diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index c54985e67..3f002df34 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,4 +1,15 @@
 March 1, 2008 (Changes by Graf Zahl)
+- fixed: A_CountdownArg used 0 based indices although all uses of it assumed
+  1-based.
+- added MF5_DONTRIP flag.
+- added CheckActorFloorTexture, CheckActorCeilingTexture and
+  GetActorLightLevel ACS functions.
+- added IF_ADDITIVETIME flag to create powerups that add their duration
+  to the one of the currently active item of the same type.
+- fixed: bouncecount wasn't decreased when bouncing on walls.
+- Added MF5_ALWAYSRESPAWN and MF5_NEVERRESPAWN flags that selectively
+  enable or disable monster respawning regardless of skill setting.
+- Prettified deprecated flag handling.
 - Fixed: When starting a level while the music has been paused S_Start has 
   to stop the old music so the new one always starts at the beginning.
 - Fixed:: AActor::master was not serialized.
diff --git a/src/actor.h b/src/actor.h
index 99a642a6d..a08ea5d68 100644
--- a/src/actor.h
+++ b/src/actor.h
@@ -294,6 +294,10 @@ enum
 	MF5_NOPAIN			= 0x00004000,	// If set the pain state won't be entered
 	MF5_ALWAYSFAST		= 0x00008000,	// always uses 'fast' attacking logic
 	MF5_NEVERFAST		= 0x00010000,	// never uses 'fast' attacking logic
+	MF5_ALWAYSRESPAWN	= 0x00020000,	// always respawns, regardless of skill setting
+	MF5_NEVERRESPAWN	= 0x00040000,	// never respawns, regardless of skill setting
+	MF5_DONTRIP			= 0x00080000,	// Ripping projectiles explode when hittin this actor
+
 
 // --- mobj.renderflags ---
 
diff --git a/src/g_shared/a_artifacts.cpp b/src/g_shared/a_artifacts.cpp
index 2783c74c8..ff64b44f4 100644
--- a/src/g_shared/a_artifacts.cpp
+++ b/src/g_shared/a_artifacts.cpp
@@ -58,7 +58,7 @@ bool APowerupGiver::Use (bool pickup)
 		power->mode = mode;
 	}
 
-	power->ItemFlags |= ItemFlags & IF_ALWAYSPICKUP;
+	power->ItemFlags |= ItemFlags & (IF_ALWAYSPICKUP|IF_ADDITIVETIME);
 	if (power->TryPickup (Owner))
 	{
 		return true;
@@ -259,7 +259,12 @@ bool APowerup::HandlePickup (AInventory *item)
 		}
 		// Only increase the EffectTics, not decrease it.
 		// Color also gets transferred only when the new item has an effect.
-		if (power->EffectTics > EffectTics)
+		if (power->ItemFlags & IF_ADDITIVETIME) 
+		{
+			EffectTics += power->EffectTics;
+			BlendColor = power->BlendColor;
+		}
+		else if (power->EffectTics > EffectTics)
 		{
 			EffectTics = power->EffectTics;
 			BlendColor = power->BlendColor;
diff --git a/src/g_shared/a_pickups.h b/src/g_shared/a_pickups.h
index 0acf90170..3ceaa9a0a 100644
--- a/src/g_shared/a_pickups.h
+++ b/src/g_shared/a_pickups.h
@@ -90,7 +90,7 @@ enum
 	IF_INVBAR			= 1<<6,		// Item appears in the inventory bar
 	IF_HUBPOWER			= 1<<7,		// Powerup is kept when moving in a hub
 	IF_INTERHUBSTRIP	= 1<<8,		// Item is removed when travelling between hubs
-	//IF_PICKUPFLASH		= 1<<9,	// superseded by 'PickupFlash' property.
+	IF_ADDITIVETIME		= 1<<9,		// when picked up while another item is active, time is added instead of replaced.
 	IF_ALWAYSPICKUP		= 1<<10,	// For IF_AUTOACTIVATE, MaxAmount=0 items: Always "pick up", even if it doesn't do anything
 	IF_FANCYPICKUPSOUND	= 1<<11,	// Play pickup sound in "surround" mode
 	IF_BIGPOWERUP		= 1<<12,	// Affected by RESPAWN_SUPER dmflag
diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index 58b2f2a67..503fd7def 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -5256,6 +5256,41 @@ int DLevelScript::RunScript ()
 			STACK(3) = P_Thing_Damage (STACK(3), activator, STACK(2), FName(FBehavior::StaticLookupString(STACK(1))));
 			sp -= 2;
 			break;
+
+		case PCD_CHECKACTORCEILINGTEXTURE:
+		{
+			AActor *actor = SingleActorFromTID(STACK(2), activator);
+			if (actor != NULL)
+			{
+				FTexture *tex = TexMan.FindTexture(FBehavior::StaticLookupString(STACK(1)));
+				STACK(2) = (tex == TexMan[actor->Sector->ceilingpic]);
+			}
+			else STACK(2)=0;
+			sp--;
+			break;
+		}
+
+		case PCD_CHECKACTORFLOORTEXTURE:
+		{
+			AActor *actor = SingleActorFromTID(STACK(2), activator);
+			if (actor != NULL)
+			{
+				FTexture *tex = TexMan.FindTexture(FBehavior::StaticLookupString(STACK(1)));
+				STACK(2) = (tex == TexMan[actor->Sector->floorpic]);
+			}
+			else STACK(2)=0;
+			sp--;
+			break;
+		}
+
+		case PCD_GETACTORLIGHTLEVEL:
+			AActor *actor = SingleActorFromTID(STACK(1), activator);
+			if (actor != NULL)
+			{
+				STACK(1) = actor->Sector->lightlevel;
+			}
+			else STACK(1)=0;
+			break;
 		}
 	}
 
