diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index 00e20695d..8c7a5fc0c 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,4 +1,17 @@
 July 12, 2006
+- Changed decorate replacement to be opt-in instead of opt-out. This allows for
+  greater flexibility in what can be replaced (replaced actors need not be ancestors
+  of actors that replace them) at the expense of not having universal actor
+  replacement. Instances where replacements work:
+   - Line specials that spawn things (Thing_Spawn and related)
+   - ACS spawning commands (SpawnSpot and the like)
+   - Spawning mapthings at level load time in P_SpawnMapThing()
+   - Spawning items off of dead dudes in P_DropItem()
+   - The A_SpawnItem decorate function
+   - The summon and summonfriend console commands
+   - ThingCount will count both original actors and their replacements as the same
+     things.
+  TBD: Should the ACS inventory functions use replacements too, or not?
 - Fixed: The game would crash after informing you of a duplicate class registration
   because PClass::CreateDerivedClass() did not initialize everything before calling
   InsertIntoHash().
diff --git a/src/d_net.cpp b/src/d_net.cpp
index 0e581b4b1..36860135d 100644
--- a/src/d_net.cpp
+++ b/src/d_net.cpp
@@ -2112,6 +2112,9 @@ void Net_DoCommand (int type, byte **stream, int player)
 			typeinfo = PClass::FindClass (s);
 			if (typeinfo != NULL && typeinfo->ActorInfo != NULL)
 			{
+				// Handle decorate replacements.
+				typeinfo = typeinfo->ActorInfo->GetReplacement()->Class;
+
 				AActor *source = players[player].mo;
 				if (source != NULL)
 				{
diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index 96a87cdd3..007d97c9e 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -1680,6 +1680,7 @@ int DLevelScript::ThingCount (int type, int stringid, int tid)
 	AActor *actor;
 	const PClass *kind;
 	int count = 0;
+	bool replacemented = false;
 
 	if (type >= MAX_SPAWNABLES)
 	{
@@ -1698,7 +1699,7 @@ int DLevelScript::ThingCount (int type, int stringid, int tid)
 			return 0;
 	
 		kind = PClass::FindClass (type_name);
-		if (kind == NULL)
+		if (kind == NULL || kind->ActorInfo == NULL)
 			return 0;
 	
 	}
@@ -1706,7 +1707,8 @@ int DLevelScript::ThingCount (int type, int stringid, int tid)
 	{
 		kind = NULL;
 	}
-	
+
+do_count:
 	if (tid)
 	{
 		FActorIterator iterator (tid);
@@ -1741,6 +1743,17 @@ int DLevelScript::ThingCount (int type, int stringid, int tid)
 			}
 		}
 	}
+	if (!replacemented && kind != NULL)
+	{
+		// Again, with decorate replacements
+		replacemented = true;
+		PClass *newkind = kind->ActorInfo->GetReplacement()->Class;
+		if (newkind != kind)
+		{
+			kind = newkind;
+			goto do_count;
+		}
+	}
 	return count;
 }
 
@@ -1827,6 +1840,8 @@ int DLevelScript::DoSpawn (int type, fixed_t x, fixed_t y, fixed_t z, int tid, i
 
 	if (info != NULL)
 	{
+		// Handle decorate replacements.
+		info = info->ActorInfo->GetReplacement()->Class;
 		actor = Spawn (info, x, y, z);
 		if (actor != NULL)
 		{
diff --git a/src/p_enemy.cpp b/src/p_enemy.cpp
index e5cf442bd..8f0041115 100644
--- a/src/p_enemy.cpp
+++ b/src/p_enemy.cpp
@@ -2210,6 +2210,9 @@ AInventory *P_DropItem (AActor *source, const PClass *type, int special, int cha
 				spawnz += source->height / 2;
 			}
 		}
+		// Handle decorate replacements.
+		type = type->ActorInfo->GetReplacement()->Class;
+
 		mo = Spawn (type, source->x, source->y, spawnz);
 		mo->flags |= MF_DROPPED;
 		mo->flags &= ~MF_NOGRAVITY;	// [RH] Make sure it is affected by gravity
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 2c5f631c4..18d4ca389 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -795,21 +795,6 @@ AInventory *AActor::FindInventory (const PClass *type) const
 			break;
 		}
 	}
-	if (item == NULL && type->ActorInfo->Replacement != NULL)
-	{ // Try again with a replacement type
-		PClass *newtype = type->ActorInfo->GetReplacement()->Class;
-
-		if (newtype != type)
-		{
-			for (item = Inventory; item != NULL; item = item->Inventory)
-			{
-				if (item->GetClass() == newtype)
-				{
-					break;
-				}
-			}
-		}
-	}
 	return item;
 }
 
