52eb7 100644
--- a/src/deh_soc.c
+++ b/src/deh_soc.c
@@ -2453,25 +2453,25 @@ void readframe(MYFILE *f, INT32 num)
 
 				for (z = 0; actionpointers[z].name; z++)
 				{
-					if (actionpointers[z].action.acv == states[num].action.acv)
+					if (actionpointers[z].action == states[num].action)
 						break;
 				}
 
 				z = 0;
 				found = LUA_SetLuaAction(&states[num], actiontocompare);
 				if (!found)
+				{
 					while (actionpointers[z].name)
 					{
 						if (fastcmp(actiontocompare, actionpointers[z].name))
 						{
 							states[num].action = actionpointers[z].action;
-							states[num].action.acv = actionpointers[z].action.acv; // assign
-							states[num].action.acp1 = actionpointers[z].action.acp1;
 							found = true;
 							break;
 						}
 						z++;
 					}
+				}
 
 				if (!found)
 					deh_warning("Unknown action %s", actiontocompare);
diff --git a/src/deh_tables.c b/src/deh_tables.c
index b2d807ade..bdee2e2b4 100644
--- a/src/deh_tables.c
+++ b/src/deh_tables.c
@@ -141,14 +141,14 @@ struct flickytypes_s FLICKYTYPES[] = {
 
 actionpointer_t actionpointers[] =
 {
-#define _(name, upper, ...) {{name}, "A_"#upper},
+#define _(name, upper, ...) {name, "A_"#upper},
 #include "info/actions.h"
 #undef _
 
-	{{NULL},                     "NONE"},
+	{NULL,                     "NONE"},
 
 	// This NULL entry must be the last in the list
-	{{NULL},                   NULL},
+	{NULL,                   NULL},
 };
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/src/deh_tables.h b/src/deh_tables.h
index 9a03ae68d..436eae71f 100644
--- a/src/deh_tables.h
+++ b/src/deh_tables.h
@@ -14,7 +14,7 @@
 #define __DEH_TABLES_H__
 
 #include "doomdef.h" // Constants
-#include "d_think.h" // actionf_t
+#include "d_think.h" // actionf_p1
 #include "info.h" // Mobj, state, sprite, etc constants
 #include "lua_script.h"
 #include "strbuf.h"
@@ -53,7 +53,7 @@ struct flickytypes_s {
   */
 struct actionpointer_t
 {
-	actionf_t action; ///< Function pointer corresponding to the actual action.
+	actionf_p1 action; ///< Function pointer corresponding to the actual action.
 	const char *name; ///< Name of the action in ALL CAPS.
 };
 
diff --git a/src/f_finale.c b/src/f_finale.c
index 350df9699..b6cf41e64 100644
--- a/src/f_finale.c
+++ b/src/f_finale.c
@@ -1619,7 +1619,7 @@ void F_TitleScreenTicker(boolean run)
 		{
 			for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 			{
-				if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+				if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 					continue;
 
 				mo2 = (mobj_t *)th;
diff --git a/src/g_demo.c b/src/g_demo.c
index 29a275507..561e8469e 100644
--- a/src/g_demo.c
+++ b/src/g_demo.c
@@ -1866,7 +1866,7 @@ void G_ConsGhostTic(INT32 playernum)
 				thinker_t *th = NULL;
 				for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 				{
-					if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+					if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 						continue;
 					mobj = (mobj_t *)th;
 					if (mobj->type == damage->type && mobj->x == damage->x && mobj->y == damage->y && mobj->z == damage->z)
@@ -4140,7 +4140,7 @@ void G_DoPlayMetal(void)
 	// find metal sonic
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo = (mobj_t *)th;
diff --git a/src/g_game.c b/src/g_game.c
index 23a1fbfcc..174dc8aeb 100644
--- a/src/g_game.c
+++ b/src/g_game.c
@@ -3439,7 +3439,7 @@ void G_ChangePlayerReferences(mobj_t *oldmo, mobj_t *newmo)
 	// scan all thinkers
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo2 = (mobj_t *)th;
diff --git a/src/hardware/hw_cache.c b/src/hardware/hw_cache.c
index bdf2f026b..b93e9c563 100644
--- a/src/hardware/hw_cache.c
+++ b/src/hardware/hw_cache.c
@@ -918,7 +918,7 @@ static void HWR_PrecacheLevelSprites(void)
 
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 != (actionf_p1)P_MobjThinker)
+		if (th->function != (actionf_p1)P_MobjThinker)
 			continue;
 
 		mo = (mobj_t *)th;
diff --git a/src/hardware/hw_light.c b/src/hardware/hw_light.c
index e66953b4f..e3e3e67e2 100644
--- a/src/hardware/hw_light.c
+++ b/src/hardware/hw_light.c
@@ -1412,7 +1412,7 @@ static void HWR_SearchLightsInMobjs(void)
 
 	// search in the list of thinkers
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
-		if (th->function.acp1 != (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function != (actionf_p1)P_RemoveThinkerDelayed)
 			HWR_AddMobjLights((mobj_t *)th);
 }
 #endif
diff --git a/src/info.h b/src/info.h
index 85cb1dd6d..fca10c158 100644
--- a/src/info.h
+++ b/src/info.h
@@ -36,7 +36,7 @@ enum actionnum {
 };
 
 // function prototypes for actions
-#define _(name, upper, ...) void name(mobj_t *actor);
+#define _(name, upper, ...) void name(void *thing);
 #include "info/actions.h"
 #undef _
 
@@ -84,7 +84,7 @@ struct state_t
 	spritenum_t sprite;
 	UINT32 frame; // we use the upper 16 bits for translucency and other shade effects
 	INT32 tics;
-	actionf_t action;
+	actionf_p1 action;
 	INT32 var1;
 	INT32 var2;
 	statenum_t nextstate;
diff --git a/src/k_battle.c b/src/k_battle.c
index e37cfee39..62bf544b5 100644
--- a/src/k_battle.c
+++ b/src/k_battle.c
@@ -374,7 +374,7 @@ void K_RunPaperItemSpawners(void)
 
 			for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 			{
-				if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+				if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 					continue;
 
 				mo = (mobj_t *)th;
@@ -537,7 +537,7 @@ void K_RespawnBattleBoxes(void)
 		mobj_t *box;
 		mobj_t *newmobj;
 
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		box = (mobj_t *)th;
diff --git a/src/k_kart.c b/src/k_kart.c
index bc7874537..d6ac28a47 100644
--- a/src/k_kart.c
+++ b/src/k_kart.c
@@ -11201,7 +11201,7 @@ boolean K_IsSPBInGame(void)
 	// spbplace is still -1 until a fired SPB finds a target, so look for an in-map SPB just in case
 	for (think = thlist[THINK_MOBJ].next; think != &thlist[THINK_MOBJ]; think = think->next)
 	{
-		if (think->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (think->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		if (((mobj_t *)think)->type == MT_SPB)
diff --git a/src/k_waypoint.cpp b/src/k_waypoint.cpp
index 8f9f72574..751aa427d 100644
--- a/src/k_waypoint.cpp
+++ b/src/k_waypoint.cpp
@@ -3056,7 +3056,7 @@ void K_AdjustWaypointsParameters (void)
 		th != &thlist[THINK_MOBJ];
 		th = th->next
 	){
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		anchor = (const mobj_t *)th;
diff --git a/src/lua_infolib.c b/src/lua_infolib.c
index 4cf0e413f..b830ab3b8 100644
--- a/src/lua_infolib.c
+++ b/src/lua_infolib.c
@@ -780,21 +780,19 @@ static int lib_setState(lua_State *L)
 			switch(lua_type(L, 3))
 			{
 			case LUA_TNIL: // Null? Set the action to nothing, then.
-				state->action.acp1 = NULL;
+				state->action = NULL;
 				break;
 			case LUA_TSTRING: // It's a string, expect the name of a built-in action
 				LUA_SetActionByName(state, lua_tostring(L, 3));
 				break;
 			case LUA_TUSERDATA: // It's a userdata, expect META_ACTION of a built-in action
 			{
-				actionf_t *action = *((actionf_t **)luaL_checkudata(L, 3, META_ACTION));
+				actionf_p1 *action = *((actionf_p1 **)luaL_checkudata(L, 3, META_ACTION));
 
 				if (!action)
 					return luaL_error(L, "not a valid action?");
 
 				state->action = *action;
-				state->action.acv = action->acv;
-				state->action.acp1 = action->acp1;
 				break;
 			}
 			case LUA_TFUNCTION: // It's a function (a Lua function or a C function? either way!)
@@ -804,7 +802,7 @@ static int lib_setState(lua_State *L)
 				lua_pushvalue(L, 3); // Bring it to the top of the stack
 				lua_rawset(L, -3); // Set it in the registry
 				lua_pop(L, 1); // pop LREG_STATEACTION
-				state->action.acp1 = (actionf_p1)A_Lua; // Set the action for the userdata.
+				state->action = (actionf_p1)A_Lua; // Set the action for the userdata.
 				break;
 			default: // ?!
 				return luaL_typerror(L, 3, "function");
@@ -862,7 +860,7 @@ boolean LUA_SetLuaAction(void *stv, const char *action)
 	lua_pop(gL, 1); // pop LREG_STATEACTION
 
 	lua_pop(gL, 2); // pop the function and LREG_ACTIONS
-	st->action.acp1 = (actionf_p1)A_Lua; // Set the action for the userdata.
+	st->action = (actionf_p1)A_Lua; // Set the action for the userdata.
 	return true; // action successfully set.
 }
 
@@ -929,9 +927,9 @@ static int state_get(lua_State *L)
 		number = st->tics;
 	else if (fastcmp(field,"action")) {
 		const char *name;
-		if (!st->action.acp1) // Action is NULL.
+		if (!st->action) // Action is NULL.
 			return 0; // return nil.
-		if (st->action.acp1 == (actionf_p1)A_Lua) { // This is a Lua function?
+		if (st->action == (actionf_p1)A_Lua) { // This is a Lua function?
 			lua_getfield(L, LUA_REGISTRYINDEX, LREG_STATEACTION);
 			I_Assert(lua_istable(L, -1));
 			lua_pushlightuserdata(L, st); // Push the state pointer and
@@ -948,9 +946,9 @@ static int state_get(lua_State *L)
 		return 1; // return just the function
 #ifdef DEVELOP
 	} else if (fastcmp(field,"actionname")) {
-		if (!st->action.acp1) { // Action is NULL.
+		if (!st->action) { // Action is NULL.
 			lua_pushstring(L, "NULL");
-		} else if (st->action.acp1 == (actionf_p1)A_Lua) { // This is a Lua function?
+		} else if (st->action == (actionf_p1)A_Lua) { // This is a Lua function?
 			lua_Debug ar;
 			lua_getfield(L, LUA_REGISTRYINDEX, LREG_STATEACTION);
 			I_Assert(lua_istable(L, -1));
@@ -1019,21 +1017,19 @@ static int state_set(lua_State *L)
 		switch(lua_type(L, 3))
 		{
 		case LUA_TNIL: // Null? Set the action to nothing, then.
-			st->action.acp1 = NULL;
+			st->action = NULL;
 			break;
 		case LUA_TSTRING: // It's a string, expect the name of a built-in action
 			LUA_SetActionByName(st, lua_tostring(L, 3));
 			break;
 		case LUA_TUSERDATA: // It's a userdata, expect META_ACTION of a built-in action
 		{
-			actionf_t *action = *((actionf_t **)luaL_checkudata(L, 3, META_ACTION));
+			actionf_p1 *action = *((actionf_p1 **)luaL_checkudata(L, 3, META_ACTION));
 
 			if (!action)
 				return luaL_error(L, "not a valid action?");
 
 			st->action = *action;
-			st->action.acv = action->acv;
-			st->action.acp1 = action->acp1;
 			break;
 		}
 		case LUA_TFUNCTION: // It's a function (a Lua function or a C function? either way!)
@@ -1043,7 +1039,7 @@ static int state_set(lua_State *L)
 			lua_pushvalue(L, 3); // Bring it to the top of the stack
 			lua_rawset(L, -3); // Set it in the registry
 			lua_pop(L, 1); // pop LREG_STATEACTION
-			st->action.acp1 = (actionf_p1)A_Lua; // Set the action for the userdata.
+			st->action = (actionf_p1)A_Lua; // Set the action for the userdata.
 			break;
 		default: // ?!
 			return luaL_typerror(L, 3, "function");
diff --git a/src/lua_libs.h b/src/lua_libs.h
index 7dbfbef38..bcde88696 100644
--- a/src/lua_libs.h
+++ b/src/lua_libs.h
@@ -96,7 +96,7 @@ extern lua_State *gL;
 #define META_COLORMAP "COLORMAP"
 #define META_CAMERA "CAMERA_T*"
 
-#define META_ACTION "ACTIONF_T*"
+#define META_ACTION "actionf_p1*"
 
 #define META_LUABANKS "LUABANKS[]*"
 
diff --git a/src/lua_script.c b/src/lua_script.c
index 387f6023f..393699177 100644
--- a/src/lua_script.c
+++ b/src/lua_script.c
@@ -1944,7 +1944,7 @@ void LUA_Sync(savebuffer_t *save, boolean network, boolean compat)
 			{
 				for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 				{
-					if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+					if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 						continue;
 
 					// archive function will determine when to skip mobjs,
@@ -1968,7 +1968,7 @@ void LUA_Sync(savebuffer_t *save, boolean network, boolean compat)
 				mobjnum = READUINT32(save->p); // read a mobjnum
 				for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 				{
-					if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+					if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 						continue;
 					if (((mobj_t *)th)->mobjnum != mobjnum) // find matching mobj
 						continue;
diff --git a/src/lua_thinkerlib.c b/src/lua_thinkerlib.c
index a51b62330..6404fa0df 100644
--- a/src/lua_thinkerlib.c
+++ b/src/lua_thinkerlib.c
@@ -44,7 +44,7 @@ static int iterationState_gc(lua_State *L)
 }
 
 #define push_thinker(th) {\
-	if ((th)->function.acp1 == (actionf_p1)P_MobjThinker) \
+	if ((th)->function == (actionf_p1)P_MobjThinker) \
 		LUA_PushUserdata(L, (th), META_MOBJ); \
 	else \
 		lua_pushlightuserdata(L, (th)); \
@@ -93,7 +93,7 @@ static int lib_iterateThinkers(lua_State *L)
 		return luaL_error(L, "next thinker invalidated during iteration");
 
 	for (; next != &thlist[THINK_MOBJ]; next = next->next)
-		if (!it->filter || next->function.acp1 == it->filter)
+		if (!it->filter || next->function == it->filter)
 		{
 			push_thinker(next);
 			if (next->next != &thlist[THINK_MOBJ])
diff --git a/src/m_cheat.c b/src/m_cheat.c
index a36e9ff1b..001d26832 100644
--- a/src/m_cheat.c
+++ b/src/m_cheat.c
@@ -440,7 +440,7 @@ void Command_ATeleport_f(void)
 
 			for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 			{
-				if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+				if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 					continue;
 
 				mo2 = (mobj_t *)th;
@@ -948,7 +948,7 @@ static mapthing_t *OP_CreateNewMapThing(player_t *player, UINT16 type, boolean c
 
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 				continue;
 
 			mo = (mobj_t *)th;
diff --git a/src/m_perfstats.c b/src/m_perfstats.c
index 93ae55800..489bbb4c6 100644
--- a/src/m_perfstats.c
+++ b/src/m_perfstats.c
@@ -438,7 +438,7 @@ static void M_DrawTickStats(void)
 			for (thinker = thlist[i].next; thinker != &thlist[i]; thinker = thinker->next)
 			{
 				thinkercount++;
-				if (thinker->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+				if (thinker->function == (actionf_p1)P_RemoveThinkerDelayed)
 					removecount++;
 				else if (i == THINK_POLYOBJ)
 					polythcount++;
@@ -446,7 +446,7 @@ static void M_DrawTickStats(void)
 					mainthcount++;
 				else if (i == THINK_MOBJ)
 				{
-					if (thinker->function.acp1 == (actionf_p1)P_MobjThinker)
+					if (thinker->function == (actionf_p1)P_MobjThinker)
 					{
 						mobj_t *mobj = (mobj_t*)thinker;
 						mobjcount++;
diff --git a/src/p_ceilng.c b/src/p_ceilng.c
index 8c6d01185..cebb160e2 100644
--- a/src/p_ceilng.c
+++ b/src/p_ceilng.c
@@ -323,7 +323,7 @@ INT32 EV_DoCeilingOLD(mtag_t tag, line_t *line, ceiling_e type)
 		ceiling = Z_Calloc(sizeof (*ceiling), PU_LEVSPEC, NULL);
 		P_AddThinker(THINK_MAIN, &ceiling->thinker);
 		sec->ceilingdata = ceiling;
-		ceiling->thinker.function.acp1 = (actionf_p1)T_MoveCeiling;
+		ceiling->thinker.function = (actionf_p1)T_MoveCeiling;
 		ceiling->sector = sec;
 		ceiling->crush = false;
 		ceiling->sourceline = (INT32)(line-lines);
@@ -465,7 +465,7 @@ static ceiling_t *CreateCeilingThinker(sector_t *sec)
 
 	sec->ceilingdata = ceiling;
 
-	ceiling->thinker.function.acp1 = (actionf_p1)T_MoveCeiling;
+	ceiling->thinker.function = (actionf_p1)T_MoveCeiling;
 	ceiling->sector = sec;
 	ceiling->crush = false;
 