diff --git a/src/p_acs.h b/src/p_acs.h
index 3d63b90e6..de0b0ea98 100644
--- a/src/p_acs.h
+++ b/src/p_acs.h
@@ -544,6 +544,9 @@ public:
 		PCD_THINGDAMAGE2,
 		PCD_USEINVENTORY,
 		PCD_USEACTORINVENTORY,
+		PCD_CHECKACTORCEILINGTEXTURE,
+		PCD_CHECKACTORFLOORTEXTURE,
+/*340*/	PCD_GETACTORLIGHTLEVEL,
 
 		PCODE_COMMAND_COUNT
 	};
diff --git a/src/p_map.cpp b/src/p_map.cpp
index 4453c5cd6..704eae957 100644
--- a/src/p_map.cpp
+++ b/src/p_map.cpp
@@ -1019,7 +1019,7 @@ bool PIT_CheckThing (AActor *thing)
 		{
 			return true;
 		}
-		if (DoRipping)
+		if (DoRipping && !(thing->flags5 & MF5_DONTRIP))
 		{
 			if (LastRipped != thing)
 			{
@@ -2475,6 +2475,13 @@ bool P_BounceWall (AActor *mo)
 		return true;
 	}
 
+	// The amount of bounces is limited
+	if (mo->bouncecount>0 && --mo->bouncecount==0)
+	{
+		P_ExplodeMissile(mo, NULL, NULL);
+		return true;
+	}
+
 	side = P_PointOnLineSide (mo->x, mo->y, line);
 	lineangle = R_PointToAngle2 (0, 0, line->dx, line->dy);
 	if (side == 1)
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 41a9b5a51..c3fa26d96 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -2963,8 +2963,15 @@ void AActor::Tick ()
 	{
 		int respawn_monsters = G_SkillProperty(SKILLP_Respawn);
 		// check for nightmare respawn
-		if (!respawn_monsters || !(flags3 & MF3_ISMONSTER) || (flags2 & MF2_DORMANT))
-			return;
+		if (!(flags5 & MF5_ALWAYSRESPAWN))
+		{
+			if (!respawn_monsters || !(flags3 & MF3_ISMONSTER) || (flags2 & MF2_DORMANT) || (flags5 & MF5_NEVERRESPAWN))
+				return;
+
+			int limit = G_SkillProperty (SKILLP_RespawnLimit);
+			if (limit > 0 && skillrespawncount >= limit)
+				return;
+		}
 
 		movecount++;
 
@@ -2977,9 +2984,6 @@ void AActor::Tick ()
 		if (pr_nightmarerespawn() > 4)
 			return;
 
-		if (G_SkillProperty (SKILLP_RespawnLimit) && (this)->skillrespawncount >= G_SkillProperty (SKILLP_RespawnLimit))
-			return;
-
 		P_NightmareRespawn (this);
 	}
 }
@@ -4405,7 +4409,7 @@ bool P_CheckMissileSpawn (AActor* th)
 	if (!P_TryMove (th, th->x, th->y, false))
 	{
 		// [RH] Don't explode ripping missiles that spawn inside something
-		if (BlockingMobj == NULL || !(th->flags2 & MF2_RIP))
+		if (BlockingMobj == NULL || !(th->flags2 & MF2_RIP) || (BlockingMobj->flags5 & MF5_DONTRIP))
 		{
 			// If this is a monster spawned by A_CustomMissile subtract it from the counter.
 			if (th->CountsAsKill())
diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index 2d63010a2..e4c49b32e 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -1915,9 +1915,9 @@ void A_CountdownArg(AActor * self)
 {
 	int index=CheckIndex(1);
 	if (index<0) return;
-	index = EvalExpressionI (StateParameters[index], self);
+	index = EvalExpressionI (StateParameters[index], self) - 1;
 