@@ -3036,9 +3021,6 @@ AActor *AActor::StaticSpawn (const PClass *type, fixed_t ix, fixed_t iy, fixed_t
 		I_Error ("%s is not an actor\n", type->TypeName.GetChars());
 	}
 
-	// Handle decorate replacements.
-	type = type->ActorInfo->GetReplacement()->Class;
-
 	AActor *actor;
 
 	actor = static_cast<AActor *>(const_cast<PClass *>(type)->CreateNew ());
@@ -3729,6 +3711,9 @@ void P_SpawnMapThing (mapthing2_t *mthing, int position)
 	//		it to the unknown thing.
 	else
 	{
+		// Handle decorate replacements.
+		i = i->ActorInfo->GetReplacement()->Class;
+
 		const AActor *defaults = GetDefaultByType (i);
 		if (defaults->SpawnState == NULL ||
 			sprites[defaults->SpawnState->sprite.index].numframes == 0)
diff --git a/src/p_things.cpp b/src/p_things.cpp
index d3732764a..37d518c59 100644
--- a/src/p_things.cpp
+++ b/src/p_things.cpp
@@ -64,6 +64,10 @@ bool P_Thing_Spawn (int tid, int type, angle_t angle, bool fog, int newtid)
 	if ( (kind = SpawnableThings[type]) == NULL)
 		return false;
 
+	
+	// Handle decorate replacements.
+	kind = kind->ActorInfo->GetReplacement()->Class;
+
 	if ((GetDefaultByType (kind)->flags3 & MF3_ISMONSTER) && (dmflags & DF_NO_MONSTERS))
 		return false;
 
@@ -176,10 +180,14 @@ bool P_Thing_Projectile (int tid, int type, const char * type_name, angle_t angl
 	}
 	else
 	{
-		if ((kind = PClass::FindClass(type_name)) == NULL)
+		if ((kind = PClass::FindClass(type_name)) == NULL || kind->ActorInfo == NULL)
 			return false;
 	}
 
+
+	// Handle decorate replacements.
+	kind = kind->ActorInfo->GetReplacement()->Class;
+
 	defflags3 = GetDefaultByType (kind)->flags3;
 	if ((defflags3 & MF3_ISMONSTER) && (dmflags & DF_NO_MONSTERS))
 		return false;
diff --git a/src/thingdef.cpp b/src/thingdef.cpp
index cce554d4d..07ff28424 100644
--- a/src/thingdef.cpp
+++ b/src/thingdef.cpp
@@ -1305,10 +1305,6 @@ static FActorInfo * CreateNewActor(FActorInfo ** parentc, Baggage *bag)
 		{
 			SC_ScriptError ("Replaced type '%s' is not an actor", sc_String);
 		}
-		else if (!ti->IsDescendantOf (replacee))
-		{
-			SC_ScriptError ("'%s' must be derived from '%s' to replace it", typeName.GetChars(), sc_String);
-		}
 		replacee->ActorInfo->Replacement = ti->ActorInfo;
 	}
 	else
diff --git a/src/thingdef_codeptr.cpp b/src/thingdef_codeptr.cpp
index 96ad2c5f1..5ee1040c1 100644
--- a/src/thingdef_codeptr.cpp
+++ b/src/thingdef_codeptr.cpp
@@ -1143,12 +1143,15 @@ void A_SpawnItem(AActor * self)
 		if (useammo && !weapon->DepleteAmmo(weapon->bAltFire)) return;
 	}
 
+	// Handle decorate replacements.
+	missile = missile->ActorInfo->GetReplacement()->Class;
+
 	AActor * mo = Spawn( missile, 
 					self->x + FixedMul(distance, finecosine[self->angle>>ANGLETOFINESHIFT]), 
 					self->y + FixedMul(distance, finesine[self->angle>>ANGLETOFINESHIFT]), 
 					self->z - self->floorclip + zheight);
 
-	if (mo) 
+	if (mo)
 	{
 		AActor * originator = self;