@@ -799,7 +799,7 @@ INT32 EV_DoCrushOLD(mtag_t tag, line_t *line, ceiling_e type)
 		ceiling = Z_Calloc(sizeof (*ceiling), PU_LEVSPEC, NULL);
 		P_AddThinker(THINK_MAIN, &ceiling->thinker);
 		sec->ceilingdata = ceiling;
-		ceiling->thinker.function.acp1 = (actionf_p1)T_CrushCeiling;
+		ceiling->thinker.function = (actionf_p1)T_CrushCeiling;
 		ceiling->sector = sec;
 		ceiling->crush = true;
 		ceiling->sourceline = (INT32)(line-lines);
@@ -853,7 +853,7 @@ static ceiling_t *CreateCrushThinker(sector_t *sec)
 
 	sec->ceilingdata = ceiling;
 
-	ceiling->thinker.function.acp1 = (actionf_p1)T_MoveCeiling;
+	ceiling->thinker.function = (actionf_p1)T_MoveCeiling;
 	ceiling->sector = sec;
 	ceiling->crush = true;
 
diff --git a/src/p_enemy.c b/src/p_enemy.c
index 36ce44d69..a26f26467 100644
--- a/src/p_enemy.c
+++ b/src/p_enemy.c
@@ -35,7 +35,7 @@
 #include "hardware/hw3sound.h"
 #endif
 
-boolean LUA_CallAction(enum actionnum actionnum, mobj_t *actor);
+boolean LUA_CallAction(enum actionnum actionnum, void *actor);
 
 INT32 var1;
 INT32 var2;
@@ -565,8 +565,9 @@ void P_HomingAttack(mobj_t *source, mobj_t *enemy) // Home in on your target
 //		upper 16 bits = distance limit
 // var2 = If 1, only change to seestate. If 2, only play seesound. If 0, do both.
 //
-void A_Look(mobj_t *actor)
+void A_Look(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -601,8 +602,9 @@ void A_Look(mobj_t *actor)
 //		3 = don't check meleestate and missilestate
 // var2 = unused
 //
-void A_Chase(mobj_t *actor)
+void A_Chase(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 delta;
 	INT32 locvar1 = var1;
 
@@ -693,8 +695,9 @@ nomissile:
 // var1 = unused
 // var2 = unused
 //
-void A_FaceStabChase(mobj_t *actor)
+void A_FaceStabChase(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 delta;
 
 	if (LUA_CallAction(A_FACESTABCHASE, actor))
@@ -774,7 +777,7 @@ nomissile:
 		P_NewChaseDir(actor);
 }
 
-static void P_SharpDust(mobj_t *actor, mobjtype_t type, angle_t ang)
+static void P_SharpDust(void *actor, mobjtype_t type, angle_t ang)
 {
 	mobj_t *dust;
 
@@ -795,8 +798,9 @@ static void P_SharpDust(mobj_t *actor, mobjtype_t type, angle_t ang)
 // var1 = object to create
 // var2 = effective nextstate for created object
 //
-void A_StatueBurst(mobj_t *actor)
+void A_StatueBurst(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobjtype_t chunktype = (mobjtype_t)actor->info->raisestate;
@@ -850,8 +854,9 @@ void A_StatueBurst(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_JetJawRoam(mobj_t *actor)
+void A_JetJawRoam(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_JETJAWROAM, actor))
 		return;
 
@@ -877,8 +882,9 @@ void A_JetJawRoam(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_JetJawChomp(mobj_t *actor)
+void A_JetJawChomp(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 delta;
 
 	if (LUA_CallAction(A_JETJAWCHOMP, actor))
@@ -916,8 +922,9 @@ void A_JetJawChomp(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_PointyThink(mobj_t *actor)
+void A_PointyThink(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 i;
 	player_t *player = NULL;
 	mobj_t *ball;
@@ -1022,8 +1029,9 @@ void A_PointyThink(mobj_t *actor)
 //		1 = tracer
 // var2 = unused
 //
-void A_CheckBuddy(mobj_t *actor)
+void A_CheckBuddy(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 
 	if (LUA_CallAction(A_CHECKBUDDY, actor))
@@ -1042,8 +1050,9 @@ void A_CheckBuddy(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_HoodThink(mobj_t *actor)
+void A_HoodThink(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_HOODTHINK, actor))
 		return;
 
@@ -1099,8 +1108,9 @@ void A_HoodThink(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_ArrowCheck(mobj_t *actor)
+void A_ArrowCheck(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t x,y,z;
 	angle_t angle;
 	fixed_t dist;
@@ -1141,8 +1151,9 @@ void A_ArrowCheck(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_SnailerThink(mobj_t *actor)
+void A_SnailerThink(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_SNAILERTHINK, actor))
 		return;
 
@@ -1214,8 +1225,9 @@ void A_SnailerThink(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_SharpChase(mobj_t *actor)
+void A_SharpChase(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_SHARPCHASE, actor))
 		return;
 
@@ -1266,8 +1278,9 @@ void A_SharpChase(mobj_t *actor)
 // var1 = object # to spawn as dust (if not provided not done)
 // var2 = if nonzero, do the old-style spinning using this as the angle difference
 //
-void A_SharpSpin(mobj_t *actor)
+void A_SharpSpin(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	angle_t oldang = actor->angle;
@@ -1303,8 +1316,9 @@ void A_SharpSpin(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_SharpDecel(mobj_t *actor)
+void A_SharpDecel(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_SHARPDECEL, actor))
 		return;
 
@@ -1324,8 +1338,9 @@ void A_SharpDecel(mobj_t *actor)
 // var1 = speed (actor info's speed if 0)
 // var2 = state to switch to when blocked (spawnstate if 0)
 //
-void A_CrushstaceanWalk(mobj_t *actor)
+void A_CrushstaceanWalk(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = (var1 ? var1 : (INT32)actor->info->speed);
 	INT32 locvar2 = (var2 ? var2 : (INT32)actor->info->spawnstate);
 	angle_t ang = actor->angle + ((actor->flags2 & MF2_AMBUSH) ? ANGLE_90 : ANGLE_270);
@@ -1355,8 +1370,9 @@ void A_CrushstaceanWalk(mobj_t *actor)
 // var1 = unused
 // var2 = state to go to if unsuccessful (spawnstate if 0)
 //
-void A_CrushstaceanPunch(mobj_t *actor)
+void A_CrushstaceanPunch(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar2 = (var2 ? var2 : (INT32)actor->info->spawnstate);
 
 	if (LUA_CallAction(A_CRUSHSTACEANPUNCH, actor))
@@ -1384,8 +1400,9 @@ void A_CrushstaceanPunch(mobj_t *actor)
 // var1 = sideways offset
 // var2 = vertical offset
 //
-void A_CrushclawAim(mobj_t *actor)
+void A_CrushclawAim(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *crab = actor->tracer;
@@ -1446,8 +1463,9 @@ void A_CrushclawAim(mobj_t *actor)
 //		anything else - backwards
 // var2 = state to change to when done
 //
-void A_CrushclawLaunch(mobj_t *actor)
+void A_CrushclawLaunch(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *crab = actor->tracer;
@@ -1581,8 +1599,9 @@ void A_CrushclawLaunch(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_VultureVtol(mobj_t *actor)
+void A_VultureVtol(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_VULTUREVTOL, actor))
 		return;
 
@@ -1616,8 +1635,9 @@ void A_VultureVtol(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_VultureCheck(mobj_t *actor)
+void A_VultureCheck(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_VULTURECHECK, actor))
 		return;
 
@@ -1640,8 +1660,9 @@ void A_VultureCheck(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_SkimChase(mobj_t *actor)
+void A_SkimChase(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 delta;
 
 	if (LUA_CallAction(A_SKIMCHASE, actor))
@@ -1728,8 +1749,9 @@ nomissile:
 // var1 = unused
 // var2 = unused
 //
-void A_FaceTarget(mobj_t *actor)
+void A_FaceTarget(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_FACETARGET, actor))
 		return;
 
@@ -1746,8 +1768,9 @@ void A_FaceTarget(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_FaceTracer(mobj_t *actor)
+void A_FaceTracer(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_FACETRACER, actor))
 		return;
 
@@ -1766,8 +1789,9 @@ void A_FaceTracer(mobj_t *actor)
 //		var2 >> 16 = height offset
 //		var2 & 65535 = airtime
 //
-void A_LobShot(mobj_t *actor)
+void A_LobShot(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2 >> 16;
 	mobj_t *shot;
@@ -1866,8 +1890,9 @@ void A_LobShot(mobj_t *actor)
 // var1 = object # to shoot
 // var2 = height offset
 //
-void A_FireShot(mobj_t *actor)
+void A_FireShot(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t z;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
@@ -1903,8 +1928,9 @@ void A_FireShot(mobj_t *actor)
 // var1 = object # to shoot
 // var2 = height offset
 //
-void A_SuperFireShot(mobj_t *actor)
+void A_SuperFireShot(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t z;
 	mobj_t *mo;
 	INT32 locvar1 = var1;
@@ -1950,8 +1976,9 @@ void A_SuperFireShot(mobj_t *actor)
 //		4 - Boss 3 Right side upper
 //		5 - Boss 3 Right side lower
 //
-void A_BossFireShot(mobj_t *actor)
+void A_BossFireShot(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t x, y, z;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
@@ -2035,8 +2062,9 @@ void A_BossFireShot(mobj_t *actor)
 // var1 = object # to shoot
 // var2 = firing sound
 //
-void A_Boss7FireMissiles(mobj_t *actor)
+void A_Boss7FireMissiles(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t dummymo;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
@@ -2101,8 +2129,9 @@ void A_Boss7FireMissiles(mobj_t *actor)
 //		0 - Boss 1 Left side
 //		1 - Boss 1 Right side
 //
-void A_Boss1Laser(mobj_t *actor)
+void A_Boss1Laser(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t x, y, z, floorz, speed;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
@@ -2207,8 +2236,9 @@ void A_Boss1Laser(mobj_t *actor)
 //		1 - steady focus with fixed movement speed
 // var2 = unused
 //
-void A_FocusTarget(mobj_t *actor)
+void A_FocusTarget(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 
 	if (LUA_CallAction(A_FOCUSTARGET, actor))
@@ -2257,8 +2287,9 @@ void A_FocusTarget(mobj_t *actor)
 // var1 = sfx to play
 // var2 = sfx to play in pinch
 //
-void A_Boss4Reverse(mobj_t *actor)
+void A_Boss4Reverse(void *thing)
 {
+	mobj_t *actor = thing;
 	sfxenum_t locvar1 = (sfxenum_t)var1;
 	sfxenum_t locvar2 = (sfxenum_t)var2;
 
@@ -2293,8 +2324,9 @@ void A_Boss4Reverse(mobj_t *actor)
 // var1 = sfx to play
 // var2 = unused
 //
-void A_Boss4SpeedUp(mobj_t *actor)
+void A_Boss4SpeedUp(void *thing)
 {
+	mobj_t *actor = thing;
 	sfxenum_t locvar1 = (sfxenum_t)var1;
 
 	if (LUA_CallAction(A_BOSS4SPEEDUP, actor))
@@ -2311,8 +2343,9 @@ void A_Boss4SpeedUp(mobj_t *actor)
 // var1 = sfx to play
 // var2 = unused
 //
-void A_Boss4Raise(mobj_t *actor)
+void A_Boss4Raise(void *thing)
 {
+	mobj_t *actor = thing;
 	sfxenum_t locvar1 = (sfxenum_t)var1;
 
 	if (LUA_CallAction(A_BOSS4RAISE, actor))
@@ -2337,8 +2370,9 @@ void A_Boss4Raise(mobj_t *actor)
 //
 #define SKULLSPEED (20*FRACUNIT)
 
-void A_SkullAttack(mobj_t *actor)
+void A_SkullAttack(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *dest;
 	angle_t an;
 	INT32 dist;
@@ -2453,8 +2487,9 @@ void A_SkullAttack(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_BossZoom(mobj_t *actor)
+void A_BossZoom(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *dest;
 	angle_t an;
 	INT32 dist;
@@ -2490,8 +2525,9 @@ void A_BossZoom(mobj_t *actor)
 //		& 2 - Use entire vertical range of object to spawn
 // var2 = Object to spawn. Default is MT_SONIC3KBOSSEXPLODE.
 //
-void A_BossScream(mobj_t *actor)
+void A_BossScream(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *mo;
 	fixed_t x, y, z;
 	angle_t fa;
@@ -2542,8 +2578,9 @@ void A_BossScream(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_Scream(mobj_t *actor)
+void A_Scream(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_SCREAM, actor))
 		return;
 
@@ -2560,8 +2597,9 @@ void A_Scream(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_Pain(mobj_t *actor)
+void A_Pain(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_PAIN, actor))
 		return;
 
@@ -2579,8 +2617,9 @@ void A_Pain(mobj_t *actor)
 // var1 = value to set repeat to if nonzero
 // var2 = unused
 //
-void A_Fall(mobj_t *actor)
+void A_Fall(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 
 	if (LUA_CallAction(A_FALL, actor))
@@ -2606,8 +2645,9 @@ void A_Fall(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_MonitorPop(mobj_t *actor)
+void A_MonitorPop(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *remains;
 	mobjtype_t explode;
 	mobjtype_t item = 0;
@@ -2702,8 +2742,9 @@ void A_MonitorPop(mobj_t *actor)
 // var1 = damagetype
 // var2 = unused
 //
-void A_Explode(mobj_t *actor)
+void A_Explode(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 
 	if (LUA_CallAction(A_EXPLODE, actor))
@@ -2747,7 +2788,7 @@ static void P_DoBossVictory(mobj_t *mo)
 	// scan the remaining thinkers to see if all bosses are dead
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo2 = (mobj_t *)th;
@@ -2822,8 +2863,9 @@ static void P_DoBossDefaultDeath(mobj_t *mo)
 // var1 = unused
 // var2 = unused
 //
-void A_BossDeath(mobj_t *mo)
+void A_BossDeath(void *thing)
 {
+	mobj_t *mo = thing;
 	INT32 i;
 
 	if (LUA_CallAction(A_BOSSDEATH, mo))
@@ -2890,8 +2932,9 @@ void A_BossDeath(mobj_t *mo)
 // var1 = unused
 // var2 = unused
 //
-void A_RingBox(mobj_t *actor)
+void A_RingBox(void *thing)
 {
+	mobj_t *actor = thing;
 	player_t *player;
 
 	if (LUA_CallAction(A_RINGBOX, actor))
@@ -2917,8 +2960,9 @@ void A_RingBox(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_AwardScore(mobj_t *actor)
+void A_AwardScore(void *thing)
 {
+	mobj_t *actor = thing;
 	player_t *player;
 
 	if (LUA_CallAction(A_AWARDSCORE, actor))
@@ -2944,8 +2988,9 @@ void A_AwardScore(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_ScoreRise(mobj_t *actor)
+void A_ScoreRise(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_SCORERISE, actor))
 		return;
 
@@ -2960,8 +3005,9 @@ void A_ScoreRise(mobj_t *actor)
 // var1 = jump strength
 // var2 = horizontal movement
 //
-void A_BunnyHop(mobj_t *actor)
+void A_BunnyHop(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -2983,8 +3029,9 @@ void A_BunnyHop(mobj_t *actor)
 // var1 = Distance to look for players.  If no player is in this distance, bubbles aren't spawned. (Ambush overrides)
 // var2 = unused
 //
-void A_BubbleSpawn(mobj_t *actor)
+void A_BubbleSpawn(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 i, locvar1 = var1;
 	UINT8 prandom;
 	mobj_t *bubble = NULL;
@@ -3035,8 +3082,9 @@ void A_BubbleSpawn(mobj_t *actor)
 // var1 = Distance to look for players.  If no player is in this distance, bubbles aren't spawned. (Ambush overrides)
 // var2 = unused
 //
-void A_FanBubbleSpawn(mobj_t *actor)
+void A_FanBubbleSpawn(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 i, locvar1 = var1;
 	UINT8 prandom;
 	mobj_t *bubble = NULL;
@@ -3083,8 +3131,9 @@ void A_FanBubbleSpawn(mobj_t *actor)
 //		1 = Rise straight up
 // var2 = rising speed
 //
-void A_BubbleRise(mobj_t *actor)
+void A_BubbleRise(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -3122,8 +3171,9 @@ void A_BubbleRise(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_BubbleCheck(mobj_t *actor)
+void A_BubbleCheck(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_BUBBLECHECK, actor))
 		return;
 
@@ -3140,8 +3190,9 @@ void A_BubbleCheck(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_AttractChase(mobj_t *actor)
+void A_AttractChase(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_ATTRACTCHASE, actor))
 		return;
 
@@ -3366,8 +3417,9 @@ void A_AttractChase(mobj_t *actor)
 //		lower 16 bits = proximity check distance (0 disables)
 //		upper 16 bits = 0 to check proximity with target, 1 for tracer
 //
-void A_DropMine(mobj_t *actor)
+void A_DropMine(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	fixed_t z;
@@ -3416,8 +3468,9 @@ void A_DropMine(mobj_t *actor)
 // var1 = Jump strength (in FRACBITS), if specified. Otherwise, uses the angle value.
 // var2 = Trail object to spawn, if desired.
 //
-void A_FishJump(mobj_t *actor)
+void A_FishJump(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -3476,8 +3529,9 @@ void A_FishJump(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_SetSolidSteam(mobj_t *actor)
+void A_SetSolidSteam(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_SETSOLIDSTEAM, actor))
 		return;
 
@@ -3508,8 +3562,9 @@ void A_SetSolidSteam(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_UnsetSolidSteam(mobj_t *actor)
+void A_UnsetSolidSteam(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_UNSETSOLIDSTEAM, actor))
 		return;
 