-	if (index<=0 || index>5) return;
+	if (index<0 || index>=5) return;
 	if (!self->args[index]--)
 	{
 		if (self->flags&MF_MISSILE)
diff --git a/src/thingdef/thingdef_properties.cpp b/src/thingdef/thingdef_properties.cpp
index 8c0be8576..093068a24 100644
--- a/src/thingdef/thingdef_properties.cpp
+++ b/src/thingdef/thingdef_properties.cpp
@@ -79,7 +79,7 @@
 // [RH] Keep GCC quiet by not using offsetof on Actor types.
 #define DEFINE_FLAG(prefix, name, type, variable) { prefix##_##name, #name, (int)(size_t)&((type*)1)->variable - 1 }
 #define DEFINE_FLAG2(symbol, name, type, variable) { symbol, #name, (int)(size_t)&((type*)1)->variable - 1 }
-#define DEFINE_DEPRECATED_FLAG(name, type, index) { index, #name, -1 }
+#define DEFINE_DEPRECATED_FLAG(name, type) { DEPF_##name, #name, -1 }
 
 struct flagdef
 {
@@ -88,6 +88,15 @@ struct flagdef
 	int structoffset;
 };
 
+enum 
+{
+	DEPF_FIREDAMAGE,
+	DEPF_ICEDAMAGE,
+	DEPF_LOWGRAVITY,
+	DEPF_LONGMELEERANGE,
+	DEPF_SHORTMISSILERANGE,
+	DEPF_PICKUPFLASH
+};
 
 static flagdef ActorFlags[]=
 {
@@ -221,6 +230,9 @@ static flagdef ActorFlags[]=
 	DEFINE_FLAG(MF5, NOPAIN, AActor, flags5),
 	DEFINE_FLAG(MF5, ALWAYSFAST, AActor, flags5),
 	DEFINE_FLAG(MF5, NEVERFAST, AActor, flags5),
+	DEFINE_FLAG(MF5, ALWAYSRESPAWN, AActor, flags5),
+	DEFINE_FLAG(MF5, NEVERRESPAWN, AActor, flags5),
+	DEFINE_FLAG(MF5, DONTRIP, AActor, flags5),
 
 	// Effect flags
 	DEFINE_FLAG(FX, VISIBILITYPULSE, AActor, effects),
@@ -231,11 +243,11 @@ static flagdef ActorFlags[]=
 	DEFINE_FLAG(RF, FORCEXYBILLBOARD, AActor, renderflags),
 
 	// Deprecated flags. Handling must be performed in HandleDeprecatedFlags
-	DEFINE_DEPRECATED_FLAG(FIREDAMAGE, AActor, 0),
-	DEFINE_DEPRECATED_FLAG(ICEDAMAGE, AActor, 1),
-	DEFINE_DEPRECATED_FLAG(LOWGRAVITY, AActor, 2),
-	DEFINE_DEPRECATED_FLAG(SHORTMISSILERANGE, AActor, 3),
-	DEFINE_DEPRECATED_FLAG(LONGMELEERANGE, AActor, 4),
+	DEFINE_DEPRECATED_FLAG(FIREDAMAGE, AActor),
+	DEFINE_DEPRECATED_FLAG(ICEDAMAGE, AActor),
+	DEFINE_DEPRECATED_FLAG(LOWGRAVITY, AActor),
+	DEFINE_DEPRECATED_FLAG(SHORTMISSILERANGE, AActor),
+	DEFINE_DEPRECATED_FLAG(LONGMELEERANGE, AActor),
 };
 
 static flagdef InventoryFlags[] =
@@ -252,8 +264,9 @@ static flagdef InventoryFlags[] =
 	DEFINE_FLAG(IF, BIGPOWERUP, AInventory, ItemFlags),
 	DEFINE_FLAG(IF, KEEPDEPLETED, AInventory, ItemFlags),
 	DEFINE_FLAG(IF, IGNORESKILL, AInventory, ItemFlags),
+	DEFINE_FLAG(IF, ADDITIVETIME, AInventory, ItemFlags),
 
-	DEFINE_DEPRECATED_FLAG(PICKUPFLASH, AInventory, 5),
+	DEFINE_DEPRECATED_FLAG(PICKUPFLASH, AInventory),
 
 };
 
@@ -385,22 +398,22 @@ static void HandleDeprecatedFlags(AActor *defaults, bool set, int index)
 {
 	switch (index)
 	{
-	case 0:	// FIREDAMAGE
+	case DEPF_FIREDAMAGE:
 		defaults->DamageType = set? NAME_Fire : NAME_None;
 		break;
-	case 1:	// ICEDAMAGE
+	case DEPF_ICEDAMAGE:
 		defaults->DamageType = set? NAME_Ice : NAME_None;
 		break;
-	case 2:	// LOWGRAVITY
+	case DEPF_LOWGRAVITY:
 		defaults->gravity = set? FRACUNIT/8 : FRACUNIT;
 		break;
-	case 3:	// SHORTMISSILERANGE
+	case DEPF_SHORTMISSILERANGE:
 		defaults->maxtargetrange = set? 896*FRACUNIT : 0;
 		break;
-	case 4:	// LONGMELEERANGE
+	case DEPF_LONGMELEERANGE:
 		defaults->meleethreshold = set? 196*FRACUNIT : 0;
 		break;
-	case 5:	// INVENTORY.PICKUPFLASH
+	case DEPF_PICKUPFLASH:
 		if (set)
 		{
 			static_cast<AInventory*>(defaults)->PickupFlash = fuglyname("PickupFlash");