@@ -3524,8 +3579,9 @@ void A_UnsetSolidSteam(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_SignPlayer(mobj_t *actor)
+void A_SignPlayer(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *ov;
 	if (LUA_CallAction(A_SIGNPLAYER, actor))
 		return;
@@ -3554,8 +3610,9 @@ void A_SignPlayer(mobj_t *actor)
 // var1 = unused
 // var2 = invert, z offset
 //
-void A_OverlayThink(mobj_t *actor)
+void A_OverlayThink(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t destx, desty;
 
 	if (LUA_CallAction(A_OVERLAYTHINK, actor))
@@ -3609,8 +3666,9 @@ void A_OverlayThink(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_JetChase(mobj_t *actor)
+void A_JetChase(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t thefloor;
 
 	if (LUA_CallAction(A_JETCHASE, actor))
@@ -3704,8 +3762,9 @@ void A_JetChase(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_JetbThink(mobj_t *actor)
+void A_JetbThink(void *thing)
 {
+	mobj_t *actor = thing;
 	sector_t *nextsector;
 	fixed_t thefloor;
 
@@ -3770,8 +3829,9 @@ void A_JetbThink(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_JetgShoot(mobj_t *actor)
+void A_JetgShoot(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t dist;
 
 	if (LUA_CallAction(A_JETGSHOOT, actor))
@@ -3810,8 +3870,9 @@ void A_JetgShoot(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_ShootBullet(mobj_t *actor)
+void A_ShootBullet(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t dist;
 
 	if (LUA_CallAction(A_SHOOTBULLET, actor))
@@ -3839,8 +3900,9 @@ void A_ShootBullet(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_MinusDigging(mobj_t *actor)
+void A_MinusDigging(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_MINUSDIGGING, actor))
 		return;
 
@@ -3890,9 +3952,9 @@ void A_MinusDigging(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_MinusPopup(mobj_t *actor)
+void A_MinusPopup(void *thing)
 {
-
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_MINUSPOPUP, actor))
 		return;
 
@@ -3912,8 +3974,9 @@ void A_MinusPopup(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_MinusCheck(mobj_t *actor)
+void A_MinusCheck(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_MINUSCHECK, actor))
 		return;
 
@@ -3939,8 +4002,9 @@ void A_MinusCheck(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_ChickenCheck(mobj_t *actor)
+void A_ChickenCheck(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_CHICKENCHECK, actor))
 		return;
 
@@ -3966,8 +4030,9 @@ void A_ChickenCheck(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_JetgThink(mobj_t *actor)
+void A_JetgThink(void *thing)
 {
+	mobj_t *actor = thing;
 	sector_t *nextsector;
 
 	fixed_t thefloor;
@@ -4020,8 +4085,9 @@ void A_JetgThink(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_MouseThink(mobj_t *actor)
+void A_MouseThink(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_MOUSETHINK, actor))
 		return;
 
@@ -4049,8 +4115,9 @@ void A_MouseThink(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_DetonChase(mobj_t *actor)
+void A_DetonChase(void *thing)
 {
+	mobj_t *actor = thing;
 	angle_t exact;
 	fixed_t xydist, dist;
 
@@ -4198,8 +4265,9 @@ void A_DetonChase(mobj_t *actor)
 //		upper 16 bits = forward/backward offset
 //		lower 16 bits = sideways offset
 //
-void A_CapeChase(mobj_t *actor)
+void A_CapeChase(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *chaser;
 	fixed_t foffsetx, foffsety, boffsetx, boffsety;
 	INT32 locvar1 = var1;
@@ -4261,8 +4329,9 @@ void A_CapeChase(mobj_t *actor)
 //		1 = Use tracer
 // var2 = unused
 //
-void A_RotateSpikeBall(mobj_t *actor)
+void A_RotateSpikeBall(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	const fixed_t radius = FixedMul(12*actor->info->speed, actor->scale);
 
@@ -4312,8 +4381,9 @@ void A_RotateSpikeBall(mobj_t *actor)
 //		2 = Throw when target leaves MF2_SKULLFLY.
 // var2 = unused
 //
-void A_UnidusBall(mobj_t *actor)
+void A_UnidusBall(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	boolean canthrow = false;
 
@@ -4405,8 +4475,9 @@ void A_UnidusBall(mobj_t *actor)
 //
 // var1 = unused
 // var2 = unused
-void A_RockSpawn(mobj_t *actor)
+void A_RockSpawn(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *mo;
 	mobjtype_t type;
 	fixed_t dist;
@@ -4449,8 +4520,9 @@ void A_RockSpawn(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_SlingAppear(mobj_t *actor)
+void A_SlingAppear(void *thing)
 {
+	mobj_t *actor = thing;
 	UINT8 mlength = 4;
 	mobj_t *spawnee, *hprev;
 
@@ -4499,8 +4571,9 @@ void A_SlingAppear(mobj_t *actor)
 //		lower 16 bits = if > 0, state to change to when fuse = 1
 //		upper 16 bits: 0 = (default) don't set fuse unless 0, 1 = force change, 2 = force no change
 //
-void A_SetFuse(mobj_t *actor)
+void A_SetFuse(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -4524,8 +4597,9 @@ void A_SetFuse(mobj_t *actor)
 // var1 = shoot bullets?
 // var2 = "pogo mode" speed
 //
-void A_CrawlaCommanderThink(mobj_t *actor)
+void A_CrawlaCommanderThink(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t dist;
 	sector_t *nextsector;
 	fixed_t thefloor;
@@ -4674,8 +4748,9 @@ void A_CrawlaCommanderThink(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_RingExplode(mobj_t *actor)
+void A_RingExplode(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *mo2;
 	thinker_t *th;
 	angle_t d;
@@ -4690,7 +4765,7 @@ void A_RingExplode(mobj_t *actor)
 
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo2 = (mobj_t *)th;
@@ -4718,7 +4793,9 @@ void A_RingExplode(mobj_t *actor)
 // var1 = object # to explode as debris
 // var2 = unused
 //
-void A_OldRingExplode(mobj_t *actor) {
+void A_OldRingExplode(void *thing)
+{
+	mobj_t *actor = thing;
 	UINT8 i;
 	mobj_t *mo;
 	const fixed_t ns = FixedMul(20 * FRACUNIT, actor->scale);
@@ -4796,8 +4873,9 @@ void A_OldRingExplode(mobj_t *actor) {
 // var1 = unused
 // var2 = unused
 //
-void A_MixUp(mobj_t *actor)
+void A_MixUp(void *thing)
 {
+	mobj_t *actor = thing;
 	boolean teleported[MAXPLAYERS];
 	INT32 i, numplayers = 0, prandom = 0;
 
@@ -5042,8 +5120,9 @@ void A_MixUp(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_Boss1Chase(mobj_t *actor)
+void A_Boss1Chase(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 delta;
 
 	if (LUA_CallAction(A_BOSS1CHASE, actor))
@@ -5160,8 +5239,9 @@ nomissile:
 // var1 = unused
 // var2 = unused
 //
-void A_Boss2Chase(mobj_t *actor)
+void A_Boss2Chase(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t radius;
 	boolean reverse = false;
 	INT32 speedvar;
@@ -5290,8 +5370,9 @@ void A_Boss2Chase(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_Boss2Pogo(mobj_t *actor)
+void A_Boss2Pogo(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_BOSS2POGO, actor))
 		return;
 
@@ -5336,8 +5417,9 @@ void A_Boss2Pogo(mobj_t *actor)
 // var1 = Invincibility duration
 // var2 = unused
 //
-void A_Boss2TakeDamage(mobj_t *actor)
+void A_Boss2TakeDamage(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 
 	if (LUA_CallAction(A_BOSS2TAKEDAMAGE, actor))
@@ -5358,8 +5440,9 @@ void A_Boss2TakeDamage(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_Boss7Chase(mobj_t *actor)
+void A_Boss7Chase(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 delta;
 	INT32 i;
 
@@ -5480,8 +5563,9 @@ void A_Boss7Chase(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_GoopSplat(mobj_t *actor)
+void A_GoopSplat(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_GOOPSPLAT, actor))
 		return;
 
@@ -5502,8 +5586,9 @@ void A_GoopSplat(mobj_t *actor)
 // var1 = pogo jump strength
 // var2 = idle pogo speed
 //
-void A_Boss2PogoSFX(mobj_t *actor)
+void A_Boss2PogoSFX(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -5544,8 +5629,9 @@ void A_Boss2PogoSFX(mobj_t *actor)
 // var1 = pogo jump strength
 // var2 = idle pogo speed
 //
-void A_Boss2PogoTarget(mobj_t *actor)
+void A_Boss2PogoTarget(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -5632,8 +5718,9 @@ void A_Boss2PogoTarget(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_EggmanBox(mobj_t *actor)
+void A_EggmanBox(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_EGGMANBOX, actor))
 		return;
 
@@ -5653,8 +5740,9 @@ void A_EggmanBox(mobj_t *actor)
 // var1 = object # to repeatedly fire
 // var2 = distance threshold
 //
-void A_TurretFire(mobj_t *actor)
+void A_TurretFire(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 count = 0;
 	fixed_t dist;
 	INT32 locvar1 = var1;
@@ -5691,8 +5779,9 @@ void A_TurretFire(mobj_t *actor)
 // var1 = object # to repeatedly fire
 // var2 = distance threshold
 //
-void A_SuperTurretFire(mobj_t *actor)
+void A_SuperTurretFire(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 count = 0;
 	fixed_t dist;
 	INT32 locvar1 = var1;
@@ -5730,8 +5819,9 @@ void A_SuperTurretFire(mobj_t *actor)
 // var1 = Don't play activesound?
 // var2 = unused
 //
-void A_TurretStop(mobj_t *actor)
+void A_TurretStop(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 
 	if (LUA_CallAction(A_TURRETSTOP, actor))
@@ -5751,8 +5841,9 @@ void A_TurretStop(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_SparkFollow(mobj_t *actor)
+void A_SparkFollow(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_SPARKFOLLOW, actor))
 		return;
 
@@ -5783,8 +5874,9 @@ void A_SparkFollow(mobj_t *actor)
 // var1 = sfx to play
 // var2 = length of sfx, set to threshold if played
 //
-void A_BuzzFly(mobj_t *actor)
+void A_BuzzFly(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -5883,8 +5975,9 @@ void A_BuzzFly(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_GuardChase(mobj_t *actor)
+void A_GuardChase(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 delta;
 
 	if (LUA_CallAction(A_GUARDCHASE, actor))
@@ -5939,10 +6032,10 @@ void A_GuardChase(mobj_t *actor)
 	// Now that we've moved, its time for our shield to move!
 	// Otherwise it'll never act as a proper overlay.
 	if (actor->tracer && actor->tracer->state
-	&& actor->tracer->state->action.acp1)
+	&& actor->tracer->state->action)
 	{
 		var1 = actor->tracer->state->var1, var2 = actor->tracer->state->var2;
-		actor->tracer->state->action.acp1(actor->tracer);
+		actor->tracer->state->action(actor->tracer);
 	}
 }
 
@@ -5953,8 +6046,9 @@ void A_GuardChase(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_EggShield(mobj_t *actor)
+void A_EggShield(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 i;
 	player_t *player;
 	fixed_t blockdist;
@@ -6042,8 +6136,9 @@ void A_EggShield(mobj_t *actor)
 // var1 = 1 (use value in var2); 0 (use info table value)
 // var2 = if var1 = 1, then value to set
 //
-void A_SetReactionTime(mobj_t *actor)
+void A_SetReactionTime(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_SETREACTIONTIME, actor))
 		return;
 
@@ -6060,8 +6155,9 @@ void A_SetReactionTime(mobj_t *actor)
 // var1 = ball number
 // var2 = total balls
 //
-void A_Boss1Spikeballs(mobj_t *actor)
+void A_Boss1Spikeballs(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *ball;
@@ -6076,7 +6172,7 @@ void A_Boss1Spikeballs(mobj_t *actor)
 
 	S_StartSound(ball, ball->info->seesound);
 	var1 = ball->state->var1, var2 = ball->state->var2;
-	ball->state->action.acp1(ball);
+	ball->state->action(ball);
 }
 
 // Function: A_Boss3TakeDamage
@@ -6086,8 +6182,9 @@ void A_Boss1Spikeballs(mobj_t *actor)
 // var1 = movecount value
 // var2 = unused
 //
-void A_Boss3TakeDamage(mobj_t *actor)
+void A_Boss3TakeDamage(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_BOSS3TAKEDAMAGE, actor))
 		return;
 
@@ -6104,8 +6201,9 @@ void A_Boss3TakeDamage(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_Boss3Path(mobj_t *actor)
+void A_Boss3Path(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_BOSS3PATH, actor))
 		return;
 
@@ -6142,7 +6240,7 @@ void A_Boss3Path(mobj_t *actor)
 		// the number
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 				continue;
 
 			mo2 = (mobj_t *)th;
@@ -6227,8 +6325,9 @@ void A_Boss3Path(mobj_t *actor)
 // var1 = tag
 // var2 = add angle to tag (optional)
 //
-void A_LinedefExecute(mobj_t *actor)
+void A_LinedefExecute(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 tagnum;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
@@ -6255,8 +6354,9 @@ void A_LinedefExecute(mobj_t *actor)
 // var1 = mapthing arg to take tag from
 // var2 = unused
 //
-void A_LinedefExecuteFromArg(mobj_t *actor)
+void A_LinedefExecuteFromArg(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 tagnum;
 	INT32 locvar1 = var1;
 
@@ -6284,8 +6384,9 @@ void A_LinedefExecuteFromArg(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_PlaySeeSound(mobj_t *actor)
+void A_PlaySeeSound(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_PLAYSEESOUND, actor))
 		return;
 
@@ -6300,8 +6401,9 @@ void A_PlaySeeSound(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_PlayAttackSound(mobj_t *actor)
+void A_PlayAttackSound(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_PLAYATTACKSOUND, actor))
 		return;
 
@@ -6316,8 +6418,9 @@ void A_PlayAttackSound(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_PlayActiveSound(mobj_t *actor)
+void A_PlayActiveSound(void *thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_PLAYACTIVESOUND, actor))
 		return;
 
@@ -6332,8 +6435,9 @@ void A_PlayActiveSound(mobj_t *actor)
 // var1 = object # to spawn as smoke
 // var2 = unused
 //
-void A_SmokeTrailer(mobj_t *actor)
+void A_SmokeTrailer(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *th;
 	INT32 locvar1 = var1;
 
@@ -6370,8 +6474,9 @@ void A_SmokeTrailer(mobj_t *actor)
 //		var2 >> 16 = z
 //		var2 & 65535 = type
 //
-void A_SpawnObjectAbsolute(mobj_t *actor)
+void A_SpawnObjectAbsolute(void *thing)
 {
+	mobj_t *actor = thing;
 	INT16 x, y, z; // Want to be sure we can use negative values
 	mobjtype_t type;
 	mobj_t *mo;
@@ -6406,8 +6511,9 @@ void A_SpawnObjectAbsolute(mobj_t *actor)
 //		var2 >> 16 = z
 //		var2 & 65535 = type
 //
-void A_SpawnObjectRelative(mobj_t *actor)
+void A_SpawnObjectRelative(void *thing)
 {
+	mobj_t *actor = thing;
 	INT16 x, y, z; // Want to be sure we can use negative values
 	mobjtype_t type;
 	mobj_t *mo;
@@ -6445,8 +6551,9 @@ void A_SpawnObjectRelative(mobj_t *actor)
 // var1 = min
 // var2 = max
 //
-void A_ChangeAngleRelative(mobj_t *actor)
+void A_ChangeAngleRelative(void *thing)
 {
+	mobj_t *actor = thing;
 	// Oh god, the old code /sucked/. Changed this and the absolute version to get a random range using amin and amax instead of
 	//  getting a random angle from the _entire_ spectrum and then clipping. While we're at it, do the angle conversion to the result
 	//  rather than the ranges, so <0 and >360 work as possible values. -Red
@@ -6481,8 +6588,9 @@ void A_ChangeAngleRelative(mobj_t *actor)
 // var1 = min
 // var2 = max
 //
-void A_ChangeAngleAbsolute(mobj_t *actor)
+void A_ChangeAngleAbsolute(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	//angle_t angle = (P_RandomByte()+1)<<24;
@@ -6514,8 +6622,9 @@ void A_ChangeAngleAbsolute(mobj_t *actor)
 // var1 = angle
 // var2 = relative? (default)
 //
-void A_RollAngle(mobj_t *actor)
+void A_RollAngle(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	const angle_t angle = FixedAngle(locvar1*FRACUNIT);
@@ -6538,8 +6647,9 @@ void A_RollAngle(mobj_t *actor)
 // var1 = min
 // var2 = max
 //
-void A_ChangeRollAngleRelative(mobj_t *actor)
+void A_ChangeRollAngleRelative(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	const fixed_t amin = locvar1*FRACUNIT;
@@ -6563,8 +6673,9 @@ void A_ChangeRollAngleRelative(mobj_t *actor)
 // var1 = min
 // var2 = max
 //
-void A_ChangeRollAngleAbsolute(mobj_t *actor)
+void A_ChangeRollAngleAbsolute(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	const fixed_t amin = locvar1*FRACUNIT;
@@ -6590,8 +6701,9 @@ void A_ChangeRollAngleAbsolute(mobj_t *actor)
 //		lower 16 bits = If 1, play sound using calling object as origin. If 0, play sound without an origin
 //		upper 16 bits = If 1, do not play sound during preticker.
 //
-void A_PlaySound(mobj_t *actor)
+void A_PlaySound(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -6611,8 +6723,9 @@ void A_PlaySound(mobj_t *actor)
 // var1 = mobj type
 // var2 = if (0) nearest; else furthest;
 //
-void A_FindTarget(mobj_t *actor)
+void A_FindTarget(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *targetedmobj = NULL;
@@ -6628,7 +6741,7 @@ void A_FindTarget(mobj_t *actor)
 	// scan the thinkers
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo2 = (mobj_t *)th;
@@ -6675,8 +6788,9 @@ void A_FindTarget(mobj_t *actor)
 // var1 = mobj type
 // var2 = if (0) nearest; else furthest;
 //
-void A_FindTracer(mobj_t *actor)
+void A_FindTracer(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *targetedmobj = NULL;
@@ -6692,7 +6806,7 @@ void A_FindTracer(mobj_t *actor)
 	// scan the thinkers
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo2 = (mobj_t *)th;
@@ -6739,8 +6853,9 @@ void A_FindTracer(mobj_t *actor)
 // var1 = tics to set to
 // var2 = if this is set, and no var1 is supplied, the mobj's threshold value will be used.
 //
-void A_SetTics(mobj_t *actor)
+void A_SetTics(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -6760,8 +6875,9 @@ void A_SetTics(mobj_t *actor)
 // var1 = lower bound
 // var2 = upper bound
 //
-void A_SetRandomTics(mobj_t *actor)
+void A_SetRandomTics(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -6778,8 +6894,9 @@ void A_SetRandomTics(mobj_t *actor)
 // var1 = if (var1 > 0), find target and add its color value to yours
 // var2 = if (var1 = 0), color value to add
 //
-void A_ChangeColorRelative(mobj_t *actor)
+void A_ChangeColorRelative(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -6803,8 +6920,9 @@ void A_ChangeColorRelative(mobj_t *actor)
 // var1 = if (var1 > 0), set your color to your target's color
 // var2 = if (var1 = 0), color value to set to
 //
-void A_ChangeColorAbsolute(mobj_t *actor)
+void A_ChangeColorAbsolute(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -6827,8 +6945,9 @@ void A_ChangeColorAbsolute(mobj_t *actor)
 // var1 = if (var1 != 0), dye your target instead of yourself
 // var2 = color value to dye
 //
-void A_Dye(mobj_t *actor)
+void A_Dye(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -6862,8 +6981,9 @@ void A_Dye(mobj_t *actor)
 // var1 = angle
 // var2 = force
 //
-void A_MoveRelative(mobj_t *actor)
+void A_MoveRelative(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -6880,8 +7000,9 @@ void A_MoveRelative(mobj_t *actor)
 // var1 = angle
 // var2 = force
 //
-void A_MoveAbsolute(mobj_t *actor)
+void A_MoveAbsolute(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -6898,8 +7019,9 @@ void A_MoveAbsolute(mobj_t *actor)
 // var1 = amount of force
 // var2 = If 1, xy momentum is lost. If 0, xy momentum is kept
 //
-void A_Thrust(mobj_t *actor)
+void A_Thrust(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -6924,8 +7046,9 @@ void A_Thrust(mobj_t *actor)
 //		lower 16 bits = If 1, xy momentum is lost. If 0, xy momentum is kept
 //		upper 16 bits = If 1, z momentum is lost. If 0, z momentum is kept
 //
-void A_ZThrust(mobj_t *actor)
+void A_ZThrust(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -6957,8 +7080,9 @@ void A_ZThrust(mobj_t *actor)
 //		0 = target/tracer's target
 //		1 = target/tracer's tracer
 //
-void A_SetTargetsTarget(mobj_t *actor)
+void A_SetTargetsTarget(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *oldtarg = NULL, *newtarg = NULL;
@@ -7001,8 +7125,9 @@ void A_SetTargetsTarget(mobj_t *actor)
 //		else if var2 == 1, remove the flag from the current flags
 //		else if var2 == 0, set the flags to the exact value
 //
-void A_SetObjectFlags(mobj_t *actor)
+void A_SetObjectFlags(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	boolean unlinkthings = false;
@@ -7043,8 +7168,9 @@ void A_SetObjectFlags(mobj_t *actor)
 //		else if var2 == 1, remove the flag from the current flags
 //		else if var2 == 0, set the flags to the exact value
 //
-void A_SetObjectFlags2(mobj_t *actor)
+void A_SetObjectFlags2(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -7070,8 +7196,9 @@ void A_SetObjectFlags2(mobj_t *actor)
 //		3 - Boss 4 jet flame
 // var2 = unused
 //
-void A_BossJetFume(mobj_t *actor)
+void A_BossJetFume(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *filler;
 	INT32 locvar1 = var1;
 
@@ -7180,8 +7307,9 @@ void A_BossJetFume(mobj_t *actor)
 // var1 = state number 1
 // var2 = state number 2
 //
-void A_RandomState(mobj_t *actor)
+void A_RandomState(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -7198,8 +7326,9 @@ void A_RandomState(mobj_t *actor)
 // var1 = Minimum state number to choose.
 // var2 = Maximum state number to use.
 //
-void A_RandomStateRange(mobj_t *actor)
+void A_RandomStateRange(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -7216,8 +7345,9 @@ void A_RandomStateRange(mobj_t *actor)
 // var1 = Minimum state number to use.
 // var2 = Maximum state number to use. The difference will act as a modulo operator.
 //
-void A_StateRangeByAngle(mobj_t *actor)
+void A_StateRangeByAngle(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -7237,8 +7367,9 @@ void A_StateRangeByAngle(mobj_t *actor)
 // var1 = Minimum state number to use.
 // var2 = Maximum state number to use. The difference will act as a modulo operator.
 //
-void A_StateRangeByParameter(mobj_t *actor)
+void A_StateRangeByParameter(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	UINT8 parameter = 0;
@@ -7278,8 +7409,9 @@ void A_StateRangeByParameter(mobj_t *actor)
 // var1 = state # to use 1st action from
 // var2 = state # to use 2nd action from
 //
-void A_DualAction(mobj_t *actor)
+void A_DualAction(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -7293,14 +7425,14 @@ void A_DualAction(mobj_t *actor)
 	astate = &states[locvar1];
 
 	CONS_Debug(DBG_GAMELOGIC, "A_DualAction: Calling First Action (state %d)...\n", locvar1);
-	states[locvar1].action.acp1(actor);
+	states[locvar1].action(actor);
 
 	var1 = states[locvar2].var1;
 	var2 = states[locvar2].var2;
 	astate = &states[locvar2];
 
 	CONS_Debug(DBG_GAMELOGIC, "A_DualAction: Calling Second Action (state %d)...\n", locvar2);
-	states[locvar2].action.acp1(actor);
+	states[locvar2].action(actor);
 }
 
 // Function: A_RemoteAction
@@ -7310,8 +7442,9 @@ void A_DualAction(mobj_t *actor)
 // var1 = remote object (-2 uses tracer, -1 uses target)
 // var2 = state reference for calling an action
 //
-void A_RemoteAction(mobj_t *actor)
+void A_RemoteAction(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *originaltarget = actor->target; // Hold on to the target for later.
@@ -7331,7 +7464,7 @@ void A_RemoteAction(mobj_t *actor)
 		// scan the thinkers
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 				continue;
 
 			mo2 = (mobj_t *)th;
@@ -7383,7 +7516,7 @@ void A_RemoteAction(mobj_t *actor)
 
 		CONS_Debug(DBG_GAMELOGIC, "A_RemoteAction: Calling action on %p\n"
 				"var1 is %d\nvar2 is %d\n", (void*)actor->target, var1, var2);
-		states[locvar2].action.acp1(actor->target);
+		states[locvar2].action(actor->target);
 	}
 
 	P_SetTarget(&actor->target, originaltarget); // Restore the original target.
@@ -7396,8 +7529,9 @@ void A_RemoteAction(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_ToggleFlameJet(mobj_t* actor)
+void A_ToggleFlameJet(void* thing)
 {
+	mobj_t *actor = thing;
 	if (LUA_CallAction(A_TOGGLEFLAMEJET, actor))
 		return;
 
@@ -7438,8 +7572,9 @@ void A_ToggleFlameJet(mobj_t* actor)
 //        Bits 1-10: X factor
 //        Bits 11-20: Y factor
 //        Bits 21-30: Z factor
-void A_OrbitNights(mobj_t* actor)
+void A_OrbitNights(void* thing)
 {
+	mobj_t *actor = thing;
 	INT32 ofs = (var2 & 0x3FF);
 	boolean ishelper = (var2 & 0x10000);
 	boolean donotrescale = (var2 & 0x40000);
@@ -7502,8 +7637,9 @@ void A_OrbitNights(mobj_t* actor)
 // var1 = duration in tics
 // var2 = unused
 //
-void A_GhostMe(mobj_t *actor)
+void A_GhostMe(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	mobj_t *ghost;
 
@@ -7524,8 +7660,9 @@ void A_GhostMe(mobj_t *actor)
 //		0 = target
 //		1 = tracer
 //
-void A_SetObjectState(mobj_t *actor)
+void A_SetObjectState(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *target;
@@ -7563,8 +7700,9 @@ void A_SetObjectState(mobj_t *actor)
 //		lower 16 bits = type
 //		upper 16 bits = range (if == 0, across whole map)
 //
-void A_SetObjectTypeState(mobj_t *actor)
+void A_SetObjectTypeState(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	const UINT16 loc2lw = (UINT16)(locvar2 & 65535);
@@ -7579,7 +7717,7 @@ void A_SetObjectTypeState(mobj_t *actor)
 
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo2 = (mobj_t *)th;
@@ -7611,8 +7749,9 @@ void A_SetObjectTypeState(mobj_t *actor)
 //		1 = tracer
 // var2 = unused
 //
-void A_KnockBack(mobj_t *actor)
+void A_KnockBack(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	mobj_t *target;
 
@@ -7644,8 +7783,9 @@ void A_KnockBack(mobj_t *actor)
 //		lower 16 bits = If 1, xy momentum is lost. If 0, xy momentum is kept
 //		upper 16 bits = 0 - target, 1 - tracer
 //
-void A_PushAway(mobj_t *actor)
+void A_PushAway(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *target; // target
@@ -7680,8 +7820,9 @@ void A_PushAway(mobj_t *actor)
 // var1 = ammount of drained rings
 // var2 = unused
 //
-void A_RingDrain(mobj_t *actor)
+void A_RingDrain(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	player_t *player;
 
@@ -7708,8 +7849,9 @@ void A_RingDrain(mobj_t *actor)
 //		lower 16 bits = missile type
 //		upper 16 bits = height offset
 //
-void A_SplitShot(mobj_t *actor)
+void A_SplitShot(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	const UINT16 loc2lw = (UINT16)(locvar2 & 65535);
@@ -7749,8 +7891,9 @@ void A_SplitShot(mobj_t *actor)
 // var1 = splitting missile type
 // var2 = splitting angle
 //
-void A_MissileSplit(mobj_t *actor)
+void A_MissileSplit(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -7772,8 +7915,9 @@ void A_MissileSplit(mobj_t *actor)
 //		upper 16 bits = missile type #
 // var2 = height offset
 //
-void A_MultiShot(mobj_t *actor)
+void A_MultiShot(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t z, xr, yr;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
@@ -7832,8 +7976,9 @@ void A_MultiShot(mobj_t *actor)
 //		upper 16 bits = maximum step #
 // var2 = force
 //
-void A_InstaLoop(mobj_t *actor)
+void A_InstaLoop(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	fixed_t force = max(locvar2, 1)*FRACUNIT; // defaults to 1 if var2 < 1
@@ -7861,8 +8006,9 @@ void A_InstaLoop(mobj_t *actor)
 //		lower 16 bits = vertical rotation speed in 1/10 fracunits per tic
 //		upper 16 bits = horizontal rotation speed in 1/10 fracunits per tic
 //
-void A_Custom3DRotate(mobj_t *actor)
+void A_Custom3DRotate(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -7931,8 +8077,9 @@ void A_Custom3DRotate(mobj_t *actor)
 //		else, do not call a specific state if no players are available
 // var2 = state number
 //
-void A_SearchForPlayers(mobj_t *actor)
+void A_SearchForPlayers(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -7962,8 +8109,9 @@ void A_SearchForPlayers(mobj_t *actor)
 //		upper 16 bits = numerator (defaults to 1 if zero)
 // var2 = state number
 //
-void A_CheckRandom(mobj_t *actor)
+void A_CheckRandom(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	fixed_t chance = FRACUNIT;
@@ -7990,8 +8138,9 @@ void A_CheckRandom(mobj_t *actor)
 // var1 = if player rings >= var1 call state
 // var2 = state number
 //
-void A_CheckTargetRings(mobj_t *actor)
+void A_CheckTargetRings(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -8012,8 +8161,9 @@ void A_CheckTargetRings(mobj_t *actor)
 // var1 = if player rings >= var1 call state
 // var2 = state number
 //
-void A_CheckRings(mobj_t *actor)
+void A_CheckRings(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	INT32 i, cntr = 0;
@@ -8035,8 +8185,9 @@ void A_CheckRings(mobj_t *actor)
 // var1 = if total player rings >= var1 call state
 // var2 = state number
 //
-void A_CheckTotalRings(mobj_t *actor)
+void A_CheckTotalRings(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -8059,8 +8210,9 @@ void A_CheckTotalRings(mobj_t *actor)
 // var1 = if health <= var1 call state
 // var2 = state number
 //
-void A_CheckHealth(mobj_t *actor)
+void A_CheckHealth(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -8080,8 +8232,9 @@ void A_CheckHealth(mobj_t *actor)
 //		upper 16 bits = 0 - target, 1 - tracer
 // var2 = state number
 //
-void A_CheckRange(mobj_t *actor)
+void A_CheckRange(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	fixed_t dist;
@@ -8110,8 +8263,9 @@ void A_CheckRange(mobj_t *actor)
 //		upper 16 bits = 0 - target, 1 - tracer
 // var2 = state number
 //
-void A_CheckHeight(mobj_t *actor)
+void A_CheckHeight(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	fixed_t height;
@@ -8140,8 +8294,9 @@ void A_CheckHeight(mobj_t *actor)
 //		upper 16 bits = 0 - target, 1 - tracer
 // var2 = state number
 //
-void A_CheckTrueRange(mobj_t *actor)
+void A_CheckTrueRange(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	fixed_t height; // vertical range
@@ -8184,8 +8339,9 @@ void A_CheckTrueRange(mobj_t *actor)
 //		lower 16 bits = state to call
 //		upper 16 bits = range (if == 0, check whole map)
 //
-void A_CheckThingCount(mobj_t *actor)
+void A_CheckThingCount(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -8204,7 +8360,7 @@ void A_CheckThingCount(mobj_t *actor)
 
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo2 = (mobj_t *)th;
@@ -8236,8 +8392,9 @@ void A_CheckThingCount(mobj_t *actor)
 //		1 = tracer
 // var2 = state number
 //
-void A_CheckAmbush(mobj_t *actor)
+void A_CheckAmbush(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	angle_t at; // angle target is currently facing
@@ -8277,8 +8434,9 @@ void A_CheckAmbush(mobj_t *actor)
 // var1 = if custom value >= var1, call state
 // var2 = state number
 //
-void A_CheckCustomValue(mobj_t *actor)
+void A_CheckCustomValue(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -8296,8 +8454,9 @@ void A_CheckCustomValue(mobj_t *actor)
 // var1 = if memory value >= var1, call state
 // var2 = state number
 //
-void A_CheckCusValMemo(mobj_t *actor)
+void A_CheckCusValMemo(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -8321,8 +8480,9 @@ void A_CheckCusValMemo(mobj_t *actor)
 //      else if var2 == 1, substract var1 from the custom value
 //      else if var2 == 0, replace the custom value with var1
 //
-void A_SetCustomValue(mobj_t *actor)
+void A_SetCustomValue(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -8368,8 +8528,9 @@ void A_SetCustomValue(mobj_t *actor)
 //      else if var2 == 1,  mem -= cv  ||  cv -= mem
 //      else mem = cv  ||  cv = mem
 //
-void A_UseCusValMemo(mobj_t *actor)
+void A_UseCusValMemo(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -8431,8 +8592,9 @@ void A_UseCusValMemo(mobj_t *actor)
 //      else if var2 == 1, substract var1 from the target's custom value
 //      else if var2 == 0, replace the target's custom value with var1
 //
-void A_RelayCustomValue(mobj_t *actor)
+void A_RelayCustomValue(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -8493,8 +8655,9 @@ void A_RelayCustomValue(mobj_t *actor)
 //      else if var2 == 1, only replace new action's var2 with custom value
 //      else if var2 == 0, only replace new action's var1 with custom value
 //
-void A_CusValAction(mobj_t *actor)
+void A_CusValAction(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -8533,7 +8696,7 @@ void A_CusValAction(mobj_t *actor)
 	}
 
 	astate = &states[locvar1];
-	states[locvar1].action.acp1(actor);
+	states[locvar1].action(actor);
 }
 
 // Function: A_ForceStop
@@ -8545,8 +8708,9 @@ void A_CusValAction(mobj_t *actor)
 //      else, stop x-y-movement only
 // var2 = unused
 //
-void A_ForceStop(mobj_t *actor)
+void A_ForceStop(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 
 	if (LUA_CallAction(A_FORCESTOP, actor))
@@ -8564,8 +8728,9 @@ void A_ForceStop(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_ForceWin(mobj_t *actor)
+void A_ForceWin(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 i;
 
 	if (LUA_CallAction(A_FORCEWIN, actor))
@@ -8593,8 +8758,9 @@ void A_ForceWin(mobj_t *actor)
 //        else, actor solid
 // var2 = unused
 //
-void A_SpikeRetract(mobj_t *actor)
+void A_SpikeRetract(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 
 	if (LUA_CallAction(A_SPIKERETRACT, actor))
@@ -8631,8 +8797,9 @@ void A_SpikeRetract(mobj_t *actor)
 //        else if var1 == 6, set actor to raisestate
 // var2 = unused
 //
-void A_InfoState(mobj_t *actor)
+void A_InfoState(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	switch (locvar1)
 	{
@@ -8676,8 +8843,9 @@ void A_InfoState(mobj_t *actor)
 // var1 = repeat count
 // var2 = state to return to if extravalue2 > 0
 //
-void A_Repeat(mobj_t *actor)
+void A_Repeat(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -8700,8 +8868,9 @@ void A_Repeat(mobj_t *actor)
 //        upper 16 bits: 0 = actor, 1 = target, 2 = tracer
 //        lower 16 bits: 0 = instant change, 1 = smooth change
 //
-void A_SetScale(mobj_t *actor)
+void A_SetScale(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *target;
@@ -8744,8 +8913,9 @@ void A_SetScale(mobj_t *actor)
 // var1 = Mobj affected: 0 - actor, 1 - target, 2 - tracer
 // var2 = Action: 0 - Damage, 1 - Kill, 2 - Remove
 //
-void A_RemoteDamage(mobj_t *actor)
+void A_RemoteDamage(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *target; // we MUST have a target
@@ -8797,8 +8967,9 @@ void A_RemoteDamage(mobj_t *actor)
 // var1 = speed multiple
 // var2 = destination: 0 = target, 1 = tracer
 //
-void A_HomingChase(mobj_t *actor)
+void A_HomingChase(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *dest;
@@ -8846,8 +9017,9 @@ void A_HomingChase(mobj_t *actor)
 //				use vertical angle variable as horizontal distance to cover during momz calculation
 //        upper 16 bits = height offset
 //
-void A_TrapShot(mobj_t *actor)
+void A_TrapShot(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	boolean oldstyle = (locvar2 & 32768) ? true : false;
@@ -8915,8 +9087,9 @@ void A_TrapShot(mobj_t *actor)
 // var1 = mobj to spawn
 // var2 = If 0, target only the actor's target. Else, target every player, period.
 //
-void A_VileTarget(mobj_t *actor)
+void A_VileTarget(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *fog;
@@ -9001,8 +9174,9 @@ void A_VileTarget(mobj_t *actor)
 //		Lower 16 bits = optional explosion object
 //		Upper 16 bits = If 0, attack only the actor's target. Else, attack all the players. All of them.
 //
-void A_VileAttack(mobj_t *actor)
+void A_VileAttack(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	sfxenum_t soundtoplay;
@@ -9116,8 +9290,9 @@ void A_VileAttack(mobj_t *actor)
 //		Lower 16 bits = mobj to spawn (0 doesn't spawn a line at all)
 //		Upper 16 bits = # to spawn (default is 8)
 //
-void A_VileFire(mobj_t *actor)
+void A_VileFire(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	mobj_t *dest;
@@ -9200,8 +9375,9 @@ void A_VileFire(mobj_t *actor)
 // var1 = lower-bound of frame length, in tics
 // var2 = optional sound to play
 //
-void A_BrakChase(mobj_t *actor)
+void A_BrakChase(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 delta;
 	INT32 lowerbound;
 	INT32 newtics;
@@ -9323,8 +9499,9 @@ void A_BrakChase(mobj_t *actor)
 // var1 = object # to shoot
 // var2 = unused
 //
-void A_BrakFireShot(mobj_t *actor)
+void A_BrakFireShot(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t x, y, z;
 	INT32 locvar1 = var1;
 
@@ -9371,8 +9548,9 @@ void A_BrakFireShot(mobj_t *actor)
 //		Upper 16 bits: if 0, aim 1/3 of the way. Else, aim directly at target.
 //
 
-void A_BrakLobShot(mobj_t *actor)
+void A_BrakLobShot(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t v; // Velocity to shoot object
 	fixed_t a1, a2, aToUse; // Velocity squared
 	fixed_t g; // Gravity
@@ -9482,8 +9660,9 @@ void A_BrakLobShot(mobj_t *actor)
 //		Lower 16 bits: distance to toss them (No default - 0 does just that - but negatives will revert to 128)
 //		Upper 16 bits: airtime in tics (default 16)
 //
-void A_NapalmScatter(mobj_t *actor)
+void A_NapalmScatter(void *thing)
 {
+	mobj_t *actor = thing;
 	mobjtype_t typeOfShot = var1 & 0x0000FFFF; // Type
 	INT32 numToShoot = (var1 & 0xFFFF0000) >> 16; // How many
 	fixed_t distance = (var2 & 0x0000FFFF) << FRACBITS; // How far
@@ -9539,8 +9718,9 @@ void A_NapalmScatter(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_SpawnFreshCopy(mobj_t *actor)
+void A_SpawnFreshCopy(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *newObject;
 
 	if (LUA_CallAction(A_SPAWNFRESHCOPY, actor))
@@ -9614,8 +9794,9 @@ mobj_t *P_InternalFlickySpawn(mobj_t *actor, mobjtype_t flickytype, fixed_t momz
 //		bit 19: if 1, spawn flicky slightly backward from spawn position. doesn't stack with 18.
 // var2 = upwards thrust for spawned flicky. If zero, default value is provided.
 //
-void A_FlickySpawn(mobj_t *actor)
+void A_FlickySpawn(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1 & 65535;
 	INT32 locvar2 = var2;
 	INT32 test = (var1 >> 16);
@@ -9677,8 +9858,9 @@ void P_InternalFlickySetColor(mobj_t *actor, UINT8 color)
 // If TMFF_STATIONARY (MF_GRENADEBOUNCE): Flickies stand in-place without gravity (unless they hop, then gravity is applied.)
 // If TMFF_HOP (MF_NOCLIPTHING): is flagged, Flickies hop.
 //
-void A_FlickyCenter(mobj_t *actor)
+void A_FlickyCenter(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	fixed_t homeRadius = INT32_MAX;
@@ -9755,6 +9937,7 @@ void A_FlickyCenter(mobj_t *actor)
 // Internal Flicky bubbling function.
 void P_InternalFlickyBubble(mobj_t *actor)
 {
+
 	if (actor->eflags & MFE_UNDERWATER)
 	{
 		mobj_t *overlay;
@@ -9783,8 +9966,9 @@ void P_InternalFlickyBubble(mobj_t *actor)
 // var1 = how far around the target (in angle constants) the flicky should look
 // var2 = distance from target to aim for
 //
-void A_FlickyAim(mobj_t *actor)
+void A_FlickyAim(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	boolean flickyhitwall = false;
@@ -9884,8 +10068,9 @@ void P_InternalFlickyFly(mobj_t *actor, fixed_t flyspeed, fixed_t targetdist, fi
 // var1 = how fast to fly
 // var2 = how far ahead the target should be considered
 //
-void A_FlickyFly(mobj_t *actor)
+void A_FlickyFly(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -9904,8 +10089,9 @@ void A_FlickyFly(mobj_t *actor)
 // var1 = how fast to fly
 // var2 = how far ahead the target should be considered
 //
-void A_FlickySoar(mobj_t *actor)
+void A_FlickySoar(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -9928,8 +10114,9 @@ void A_FlickySoar(mobj_t *actor)
 // var2 = state to change to upon slowing down
 // the spawnstate of the mobj = state to change to when above water
 //
-void A_FlickyCoast(mobj_t *actor)
+void A_FlickyCoast(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -9975,8 +10162,9 @@ void P_InternalFlickyHop(mobj_t *actor, fixed_t momz, fixed_t momh, angle_t angl
 // var1 = vertical thrust
 // var2 = horizontal thrust
 //
-void A_FlickyHop(mobj_t *actor)
+void A_FlickyHop(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -9993,8 +10181,9 @@ void A_FlickyHop(mobj_t *actor)
 // var1 = intended vertical thrust
 // var2 = intended horizontal thrust
 //
-void A_FlickyFlounder(mobj_t *actor)
+void A_FlickyFlounder(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	angle_t hopangle;
@@ -10016,8 +10205,9 @@ void A_FlickyFlounder(mobj_t *actor)
 // var2 = state to change to upon falling
 // the meleestate of the mobj = state to change to when underwater
 //
-void A_FlickyCheck(mobj_t *actor)
+void A_FlickyCheck(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -10053,8 +10243,9 @@ void A_FlickyCheck(mobj_t *actor)
 // var1 = state to change to when falling below height relative to target
 // var2 = height relative to target to change state at
 //
-void A_FlickyHeightCheck(mobj_t *actor)
+void A_FlickyHeightCheck(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -10088,8 +10279,9 @@ void A_FlickyHeightCheck(mobj_t *actor)
 // var2 = state to change to upon falling
 // the meleestate of the mobj = state to change to when underwater
 //
-void A_FlickyFlutter(mobj_t *actor)
+void A_FlickyFlutter(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -10118,8 +10310,9 @@ void A_FlickyFlutter(mobj_t *actor)
 // var1 = unused
 // var2 = unused
 //
-void A_FlameParticle(mobj_t *actor)
+void A_FlameParticle(void *thing)
 {
+	mobj_t *actor = thing;
 	mobjtype_t type = (mobjtype_t)(mobjinfo[actor->type].painchance);
 	fixed_t rad, hei;
 	mobj_t *particle;
@@ -10152,8 +10345,9 @@ void A_FlameParticle(mobj_t *actor)
 // var1 = bit 1 = bit 1 = don't make fast, bit 2 = don't set tracer
 // var2 = unused
 //
-void A_FadeOverlay(mobj_t *actor)
+void A_FadeOverlay(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *fade;
 	INT32 locvar1 = var1;
 
@@ -10181,8 +10375,9 @@ void A_FadeOverlay(mobj_t *actor)
 // var1 = Object type to connect to ground
 // var2 = Object type to place on ground
 //
-void A_ConnectToGround(mobj_t *actor)
+void A_ConnectToGround(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *work;
 	fixed_t workz;
 	fixed_t workh;
@@ -10241,8 +10436,9 @@ void A_ConnectToGround(mobj_t *actor)
 //		var2 >> 16 = z
 //		var2 & 65535 = state
 //
-void A_SpawnParticleRelative(mobj_t *actor)
+void A_SpawnParticleRelative(void *thing)
 {
+	mobj_t *actor = thing;
 	INT16 x, y, z; // Want to be sure we can use negative values
 	statenum_t state;
 	mobj_t *mo;
@@ -10274,8 +10470,9 @@ void A_SpawnParticleRelative(mobj_t *actor)
 	P_SetMobjState(mo, state);
 }
 
-void A_ParticleSpawn(mobj_t *actor)
+void A_ParticleSpawn(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	fixed_t speed;
 	mobjtype_t type;
@@ -10315,8 +10512,9 @@ void A_ParticleSpawn(mobj_t *actor)
 // var1 = same as A_MultiShot
 // var2 = same as A_MultiShot
 //
-void A_MultiShotDist(mobj_t *actor)
+void A_MultiShotDist(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -10347,8 +10545,9 @@ void A_MultiShotDist(mobj_t *actor)
 // var1 = mask
 // var2 = state to go
 //
-void A_CheckFlags2(mobj_t *actor)
+void A_CheckFlags2(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -10366,8 +10565,9 @@ void A_CheckFlags2(mobj_t *actor)
 // var1 = state to change to upon being slow enough
 // var2 = minimum speed
 //
-void A_DoNPCSkid(mobj_t *actor)
+void A_DoNPCSkid(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	fixed_t x, y, z;
@@ -10421,8 +10621,9 @@ void A_DoNPCSkid(mobj_t *actor)
 //        Otherwise, vertical and horizontal speed
 //        will be multiplied by this.
 //
-void A_DoNPCPain(mobj_t *actor)
+void A_DoNPCPain(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	fixed_t vspeed = 0;
@@ -10472,8 +10673,9 @@ void A_DoNPCPain(mobj_t *actor)
 // var1 = value to set extravalue2 to
 // var2 = unused
 //
-void A_PrepareRepeat(mobj_t *actor)
+void A_PrepareRepeat(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 
 	if (LUA_CallAction(A_PREPAREREPEAT, actor))
@@ -10490,8 +10692,9 @@ void A_PrepareRepeat(mobj_t *actor)
 // var1 upper 16 bits = distance limit
 // var2 = unused
 //
-void A_LookForBetter(mobj_t *actor)
+void A_LookForBetter(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 
 	if (LUA_CallAction(A_LOOKFORBETTER, actor))
@@ -10508,8 +10711,9 @@ void A_LookForBetter(mobj_t *actor)
 // var1 = Modulo
 // var2 = State
 //
-void A_ModuloToState(mobj_t *actor)
+void A_ModuloToState(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 
@@ -10530,8 +10734,9 @@ void A_ModuloToState(mobj_t *actor)
 //     &1: height is absolute
 //     &2: scale with actor's scale
 //
-void A_ChangeHeight(mobj_t *actor)
+void A_ChangeHeight(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 locvar1 = var1;
 	INT32 locvar2 = var2;
 	fixed_t height = locvar1;
@@ -10565,9 +10770,9 @@ void A_ChangeHeight(mobj_t *actor)
 // SRB2Kart
 //
 
-void A_ItemPop(mobj_t *actor)
+void A_ItemPop(void *thing)
 {
-
+	mobj_t *actor = thing;
 	mobj_t *remains;
 	mobjtype_t explode;
 
@@ -10652,8 +10857,9 @@ void A_ItemPop(mobj_t *actor)
 	P_RemoveMobj(actor);
 }
 
-void A_JawzChase(mobj_t *actor)
+void A_JawzChase(void *thing)
 {
+	mobj_t *actor = thing;
 	player_t *player;
 
 	if (LUA_CallAction(A_JAWZCHASE, actor))
@@ -10694,8 +10900,9 @@ void A_JawzChase(mobj_t *actor)
 	return;
 }
 
-void A_JawzExplode(mobj_t *actor)
+void A_JawzExplode(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 shrapnel = 2;
 	mobj_t *truc;
 
@@ -10737,8 +10944,9 @@ void A_JawzExplode(mobj_t *actor)
 	return;
 }
 
-void A_SPBChase(mobj_t *actor)
+void A_SPBChase(void *thing)
 {
+	mobj_t *actor = thing;
 	player_t *player = NULL;
 	UINT8 i;
 	UINT8 bestrank = UINT8_MAX;
@@ -11107,8 +11315,9 @@ static inline BlockItReturn_t PIT_SSMineSearch(mobj_t *thing)
 	return BMIT_ABORT;
 }
 
-void A_SSMineSearch(mobj_t *actor)
+void A_SSMineSearch(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 bx, by, xl, xh, yl, yh;
 	explodedist = FixedMul(actor->info->painchance, mapobjectscale);
 
@@ -11171,8 +11380,9 @@ static inline BlockItReturn_t PIT_MineExplode(mobj_t *thing)
 	return BMIT_CONTINUE;
 }
 
-void A_SSMineExplode(mobj_t *actor)
+void A_SSMineExplode(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 bx, by, xl, xh, yl, yh;
 	INT32 d;
 	INT32 locvar1 = var1;
@@ -11215,9 +11425,9 @@ void A_SSMineExplode(mobj_t *actor)
 	actor->flags2 |= MF2_DEBRIS;	// Set this flag to ensure that the explosion won't be effective more than 1 frame.
 }
 
-void A_LandMineExplode(mobj_t *actor)
+void A_LandMineExplode(void *thing)
 {
-
+	mobj_t *actor = thing;
 	mobj_t *expl;
 	INT32 colour = SKINCOLOR_KETCHUP;	// we spell words properly here
 	INT32 i;
@@ -11257,8 +11467,9 @@ void A_LandMineExplode(mobj_t *actor)
 	}
 }
 
-void A_BallhogExplode(mobj_t *actor)
+void A_BallhogExplode(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *mo2;
 
 	if (LUA_CallAction(A_BALLHOGEXPLODE, actor))
@@ -11273,8 +11484,9 @@ void A_BallhogExplode(mobj_t *actor)
 
 // A_LightningFollowPlayer:
 // Dumb simple function that gives a mobj its target's momentums without updating its angle.
-void A_LightningFollowPlayer(mobj_t *actor)
+void A_LightningFollowPlayer(void *thing)
 {
+	mobj_t *actor = thing;
 	fixed_t sx, sy;
 
 	if (LUA_CallAction(A_LIGHTNINGFOLLOWPLAYER, actor))
@@ -11302,8 +11514,9 @@ void A_LightningFollowPlayer(mobj_t *actor)
 
 // A_FZBoomFlash:
 // Flash everyone close enough to the boom
-void A_FZBoomFlash(mobj_t *actor)
+void A_FZBoomFlash(void *thing)
 {
+	mobj_t *actor = thing;
 	UINT8 i;
 
 	if (LUA_CallAction(A_FZBOOMFLASH, actor))
@@ -11324,8 +11537,9 @@ void A_FZBoomFlash(mobj_t *actor)
 // A_FZBoomSmoke:
 // Spawns pinkish smoke around the object
 // Var1 is radius add
-void A_FZBoomSmoke(mobj_t *actor)
+void A_FZBoomSmoke(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 i;
 	INT32 rad = 47+(23*var1);
 
@@ -11353,8 +11567,9 @@ void A_FZBoomSmoke(mobj_t *actor)
 
 // A_RandomShadowFrame
 // Gives a random sprite for the Mayonaka static shadows. Dumb and simple.
-void A_RandomShadowFrame(mobj_t *actor)
+void A_RandomShadowFrame(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *fire;
 	mobj_t *fake;
 
@@ -11401,8 +11616,9 @@ void A_RandomShadowFrame(mobj_t *actor)
 
 // A_RoamingShadowThinker
 // Thinker for Midnight Channel's Roaming Shadows:
-void A_RoamingShadowThinker(mobj_t *actor)
+void A_RoamingShadowThinker(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *wind;
 
 	if (LUA_CallAction(A_ROAMINGSHADOWTHINKER, (actor)))
@@ -11458,8 +11674,9 @@ void A_RoamingShadowThinker(mobj_t *actor)
 // A_MayonakaArrow
 // Used for the arrow sprite animations in Mayonaka. It's only extra visual bullshit to make em more random.
 
-void A_MayonakaArrow(mobj_t *actor)
+void A_MayonakaArrow(void *thing)
 {
+	mobj_t *actor = thing;
 	INT32 flip = 0;
 	INT32 iswarning;
 
@@ -11497,8 +11714,9 @@ void A_MayonakaArrow(mobj_t *actor)
 // A_MementosTPParticles
 // Mementos teleporters particles effects. Short and simple.
 
-void A_MementosTPParticles(mobj_t *actor)
+void A_MementosTPParticles(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *particle;
 	mobj_t *mo2;
 	int i = 0;
@@ -11529,7 +11747,7 @@ void A_MementosTPParticles(mobj_t *actor)
 	{
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 				continue;
 
 			mo2 = (mobj_t *)th;
@@ -11545,8 +11763,9 @@ void A_MementosTPParticles(mobj_t *actor)
 // A_ReaperThinker
 // Mementos's Reaper's thinker. A huge pain in the Derek Bum to translate from Lua to this shite if you ask me.
 
-void A_ReaperThinker(mobj_t *actor)
+void A_ReaperThinker(void *thing)
 {
+	mobj_t *actor = thing;
 	mobj_t *particle;	// particles to spawn
 	int i = 0;			// for loops
 	angle_t an = ANGLE_22h;		// Reminder that angle constants suck.
@@ -11634,7 +11853,7 @@ void A_ReaperThinker(mobj_t *actor)
 		// We have no target and oughta find one, so let's scan through thinkers for a waypoint of angle 0, or something.
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 				continue;
 
 			mo2 = (mobj_t *)th;
@@ -11699,7 +11918,7 @@ void A_ReaperThinker(mobj_t *actor)
 				// If we reach close to a waypoint, then we should go to the NEXT one.
 				for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 				{
-					if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+					if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 						continue;
 
 					mo2 = (mobj_t *)th;
diff --git a/src/p_floor.c b/src/p_floor.c
index 1856a051b..071f07327 100644
--- a/src/p_floor.c
+++ b/src/p_floor.c
@@ -1688,7 +1688,7 @@ void EV_DoFloorOLD(mtag_t tag, line_t *line, floor_e floortype)
 		sec->floordata = dofloor;
 
 		// set up some generic aspects of the floormove_t
-		dofloor->thinker.function.acp1 = (actionf_p1)T_MoveFloor;
+		dofloor->thinker.function = (actionf_p1)T_MoveFloor;
 		dofloor->type = floortype;
 		dofloor->crush = false; // default: types that crush will change this
 		dofloor->sector = sec;
@@ -1809,7 +1809,7 @@ static floormove_t *CreateFloorThinker(sector_t *sec)
 	sec->floordata = dofloor;
 
 	// set up some generic aspects of the floormove_t
-	dofloor->thinker.function.acp1 = (actionf_p1)T_MoveFloor;
+	dofloor->thinker.function = (actionf_p1)T_MoveFloor;
 	dofloor->sector = sec;
 	dofloor->crush = false; // default: types that crush will change this
 
@@ -2103,7 +2103,7 @@ static elevator_t *CreateElevatorThinker(sector_t *sec)
 	sec->ceilingdata = elevator;
 
 	// set up some generic aspects of the floormove_t
-	elevator->thinker.function.acp1 = (actionf_p1)T_MoveElevator;
+	elevator->thinker.function = (actionf_p1)T_MoveElevator;
 	elevator->distance = 1; // Always crush unless otherwise
 	elevator->sector = sec;
 
@@ -2397,7 +2397,7 @@ void EV_BounceSector(sector_t *sec, fixed_t momz, line_t *sourceline)
 	bouncer = Z_Calloc(sizeof (*bouncer), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &bouncer->thinker);
 	sec->ceilingdata = bouncer;
-	bouncer->thinker.function.acp1 = (actionf_p1)T_BounceCheese;
+	bouncer->thinker.function = (actionf_p1)T_BounceCheese;
 
 	// set up the fields according to the type of elevator action
 	bouncer->sourceline = sourceline;
@@ -2423,7 +2423,7 @@ void EV_DoContinuousFall(sector_t *sec, sector_t *backsector, fixed_t spd, boole
 	// create and initialize new thinker
 	faller = Z_Calloc(sizeof (*faller), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &faller->thinker);
-	faller->thinker.function.acp1 = (actionf_p1)T_ContinuousFalling;
+	faller->thinker.function = (actionf_p1)T_ContinuousFalling;
 
 	// set up the fields
 	faller->sector = sec;
@@ -2459,7 +2459,7 @@ INT32 EV_StartCrumble(sector_t *sec, ffloor_t *rover, boolean floating,
 	// create and initialize new crumble thinker
 	crumble = Z_Calloc(sizeof (*crumble), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &crumble->thinker);
-	crumble->thinker.function.acp1 = (actionf_p1)T_StartCrumble;
+	crumble->thinker.function = (actionf_p1)T_StartCrumble;
 
 	// set up the fields
 	crumble->sector = sec;
@@ -2535,7 +2535,7 @@ void EV_MarioBlock(ffloor_t *rover, sector_t *sector, mobj_t *puncher)
 		P_AddThinker(THINK_MAIN, &block->thinker);
 		roversec->floordata = block;
 		roversec->ceilingdata = block;
-		block->thinker.function.acp1 = (actionf_p1)T_MarioBlock;
+		block->thinker.function = (actionf_p1)T_MarioBlock;
 
 		// Set up the fields
 		block->sector = roversec;
diff --git a/src/p_inter.c b/src/p_inter.c
index d37a8faab..08ec0f7a0 100644
--- a/src/p_inter.c
+++ b/src/p_inter.c
@@ -1509,7 +1509,7 @@ void P_KillMobj(mobj_t *target, mobj_t *inflictor, mobj_t *source, UINT8 damaget
 				// scan the thinkers to make sure all the old pinch dummies are gone on death
 				for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 				{
-					if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+					if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 						continue;
 
 					mo = (mobj_t *)th;
diff --git a/src/p_lights.c b/src/p_lights.c
index 0853ec2d7..4935d2934 100644
--- a/src/p_lights.c
+++ b/src/p_lights.c
@@ -78,7 +78,7 @@ fireflicker_t *P_SpawnAdjustableFireFlicker(sector_t *sector, INT16 lighta, INT1
 
 	P_AddThinker(THINK_MAIN, &flick->thinker);
 
-	flick->thinker.function.acp1 = (actionf_p1)T_FireFlicker;
+	flick->thinker.function = (actionf_p1)T_FireFlicker;
 	flick->sector = sector;
 	flick->maxlight = max(lighta, lightb);
 	flick->minlight = min(lighta, lightb);
@@ -136,7 +136,7 @@ void P_SpawnLightningFlash(sector_t *sector)
 
 	if (sector->lightingdata)
 	{
-		if (((lightflash_t *)sector->lightingdata)->thinker.function.acp1
+		if (((lightflash_t *)sector->lightingdata)->thinker.function
 			== (actionf_p1)T_LightningFlash)
 		{
 			// lightning was already flashing in this sector
@@ -153,7 +153,7 @@ void P_SpawnLightningFlash(sector_t *sector)
 
 	P_AddThinker(THINK_MAIN, &flash->thinker);
 
-	flash->thinker.function.acp1 = (actionf_p1)T_LightningFlash;
+	flash->thinker.function = (actionf_p1)T_LightningFlash;
 	flash->sector = sector;
 	flash->maxlight = 255;
 	flash->minlight = minlight;
@@ -215,7 +215,7 @@ strobe_t *P_SpawnAdjustableStrobeFlash(sector_t *sector, INT16 lighta, INT16 lig
 	flash->sector = sector;
 	flash->darktime = darktime;
 	flash->brighttime = brighttime;
-	flash->thinker.function.acp1 = (actionf_p1)T_StrobeFlash;
+	flash->thinker.function = (actionf_p1)T_StrobeFlash;
 	flash->maxlight = max(lighta, lightb);
 	flash->minlight = min(lighta, lightb);
 
@@ -285,7 +285,7 @@ glow_t *P_SpawnAdjustableGlowingLight(sector_t *sector, INT16 lighta, INT16 ligh
 	g->sector = sector;
 	g->minlight = min(lighta, lightb);
 	g->maxlight = max(lighta, lightb);
-	g->thinker.function.acp1 = (actionf_p1)T_Glow;
+	g->thinker.function = (actionf_p1)T_Glow;
 	g->direction = 1;
 	g->speed = (INT16)(length/4);
 	if (g->speed > (g->maxlight - g->minlight)/2) // don't make it ridiculous speed
@@ -333,7 +333,7 @@ void P_FadeLightBySector(sector_t *sector, INT32 destvalue, INT32 speed, boolean
 	}
 
 	ll = Z_Calloc(sizeof (*ll), PU_LEVSPEC, NULL);
-	ll->thinker.function.acp1 = (actionf_p1)T_LightFade;
+	ll->thinker.function = (actionf_p1)T_LightFade;
 	sector->lightingdata = ll; // set it to the lightlevel_t
 
 	P_AddThinker(THINK_MAIN, &ll->thinker); // add thinker
@@ -368,7 +368,7 @@ void P_FadeLight(INT16 tag, INT32 destvalue, INT32 speed, boolean ticbased, bool
 	{
 		if (!force && ticbased // always let speed fader execute
 			&& sectors[i].lightingdata
-			&& ((lightlevel_t*)sectors[i].lightingdata)->thinker.function.acp1 == (actionf_p1)T_LightFade)
+			&& ((lightlevel_t*)sectors[i].lightingdata)->thinker.function == (actionf_p1)T_LightFade)
 			// && ((lightlevel_t*)sectors[i].lightingdata)->timer > 2)
 		{
 			CONS_Debug(DBG_GAMELOGIC, "Line type 420 Executor: Fade light thinker already exists, timer: %d\n", ((lightlevel_t*)sectors[i].lightingdata)->timer);
diff --git a/src/p_local.h b/src/p_local.h
index 54be8014e..2e69088ee 100644
--- a/src/p_local.h
+++ b/src/p_local.h
@@ -335,7 +335,7 @@ void P_SceneryThinker(mobj_t *mobj);
 // To test it in Lua, check mobj.valid
 FUNCINLINE static ATTRINLINE boolean P_MobjWasRemoved(const mobj_t *mobj)
 {
-	return mobj == NULL || mobj->thinker.function.acp1 != (actionf_p1)P_MobjThinker;
+	return mobj == NULL || mobj->thinker.function != (actionf_p1)P_MobjThinker;
 }
 
 fixed_t P_MobjFloorZ(const mobj_t *mobj, const sector_t *sector, const sector_t *boundsec, fixed_t x, fixed_t y, const line_t *line, boolean lowest, boolean perfect);
diff --git a/src/p_map.c b/src/p_map.c
index c5b3407e6..35165999f 100644
--- a/src/p_map.c
+++ b/src/p_map.c
@@ -3819,7 +3819,7 @@ static boolean PIT_ChangeSector(mobj_t *thing, boolean realcrush)
 
 						for (think = thlist[THINK_MAIN].next; think != &thlist[THINK_MAIN]; think = think->next)
 						{
-							if (think->function.acp1 != (actionf_p1)T_StartCrumble)
+							if (think->function != (actionf_p1)T_StartCrumble)
 								continue;
 
 							crumbler = (crumble_t *)think;
diff --git a/src/p_mobj.c b/src/p_mobj.c
index 7da13db4f..7a3ce36e3 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -96,7 +96,7 @@ void P_RunCachedActions(void)
 		var2 = states[ac->statenum].var2;
 		astate = &states[ac->statenum];
 		if (ac->mobj && !P_MobjWasRemoved(ac->mobj)) // just in case...
-			states[ac->statenum].action.acp1(ac->mobj);
+			states[ac->statenum].action(ac->mobj);
 		next = ac->next;
 		Z_Free(ac);
 	}
@@ -116,7 +116,7 @@ void P_AddCachedAction(mobj_t *mobj, INT32 statenum)
 static inline INT32 randomframe (mobj_t *mobj, INT32 n)
 {
 	// Only mobj thinkers should use synced RNG
-	if (mobj->thinker.function.acp1 == (actionf_p1)P_MobjThinker)
+	if (mobj->thinker.function == (actionf_p1)P_MobjThinker)
 		return P_RandomKey(n);
 	else
 		return M_RandomKey(n);
@@ -387,12 +387,12 @@ boolean P_SetPlayerMobjState(mobj_t *mobj, statenum_t state)
 		// Modified handling.
 		// Call action functions when the state is set
 
-		if (st->action.acp1)
+		if (st->action)
 		{
 			var1 = st->var1;
 			var2 = st->var2;
 			astate = st;
-			st->action.acp1(mobj);
+			st->action(mobj);
 
 			// woah. a player was removed by an action.
 			// this sounds like a VERY BAD THING, but there's nothing we can do now...
@@ -511,12 +511,12 @@ boolean P_SetMobjState(mobj_t *mobj, statenum_t state)
 		// Modified handling.
 		// Call action functions when the state is set
 
-		if (st->action.acp1)
+		if (st->action)
 		{
 			var1 = st->var1;
 			var2 = st->var2;
 			astate = st;
-			st->action.acp1(mobj);
+			st->action(mobj);
 			if (P_MobjWasRemoved(mobj))
 				return false;
 		}
@@ -3658,7 +3658,7 @@ boolean P_CameraThinker(player_t *player, camera_t *thiscam, boolean resetcalled
 		{
 			mobj_t dummy;
 
-			dummy.thinker.function.acp1 = (actionf_p1)P_MobjThinker;
+			dummy.thinker.function = (actionf_p1)P_MobjThinker;
 			dummy.subsector = thiscam->subsector;
 			dummy.x = thiscam->x;
 			dummy.y = thiscam->y;
@@ -4612,7 +4612,7 @@ static void P_Boss3Thinker(mobj_t *mobj)
 			// this can happen if the boss was hurt earlier than expected
 			for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 			{
-				if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+				if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 					continue;
 
 				mo2 = (mobj_t *)th;
@@ -4703,7 +4703,7 @@ static void P_Boss3Thinker(mobj_t *mobj)
 		// the number
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 				continue;
 
 			mo2 = (mobj_t *)th;
@@ -5330,7 +5330,7 @@ static void P_Boss7Thinker(mobj_t *mobj)
 				// Find waypoint he is closest to
 				for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 				{
-					if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+					if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 						continue;
 
 					mo2 = (mobj_t *)th;
@@ -5385,7 +5385,7 @@ static void P_Boss7Thinker(mobj_t *mobj)
 		// the waypoint to use
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 				continue;
 
 			mo2 = (mobj_t *)th;
@@ -5510,7 +5510,7 @@ static void P_Boss9Thinker(mobj_t *mobj)
 		// Build a hoop linked list of 'em!
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 				continue;
 
 			mo2 = (mobj_t *)th;
@@ -5965,7 +5965,7 @@ mobj_t *P_GetClosestAxis(mobj_t *source)
 	// scan the thinkers to find the closest axis point
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo2 = (mobj_t *)th;
@@ -10302,13 +10302,13 @@ static void P_FiringThink(mobj_t *mobj)
 	if (mobj->health <= 0)
 		return;
 
-	if (mobj->state->action.acp1 == (actionf_p1)A_Boss1Laser)
+	if (mobj->state->action == (actionf_p1)A_Boss1Laser)
 	{
 		if (mobj->state->tics > 1)
 		{
 			var1 = mobj->state->var1;
 			var2 = mobj->state->var2 & 65535;
-			mobj->state->action.acp1(mobj);
+			mobj->state->action(mobj);
 		}
 	}
 	else if (leveltime & 1) // Fire mode
@@ -11151,7 +11151,7 @@ mobj_t *P_SpawnMobj(fixed_t x, fixed_t y, fixed_t z, mobjtype_t type)
 	mobj = P_AllocateMobj();
 
 	// this is officially a mobj, declared as soon as possible.
-	mobj->thinker.function.acp1 = (actionf_p1)P_MobjThinker;
+	mobj->thinker.function = (actionf_p1)P_MobjThinker;
 	mobj->type = type;
 	mobj->info = info;
 
@@ -11310,7 +11310,7 @@ mobj_t *P_SpawnMobj(fixed_t x, fixed_t y, fixed_t z, mobjtype_t type)
 					ball->threshold = ball->radius + mobj->radius + FixedMul(ball->info->painchance, ball->scale);
 
 					var1 = ball->state->var1, var2 = ball->state->var2;
-					ball->state->action.acp1(ball);
+					ball->state->action(ball);
 				}
 			}
 			break;
@@ -11635,7 +11635,7 @@ mobj_t *P_SpawnMobj(fixed_t x, fixed_t y, fixed_t z, mobjtype_t type)
 	}
 
 	// Call action functions when the state is set
-	if (st->action.acp1 && (mobj->flags & MF_RUNSPAWNFUNC))
+	if (st->action && (mobj->flags & MF_RUNSPAWNFUNC))
 	{
 		if (levelloading == true)
 		{
@@ -11650,7 +11650,7 @@ mobj_t *P_SpawnMobj(fixed_t x, fixed_t y, fixed_t z, mobjtype_t type)
 			var1 = st->var1;
 			var2 = st->var2;
 			astate = st;
-			st->action.acp1(mobj);
+			st->action(mobj);
 			// DANGER! This can cause P_SpawnMobj to return NULL!
 			// Avoid using MF_RUNSPAWNFUNC on mobjs whose spawn state expects target or tracer to already be set!
 			if (P_MobjWasRemoved(mobj))
@@ -11709,7 +11709,7 @@ static precipmobj_t *P_SpawnPrecipMobj(fixed_t x, fixed_t y, fixed_t z, mobjtype
 
 	start_z = mobj->floorz;
 
-	mobj->thinker.function.acp1 = (actionf_p1)P_NullPrecipThinker;
+	mobj->thinker.function = (actionf_p1)P_NullPrecipThinker;
 	P_AddThinker(THINK_PRECIP, &mobj->thinker);
 
 	P_CalculatePrecipFloor(mobj);
@@ -11768,9 +11768,9 @@ void P_RemoveMobj(mobj_t *mobj)
 	if (P_MobjWasRemoved(mobj))
 		return; // something already removing this mobj.
 
-	mobj->thinker.function.acp1 = (actionf_p1)P_RemoveThinkerDelayed; // shh. no recursing.
+	mobj->thinker.function = (actionf_p1)P_RemoveThinkerDelayed; // shh. no recursing.
 	LUA_HookMobj(mobj, MOBJ_HOOK(MobjRemoved));
-	mobj->thinker.function.acp1 = (actionf_p1)P_MobjThinker; // needed for P_UnsetThingPosition, etc. to work.
+	mobj->thinker.function = (actionf_p1)P_MobjThinker; // needed for P_UnsetThingPosition, etc. to work.
 
 	// Rings only, please!
 	if (mobj->spawnpoint &&
@@ -11928,7 +11928,7 @@ void P_FreePrecipMobj(precipmobj_t *mobj)
 // Clearing out stuff for savegames
 void P_RemoveSavegameMobj(mobj_t *mobj)
 {
-	if (((thinker_t *)mobj)->function.acp1 == (actionf_p1)P_NullPrecipThinker)
+	if (((thinker_t *)mobj)->function == (actionf_p1)P_NullPrecipThinker)
 	{
 		// unlink from sector and block lists
 		P_UnsetPrecipThingPosition((precipmobj_t *)mobj);
@@ -13340,7 +13340,7 @@ static boolean P_MapAlreadyHasStarPost(mobj_t *mobj)
 
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo2 = (mobj_t *)th;
diff --git a/src/p_polyobj.c b/src/p_polyobj.c
index f161ca833..f5f0305a6 100644
--- a/src/p_polyobj.c
+++ b/src/p_polyobj.c
@@ -1314,7 +1314,7 @@ void Polyobj_InitLevel(void)
 	// the mobj_t pointers on a queue for use below.
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo = (mobj_t *)th;
@@ -2030,7 +2030,7 @@ boolean EV_DoPolyObjRotate(polyrotdata_t *prdata)
 
 	// create a new thinker
 	th = Z_Malloc(sizeof(polyrotate_t), PU_LEVSPEC, NULL);
-	th->thinker.function.acp1 = (actionf_p1)T_PolyObjRotate;
+	th->thinker.function = (actionf_p1)T_PolyObjRotate;
 	P_AddThinker(THINK_POLYOBJ, &th->thinker);
 	po->thinker = &th->thinker;
 
@@ -2102,7 +2102,7 @@ boolean EV_DoPolyObjMove(polymovedata_t *pmdata)
 
 	// create a new thinker
 	th = Z_Malloc(sizeof(polymove_t), PU_LEVSPEC, NULL);
-	th->thinker.function.acp1 = (actionf_p1)T_PolyObjMove;
+	th->thinker.function = (actionf_p1)T_PolyObjMove;
 	P_AddThinker(THINK_POLYOBJ, &th->thinker);
 	po->thinker = &th->thinker;
 
@@ -2164,7 +2164,7 @@ boolean EV_DoPolyObjWaypoint(polywaypointdata_t *pwdata)
 
 	// create a new thinker
 	th = Z_Malloc(sizeof(polywaypoint_t), PU_LEVSPEC, NULL);
-	th->thinker.function.acp1 = (actionf_p1)T_PolyObjWaypoint;
+	th->thinker.function = (actionf_p1)T_PolyObjWaypoint;
 	P_AddThinker(THINK_POLYOBJ, &th->thinker);
 	po->thinker = &th->thinker;
 
@@ -2231,7 +2231,7 @@ static void Polyobj_doSlideDoor(polyobj_t *po, polydoordata_t *doordata)
 
 	// allocate and add a new slide door thinker
 	th = Z_Malloc(sizeof(polyslidedoor_t), PU_LEVSPEC, NULL);
-	th->thinker.function.acp1 = (actionf_p1)T_PolyDoorSlide;
+	th->thinker.function = (actionf_p1)T_PolyDoorSlide;
 	P_AddThinker(THINK_POLYOBJ, &th->thinker);
 
 	// point the polyobject to this thinker
@@ -2282,7 +2282,7 @@ static void Polyobj_doSwingDoor(polyobj_t *po, polydoordata_t *doordata)
 
 	// allocate and add a new swing door thinker
 	th = Z_Malloc(sizeof(polyswingdoor_t), PU_LEVSPEC, NULL);
-	th->thinker.function.acp1 = (actionf_p1)T_PolyDoorSwing;
+	th->thinker.function = (actionf_p1)T_PolyDoorSwing;
 	P_AddThinker(THINK_POLYOBJ, &th->thinker);
 
 	// point the polyobject to this thinker
@@ -2367,7 +2367,7 @@ boolean EV_DoPolyObjDisplace(polydisplacedata_t *prdata)
 
 	// create a new thinker
 	th = Z_Malloc(sizeof(polydisplace_t), PU_LEVSPEC, NULL);
-	th->thinker.function.acp1 = (actionf_p1)T_PolyObjDisplace;
+	th->thinker.function = (actionf_p1)T_PolyObjDisplace;
 	P_AddThinker(THINK_POLYOBJ, &th->thinker);
 	po->thinker = &th->thinker;
 
@@ -2416,7 +2416,7 @@ boolean EV_DoPolyObjRotDisplace(polyrotdisplacedata_t *prdata)
 
 	// create a new thinker
 	th = Z_Malloc(sizeof(polyrotdisplace_t), PU_LEVSPEC, NULL);
-	th->thinker.function.acp1 = (actionf_p1)T_PolyObjRotDisplace;
+	th->thinker.function = (actionf_p1)T_PolyObjRotDisplace;
 	P_AddThinker(THINK_POLYOBJ, &th->thinker);
 	po->thinker = &th->thinker;
 
@@ -2521,7 +2521,7 @@ boolean EV_DoPolyObjFlag(polyflagdata_t *pfdata)
 
 	// create a new thinker
 	th = Z_Malloc(sizeof(polymove_t), PU_LEVSPEC, NULL);
-	th->thinker.function.acp1 = (actionf_p1)T_PolyObjFlag;
+	th->thinker.function = (actionf_p1)T_PolyObjFlag;
 	P_AddThinker(THINK_POLYOBJ, &th->thinker);
 	po->thinker = &th->thinker;
 
@@ -2669,12 +2669,12 @@ boolean EV_DoPolyObjFade(polyfadedata_t *pfdata)
 	if (po->translucency == pfdata->destvalue)
 		return true;
 
-	if (po->thinker && po->thinker->function.acp1 == (actionf_p1)T_PolyObjFade)
+	if (po->thinker && po->thinker->function == (actionf_p1)T_PolyObjFade)
 		P_RemoveThinker(po->thinker);
 
 	// create a new thinker
 	th = Z_Malloc(sizeof(polyfade_t), PU_LEVSPEC, NULL);
-	th->thinker.function.acp1 = (actionf_p1)T_PolyObjFade;
+	th->thinker.function = (actionf_p1)T_PolyObjFade;
 	P_AddThinker(THINK_POLYOBJ, &th->thinker);
 	po->thinker = &th->thinker;
 
diff --git a/src/p_saveg.c b/src/p_saveg.c
index 68d825df2..5d5c01140 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -2082,7 +2082,7 @@ static thinker_t *SyncMobjThinker(savebuffer_t *save, actionf_p1 thinker, thinke
 		mobj = P_AllocateMobj();
 
 	// declare this as a valid mobj as soon as possible.
-	mobj->thinker.function.acp1 = thinker;
+	mobj->thinker.function = thinker;
 
 	// manually link to thinkerlist, since the thinker isn't returned anymore
 	if (!save->write)
@@ -2381,7 +2381,7 @@ static thinker_t *SyncNoEnemiesThinker(savebuffer_t *save, actionf_p1 thinker, t
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 	SYNC(ht->sourceline);
 	return &ht->thinker;
@@ -2397,7 +2397,7 @@ static thinker_t *SyncBounceCheeseThinker(savebuffer_t *save, actionf_p1 thinker
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sourceline);
@@ -2422,7 +2422,7 @@ static thinker_t *SyncContinuousFallThinker(savebuffer_t *save, actionf_p1 think
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sector);
@@ -2449,7 +2449,7 @@ static thinker_t *SyncMarioBlockThinker(savebuffer_t *save, actionf_p1 thinker,
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sector);
@@ -2476,7 +2476,7 @@ static thinker_t *SyncMarioCheckThinker(savebuffer_t *save, actionf_p1 thinker,
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sourceline);
@@ -2494,7 +2494,7 @@ static thinker_t *SyncThwompThinker(savebuffer_t *save, actionf_p1 thinker, thin
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sourceline);
@@ -2526,7 +2526,7 @@ static thinker_t *SyncFloatThinker(savebuffer_t *save, actionf_p1 thinker, think
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sourceline);
@@ -2545,7 +2545,7 @@ static thinker_t *SyncEachTimeThinker(savebuffer_t *save, actionf_p1 thinker, th
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	size_t i;
@@ -2568,7 +2568,7 @@ static thinker_t *SyncRaiseThinker(savebuffer_t *save, actionf_p1 thinker, think
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->tag);
@@ -2592,7 +2592,7 @@ static thinker_t *SyncCeilingThinker(savebuffer_t *save, actionf_p1 thinker, thi
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->type);
@@ -2628,7 +2628,7 @@ static thinker_t *SyncFloormoveThinker(savebuffer_t *save, actionf_p1 thinker, t
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->type);
@@ -2660,7 +2660,7 @@ static thinker_t *SyncLightflashThinker(savebuffer_t *save, actionf_p1 thinker,
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 	SYNC(ht->sector);
 	SYNC(ht->maxlight);
@@ -2680,7 +2680,7 @@ static thinker_t *SyncStrobeThinker(savebuffer_t *save, actionf_p1 thinker, thin
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sector);
@@ -2704,7 +2704,7 @@ static thinker_t *SyncGlowThinker(savebuffer_t *save, actionf_p1 thinker, thinke
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sector);
@@ -2727,7 +2727,7 @@ static thinker_t *SyncFireflickerThinker(savebuffer_t *save, actionf_p1 thinker,
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sector);
@@ -2751,7 +2751,7 @@ static thinker_t *SyncElevatorThinker(savebuffer_t *save, actionf_p1 thinker, th
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->type);
@@ -2788,7 +2788,7 @@ static thinker_t *SyncCrumbleThinker(savebuffer_t *save, actionf_p1 thinker, thi
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sourceline);
@@ -2819,7 +2819,7 @@ static thinker_t *SyncScrollThinker(savebuffer_t *save, actionf_p1 thinker, thin
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->dx);
@@ -2845,7 +2845,7 @@ static thinker_t *SyncFrictionThinker(savebuffer_t *save, actionf_p1 thinker, th
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->friction);
@@ -2866,7 +2866,7 @@ static thinker_t *SyncPusherThinker(savebuffer_t *save, actionf_p1 thinker, thin
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->type);
@@ -2891,7 +2891,7 @@ static thinker_t *SyncLaserThinker(savebuffer_t *save, actionf_p1 thinker, think
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->tag);
@@ -2910,7 +2910,7 @@ static thinker_t *SyncLightlevelThinker(savebuffer_t *save, actionf_p1 thinker,
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sector);
@@ -2934,7 +2934,7 @@ static thinker_t *SyncExecutorThinker(savebuffer_t *save, actionf_p1 thinker, th
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->line);
@@ -2954,7 +2954,7 @@ static thinker_t *SyncDisappearThinker(savebuffer_t *save, actionf_p1 thinker, t
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->appeartime);
@@ -2977,7 +2977,7 @@ static thinker_t *SyncFadeThinker(savebuffer_t *save, actionf_p1 thinker, thinke
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	ht->dest_exc = GetNetColormapFromList(P_SyncUINT32(save, CheckAddNetColormapToList(ht->dest_exc)));
@@ -3030,7 +3030,7 @@ static thinker_t *SyncFadeColormapThinker(savebuffer_t *save, actionf_p1 thinker
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->sector);
@@ -3054,7 +3054,7 @@ static thinker_t *SyncPlaneDisplaceThinker(savebuffer_t *save, actionf_p1 thinke
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->affectee);
@@ -3075,7 +3075,7 @@ static thinker_t *SyncDynamicLineSlopeThinker(savebuffer_t *save, actionf_p1 thi
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->type);
@@ -3096,7 +3096,7 @@ static thinker_t *SyncDynamicVertexSlopeThinker(savebuffer_t *save, actionf_p1 t
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->slope);
@@ -3119,7 +3119,7 @@ static thinker_t *SyncPolyrotatetThinker(savebuffer_t *save, actionf_p1 thinker,
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->polyObjNum);
@@ -3139,7 +3139,7 @@ static thinker_t *SyncPolymoveThinker(savebuffer_t *save, actionf_p1 thinker, th
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->polyObjNum);
@@ -3161,7 +3161,7 @@ static thinker_t *SyncPolywaypointThinker(savebuffer_t *save, actionf_p1 thinker
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->polyObjNum);
@@ -3185,7 +3185,7 @@ static thinker_t *SyncPolyslidedoorThinker(savebuffer_t *save, actionf_p1 thinke
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->polyObjNum);
@@ -3214,7 +3214,7 @@ static thinker_t *SyncPolyswingdoorThinker(savebuffer_t *save, actionf_p1 thinke
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->polyObjNum);
@@ -3238,7 +3238,7 @@ static thinker_t *SyncPolydisplaceThinker(savebuffer_t *save, actionf_p1 thinker
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->polyObjNum);
@@ -3259,7 +3259,7 @@ static thinker_t *SyncPolyrotdisplaceThinker(savebuffer_t *save, actionf_p1 thin
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->polyObjNum);
@@ -3280,7 +3280,7 @@ static thinker_t *SyncPolyfadeThinker(savebuffer_t *save, actionf_p1 thinker, th
 	else
 	{
 		ht = Z_Calloc(sizeof (*ht), PU_LEVSPEC, NULL);
-		ht->thinker.function.acp1 = thinker;
+		ht->thinker.function = thinker;
 	}
 
 	SYNC(ht->polyObjNum);
@@ -3381,7 +3381,7 @@ static void P_NetSyncThinkers(savebuffer_t *save)
 
 				currentthinker->references = 0; // Heinous but this is the only place the assertion in P_UnlinkThinkers is wrong
 
-				if (currentthinker->function.acp1 == (actionf_p1)P_MobjThinker || currentthinker->function.acp1 == (actionf_p1)P_NullPrecipThinker)
+				if (currentthinker->function == (actionf_p1)P_MobjThinker || currentthinker->function == (actionf_p1)P_NullPrecipThinker)
 					P_RemoveSavegameMobj((mobj_t *)currentthinker); // item isn't saved, don't remove it
 				else
 				{
@@ -3425,7 +3425,7 @@ static void P_NetSyncThinkers(savebuffer_t *save)
 					break;
 				}
 
-				acp = th->function.acp1;
+				acp = th->function;
 				if (acp == (actionf_p1)P_NullPrecipThinker || acp == (actionf_p1)P_RemoveThinkerDelayed)
 					continue;
 			}
@@ -3472,7 +3472,7 @@ static void P_NetSyncThinkers(savebuffer_t *save)
 			executor_t *delay;
 			for (currentthinker = thlist[THINK_MAIN].next; currentthinker != &thlist[THINK_MAIN]; currentthinker = currentthinker->next)
 			{
-				if (currentthinker->function.acp1 != (actionf_p1)T_ExecutorDelay)
+				if (currentthinker->function != (actionf_p1)T_ExecutorDelay)
 					continue;
 				delay = (executor_t *)currentthinker;
 				RELINK(&delay->caller);
@@ -3537,7 +3537,7 @@ mobj_t *P_FindNewPosition(UINT32 oldposition)
 
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mobj = (mobj_t *)th;
@@ -3635,7 +3635,7 @@ static void P_RelinkPointers(savebuffer_t *save)
 	for (currentthinker = thlist[THINK_MOBJ].next; currentthinker != &thlist[THINK_MOBJ];
 		currentthinker = currentthinker->next)
 	{
-		if (currentthinker->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (currentthinker->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mobj = (mobj_t *)currentthinker;
@@ -4341,7 +4341,7 @@ void P_SaveNetGame(savebuffer_t *save, boolean resending)
 	{
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 				continue;
 
 			mobj = (mobj_t *)th;
diff --git a/src/p_setup.c b/src/p_setup.c
index 60ae6591c..b9a98b642 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -665,7 +665,7 @@ void P_ReloadRings(void)
 	// scan the thinkers to find rings/spheres/hoops to unset
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo = (mobj_t *)th;
@@ -8185,7 +8185,7 @@ void P_RespawnThings(void)
 
 	for (think = thlist[THINK_MOBJ].next; think != &thlist[THINK_MOBJ]; think = think->next)
 	{
-		if (think->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (think->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 		P_RemoveMobj((mobj_t *)think);
 	}
diff --git a/src/p_slopes.c b/src/p_slopes.c
index 592123632..1b93aafdc 100644
--- a/src/p_slopes.c
+++ b/src/p_slopes.c
@@ -305,7 +305,7 @@ void T_DynamicSlopeVert (dynvertexplanethink_t* th)
 static inline void P_AddDynLineSlopeThinker (pslope_t* slope, dynplanetype_t type, line_t* sourceline, fixed_t extent)
 {
 	dynlineplanethink_t* th = Z_Calloc(sizeof (*th), PU_LEVSPEC, NULL);
-	th->thinker.function.acp1 = (actionf_p1)T_DynamicSlopeLine;
+	th->thinker.function = (actionf_p1)T_DynamicSlopeLine;
 	th->slope = slope;
 	th->type = type;
 	th->sourceline = sourceline;
@@ -321,7 +321,7 @@ static inline void P_AddDynVertexSlopeThinker (pslope_t* slope, const INT16 tags
 	dynvertexplanethink_t* th = Z_Calloc(sizeof (*th), PU_LEVSPEC, NULL);
 	size_t i;
 	INT32 l;
-	th->thinker.function.acp1 = (actionf_p1)T_DynamicSlopeVert;
+	th->thinker.function = (actionf_p1)T_DynamicSlopeVert;
 	th->slope = slope;
 
 	for (i = 0; i < 3; i++) {
diff --git a/src/p_spec.c b/src/p_spec.c
index fc9837b51..28bb027ec 100644
--- a/src/p_spec.c
+++ b/src/p_spec.c
@@ -1025,7 +1025,7 @@ static boolean PolyFade(INT32 *args)
 	// Prevent continuous execs from interfering on an existing fade
 	if (!(args[3] & TMPF_OVERRIDE)
 		&& po->thinker
-		&& po->thinker->function.acp1 == (actionf_p1)T_PolyObjFade)
+		&& po->thinker->function == (actionf_p1)T_PolyObjFade)
 	{
 		CONS_Debug(DBG_POLYOBJ, "Line type 492 Executor: Fade PolyObject thinker already exists\n");
 		return 0;
@@ -1240,7 +1240,7 @@ static void P_AddExecutorDelay(line_t *line, mobj_t *mobj, sector_t *sector)
 
 	e = Z_Calloc(sizeof (*e), PU_LEVSPEC, NULL);
 
-	e->thinker.function.acp1 = (actionf_p1)T_ExecutorDelay;
+	e->thinker.function = (actionf_p1)T_ExecutorDelay;
 	e->line = line;
 	e->sector = sector;
 	e->timer = delay;
@@ -1827,7 +1827,7 @@ void P_SwitchWeather(preciptype_t newWeather)
 		{
 			next = think->next;
 
-			if (think->function.acp1 != (actionf_p1)P_NullPrecipThinker)
+			if (think->function != (actionf_p1)P_NullPrecipThinker)
 				continue; // not a precipmobj thinker
 
 			precipmobj = (precipmobj_t *)think;
@@ -1843,7 +1843,7 @@ void P_SwitchWeather(preciptype_t newWeather)
 
 		for (think = thlist[THINK_PRECIP].next; think != &thlist[THINK_PRECIP]; think = think->next)
 		{
-			if (think->function.acp1 != (actionf_p1)P_NullPrecipThinker)
+			if (think->function != (actionf_p1)P_NullPrecipThinker)
 				continue; // not a precipmobj thinker
 
 			precipmobj = (precipmobj_t *)think;
@@ -3266,7 +3266,7 @@ boolean P_ProcessSpecial(activator_t *activator, INT16 special, INT32 *args, cha
 
 				for (th = thlist[THINK_MAIN].next; th != &thlist[THINK_MAIN]; th = th->next)
 				{
-					if (th->function.acp1 != (actionf_p1)T_Scroll)
+					if (th->function != (actionf_p1)T_Scroll)
 						continue;
 
 					scroller = (scroll_t *)th;
@@ -4223,7 +4223,7 @@ boolean P_ProcessSpecial(activator_t *activator, INT16 special, INT32 *args, cha
 					if (mo2->type != MT_EGGTRAP)
 						continue;
 
-					if (mo2->thinker.function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+					if (mo2->thinker.function == (actionf_p1)P_RemoveThinkerDelayed)
 						continue;
 
 					P_KillMobj(mo2, NULL, mo, DMG_NORMAL);
@@ -4582,7 +4582,7 @@ void P_SetupSignExit(player_t *player)
 	// spin all signposts in the level then.
 	for (think = thlist[THINK_MOBJ].next; think != &thlist[THINK_MOBJ]; think = think->next)
 	{
-		if (think->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (think->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		thing = (mobj_t *)think;
@@ -5070,7 +5070,7 @@ static void P_ProcessEggCapsule(player_t *player, sector_t *sector)
 	// The chimps are my friends.. heeheeheheehehee..... - LouisJM
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 		mo2 = (mobj_t *)th;
 		if (mo2->type != MT_EGGTRAP)
@@ -6327,7 +6327,7 @@ static ffloor_t *P_AddFakeFloor(sector_t *sec, sector_t *sec2, line_t *master, I
 			break;
 
 		// Should this FOF have friction?
-		if(th->function.acp1 == (actionf_p1)T_Friction)
+		if(th->function == (actionf_p1)T_Friction)
 		{
 			f = (friction_t *)th;
 
@@ -6335,7 +6335,7 @@ static ffloor_t *P_AddFakeFloor(sector_t *sec, sector_t *sec2, line_t *master, I
 				Add_Friction(f->friction, f->movefactor, (INT32)(sec-sectors), f->affectee);
 		}
 		// Should this FOF have wind/current/pusher?
-		else if(th->function.acp1 == (actionf_p1)T_Pusher)
+		else if(th->function == (actionf_p1)T_Pusher)
 		{
 			p = (pusher_t *)th;
 
@@ -6470,7 +6470,7 @@ static void P_AddFloatThinker(sector_t *sec, UINT16 tag, line_t *sourceline)
 	floater = Z_Calloc(sizeof (*floater), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &floater->thinker);
 
-	floater->thinker.function.acp1 = (actionf_p1)T_FloatSector;
+	floater->thinker.function = (actionf_p1)T_FloatSector;
 
 	floater->sector = sec;
 	floater->tag = (INT16)tag;
@@ -6501,7 +6501,7 @@ static void P_AddPlaneDisplaceThinker(INT32 type, fixed_t speed, INT32 control,
 	displace = Z_Calloc(sizeof (*displace), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &displace->thinker);
 
-	displace->thinker.function.acp1 = (actionf_p1)T_PlaneDisplace;
+	displace->thinker.function = (actionf_p1)T_PlaneDisplace;
 	displace->affectee = affectee;
 	displace->control = control;
 	displace->last_height = sectors[control].floorheight;
@@ -6531,7 +6531,7 @@ static void P_AddBlockThinker(sector_t *sec, line_t *sourceline)
 	block = Z_Calloc(sizeof (*block), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &block->thinker);
 
-	block->thinker.function.acp1 = (actionf_p1)T_MarioBlockChecker;
+	block->thinker.function = (actionf_p1)T_MarioBlockChecker;
 	block->sourceline = sourceline;
 
 	block->sector = sec;
@@ -6556,7 +6556,7 @@ static void P_AddRaiseThinker(sector_t *sec, INT16 tag, fixed_t speed, fixed_t c
 	raise = Z_Calloc(sizeof (*raise), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &raise->thinker);
 
-	raise->thinker.function.acp1 = (actionf_p1)T_RaiseSector;
+	raise->thinker.function = (actionf_p1)T_RaiseSector;
 
 	raise->tag = tag;
 	raise->sector = sec;
@@ -6582,7 +6582,7 @@ static void P_AddAirbob(sector_t *sec, INT16 tag, fixed_t dist, boolean raise, b
 	airbob = Z_Calloc(sizeof (*airbob), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &airbob->thinker);
 
-	airbob->thinker.function.acp1 = (actionf_p1)T_RaiseSector;
+	airbob->thinker.function = (actionf_p1)T_RaiseSector;
 
 	airbob->tag = tag;
 	airbob->sector = sec;
@@ -6622,7 +6622,7 @@ static inline void P_AddThwompThinker(sector_t *sec, line_t *sourceline, fixed_t
 	thwomp = Z_Calloc(sizeof (*thwomp), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &thwomp->thinker);
 
-	thwomp->thinker.function.acp1 = (actionf_p1)T_ThwompSector;
+	thwomp->thinker.function = (actionf_p1)T_ThwompSector;
 
 	// set up the fields according to the type of elevator action
 	thwomp->sourceline = sourceline;
@@ -6662,7 +6662,7 @@ static inline void P_AddNoEnemiesThinker(line_t *sourceline)
 	nobaddies = Z_Calloc(sizeof (*nobaddies), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &nobaddies->thinker);
 
-	nobaddies->thinker.function.acp1 = (actionf_p1)T_NoEnemiesSector;
+	nobaddies->thinker.function = (actionf_p1)T_NoEnemiesSector;
 
 	nobaddies->sourceline = sourceline;
 }
@@ -6682,7 +6682,7 @@ static void P_AddEachTimeThinker(line_t *sourceline, boolean triggerOnExit)
 	eachtime = Z_Calloc(sizeof (*eachtime), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &eachtime->thinker);
 
-	eachtime->thinker.function.acp1 = (actionf_p1)T_EachTimeThinker;
+	eachtime->thinker.function = (actionf_p1)T_EachTimeThinker;
 
 	eachtime->sourceline = sourceline;
 	eachtime->triggerOnExit = triggerOnExit;
@@ -6706,7 +6706,7 @@ static inline void P_AddCameraScanner(sector_t *sourcesec, sector_t *actionsecto
 	elevator = Z_Calloc(sizeof (*elevator), PU_LEVSPEC, NULL);
 	P_AddThinker(THINK_MAIN, &elevator->thinker);
 
-	elevator->thinker.function.acp1 = (actionf_p1)T_CameraScanner;
+	elevator->thinker.function = (actionf_p1)T_CameraScanner;
 	elevator->type = elevateBounce;
 
 	// set up the fields according to the type of elevator action
@@ -6790,7 +6790,7 @@ static inline void P_AddLaserThinker(INT16 tag, line_t *line, boolean nobosses)
 
 	P_AddThinker(THINK_MAIN, &flash->thinker);
 
-	flash->thinker.function.acp1 = (actionf_p1)T_LaserFlash;
+	flash->thinker.function = (actionf_p1)T_LaserFlash;
 	flash->tag = tag;
 	flash->sourceline = line;
 	flash->nobosses = nobosses;
@@ -7020,9 +7020,9 @@ void P_SpawnSpecials(boolean fromnetsave)
 	// Firstly, find out how many there are in each sector
 	for (th = thlist[THINK_MAIN].next; th != &thlist[THINK_MAIN]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)T_Friction)
+		if (th->function == (actionf_p1)T_Friction)
 			secthinkers[((friction_t *)th)->affectee].count++;
-		else if (th->function.acp1 == (actionf_p1)T_Pusher)
+		else if (th->function == (actionf_p1)T_Pusher)
 			secthinkers[((pusher_t *)th)->affectee].count++;
 	}
 
@@ -7040,9 +7040,9 @@ void P_SpawnSpecials(boolean fromnetsave)
 	{
 		size_t secnum = (size_t)-1;
 
-		if (th->function.acp1 == (actionf_p1)T_Friction)
+		if (th->function == (actionf_p1)T_Friction)
 			secnum = ((friction_t *)th)->affectee;
-		else if (th->function.acp1 == (actionf_p1)T_Pusher)
+		else if (th->function == (actionf_p1)T_Pusher)
 			secnum = ((pusher_t *)th)->affectee;
 
 		if (secnum != (size_t)-1)
@@ -8347,7 +8347,7 @@ static boolean IsSector3DBlock(sector_t* sec)
 static void Add_Scroller(INT32 type, fixed_t dx, fixed_t dy, INT32 control, INT32 affectee, INT32 accel, INT32 exclusive)
 {
 	scroll_t *s = Z_Calloc(sizeof *s, PU_LEVSPEC, NULL);
-	s->thinker.function.acp1 = (actionf_p1)T_Scroll;
+	s->thinker.function = (actionf_p1)T_Scroll;
 	s->type = type;
 	s->dx = dx;
 	s->dy = dy;
@@ -8503,7 +8503,7 @@ static void Add_MasterDisappearer(tic_t appeartime, tic_t disappeartime, tic_t o
 {
 	disappear_t *d = Z_Malloc(sizeof *d, PU_LEVSPEC, NULL);
 
-	d->thinker.function.acp1 = (actionf_p1)T_Disappear;
+	d->thinker.function = (actionf_p1)T_Disappear;
 	d->appeartime = appeartime;
 	d->disappeartime = disappeartime;
 	d->offset = offset;
@@ -8898,7 +8898,7 @@ static void P_AddFakeFloorFader(ffloor_t *rover, size_t sectornum, size_t ffloor
 
 	d = Z_Malloc(sizeof *d, PU_LEVSPEC, NULL);
 
-	d->thinker.function.acp1 = (actionf_p1)T_Fade;
+	d->thinker.function = (actionf_p1)T_Fade;
 	d->rover = rover;
 	d->sectornum = (UINT32)sectornum;
 	d->ffloornum = (UINT32)ffloornum;
@@ -9050,7 +9050,7 @@ static void Add_ColormapFader(sector_t *sector, extracolormap_t *source_exc, ext
 	}
 
 	d = Z_Malloc(sizeof *d, PU_LEVSPEC, NULL);
-	d->thinker.function.acp1 = (actionf_p1)T_FadeColormap;
+	d->thinker.function = (actionf_p1)T_FadeColormap;
 	d->sector = sector;
 	d->source_exc = source_exc;
 	d->dest_exc = dest_exc;
@@ -9174,7 +9174,7 @@ static void Add_Friction(INT32 friction, INT32 movefactor, INT32 affectee, INT32
 {
 	friction_t *f = Z_Calloc(sizeof *f, PU_LEVSPEC, NULL);
 
-	f->thinker.function.acp1 = (actionf_p1)T_Friction;
+	f->thinker.function = (actionf_p1)T_Friction;
 	f->friction = friction;
 	f->movefactor = movefactor;
 	f->affectee = affectee;
@@ -9331,7 +9331,7 @@ static void Add_Pusher(pushertype_e type, fixed_t x_mag, fixed_t y_mag, fixed_t
 {
 	pusher_t *p = Z_Calloc(sizeof *p, PU_LEVSPEC, NULL);
 
-	p->thinker.function.acp1 = (actionf_p1)T_Pusher;
+	p->thinker.function = (actionf_p1)T_Pusher;
 	p->type = type;
 	p->x_mag = x_mag;
 	p->y_mag = y_mag;
diff --git a/src/p_tick.c b/src/p_tick.c
index 0c5a96976..6dd793d9e 100644
--- a/src/p_tick.c
+++ b/src/p_tick.c
@@ -132,7 +132,7 @@ void Command_Numthinkers_f(void)
 	{
 		for (think = thlist[i].next; think != &thlist[i]; think = think->next)
 		{
-			if (think->function.acp1 != action)
+			if (think->function != action)
 				continue;
 
 			count++;
@@ -170,7 +170,7 @@ void Command_CountMobjs_f(void)
 
 			for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 			{
-				if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+				if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 					continue;
 
 				if (((mobj_t *)th)->type == i)
@@ -190,7 +190,7 @@ void Command_CountMobjs_f(void)
 
 		for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 		{
-			if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+			if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 				continue;
 
 			if (((mobj_t *)th)->type == i)
@@ -262,7 +262,7 @@ void P_AddThinker(const thinklistnum_t n, thinker_t *thinker)
 #ifdef PARANOIA
 static const char *MobjTypeName(const mobj_t *mobj)
 {
-	actionf_p1 p1 = mobj->thinker.function.acp1;
+	actionf_p1 p1 = mobj->thinker.function;
 
 	if (p1 == (actionf_p1)P_MobjThinker)
 	{
@@ -281,7 +281,7 @@ static const char *MobjTypeName(const mobj_t *mobj)
 
 static const char *MobjThinkerName(const mobj_t *mobj)
 {
-	actionf_p1 p1 = mobj->thinker.function.acp1;
+	actionf_p1 p1 = mobj->thinker.function;
 
 	if (p1 == (actionf_p1)P_MobjThinker)
 	{
@@ -397,7 +397,7 @@ void P_UnlinkThinker(thinker_t *thinker)
 void P_RemoveThinker(thinker_t *thinker)
 {
 	LUA_InvalidateUserdata(thinker);
-	thinker->function.acp1 = (actionf_p1)P_RemoveThinkerDelayed;
+	thinker->function = (actionf_p1)P_RemoveThinkerDelayed;
 }
 
 /*
@@ -486,9 +486,9 @@ static void P_RunThinkers(void)
 		for (currentthinker = thlist[i].next; currentthinker != &thlist[i]; currentthinker = currentthinker->next)
 		{
 #ifdef PARANOIA
-			I_Assert(currentthinker->function.acp1 != NULL);
+			I_Assert(currentthinker->function != NULL);
 #endif
-			currentthinker->function.acp1(currentthinker);
+			currentthinker->function(currentthinker);
 		}
 		ps_thlist_times[i] = I_GetPreciseTime() - ps_thlist_times[i];
 	}
diff --git a/src/p_user.c b/src/p_user.c
index d13c794a1..0f20413d3 100644
--- a/src/p_user.c
+++ b/src/p_user.c
@@ -2465,7 +2465,7 @@ void P_NukeEnemies(mobj_t *inflictor, mobj_t *source, fixed_t radius)
 
 	for (think = thlist[THINK_MOBJ].next; think != &thlist[THINK_MOBJ]; think = think->next)
 	{
-		if (think->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (think->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mo = (mobj_t *)think;
@@ -3620,7 +3620,7 @@ static mobj_t *P_GetAxis(INT32 num)
 
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 == (actionf_p1)P_RemoveThinkerDelayed)
+		if (th->function == (actionf_p1)P_RemoveThinkerDelayed)
 			continue;
 
 		mobj = (mobj_t *)th;
diff --git a/src/r_data.c b/src/r_data.c
index 0e9820e58..58c140214 100644
--- a/src/r_data.c
+++ b/src/r_data.c
@@ -1326,7 +1326,7 @@ static void R_PrecacheLevelSprites(void)
 
 	for (th = thlist[THINK_MOBJ].next; th != &thlist[THINK_MOBJ]; th = th->next)
 	{
-		if (th->function.acp1 != (actionf_p1)P_MobjThinker)
+		if (th->function != (actionf_p1)P_MobjThinker)
 			continue;
 
 		spritepresent[((mobj_t *)th)->sprite] = 1;