diff --git a/src/g_levellocals.h b/src/g_levellocals.h
index 9764ebb39..d34f2190e 100644
--- a/src/g_levellocals.h
+++ b/src/g_levellocals.h
@@ -762,7 +762,7 @@ public:
 	DVisualThinker* VisualThinkerHead = nullptr;
 
 	// links to global game objects
-	TArray<DBehavior*> ActorBehaviors;
+	TArray<DBehavior*> ActorBehaviors, ClientSideActorBehaviors;
 	TArray<TObjPtr<AActor *>> CorpseQueue;
 	TObjPtr<DFraggleThinker *> FraggleScriptThinker = MakeObjPtr<DFraggleThinker*>(nullptr);
 	TObjPtr<DACSThinker*> ACSThinker = MakeObjPtr<DACSThinker*>(nullptr);
@@ -780,7 +780,10 @@ public:
 		if (b.Level == nullptr)
 		{
 			b.Level = this;
-			ActorBehaviors.Push(&b);
+			if (b.IsClientside())
+				ClientSideActorBehaviors.Push(&b);
+			else
+				ActorBehaviors.Push(&b);
 		}
 	}
 
@@ -789,7 +792,10 @@ public:
 		if (b.Level == this)
 		{
 			b.Level = nullptr;
-			ActorBehaviors.Delete(ActorBehaviors.Find(&b));
+			if (b.IsClientside())
+				ClientSideActorBehaviors.Delete(ClientSideActorBehaviors.Find(&b));
+			else
+				ActorBehaviors.Delete(ActorBehaviors.Find(&b));
 		}
 	}
 
diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index b948d4734..b698b3eec 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -387,6 +387,7 @@ void FLevelLocals::ClearLevelData(bool fullgc)
 	levelMesh = nullptr;
 	VisualThinkerHead = nullptr;
 	ActorBehaviors.Clear();
+	ClientSideActorBehaviors.Clear();
 	if (screen)
 		screen->SetAABBTree(nullptr);
 }
diff --git a/src/playsim/p_mobj.cpp b/src/playsim/p_mobj.cpp
index 0b01f2cfe..e93190c8f 100644
--- a/src/playsim/p_mobj.cpp
+++ b/src/playsim/p_mobj.cpp
@@ -539,6 +539,8 @@ DBehavior* AActor::AddBehavior(PClass& type)
 			return nullptr;
 
 		b->Owner = this;
+		b->ObjectFlags |= (ObjectFlags & (OF_ClientSide | OF_Transient));
+
 		Behaviors[type.TypeName] = b;
 		Level->AddActorBehavior(*b);
 		IFOVERRIDENVIRTUALPTRNAME(b, NAME_Behavior, Initialize)
@@ -653,6 +655,9 @@ void AActor::MoveBehaviors(AActor& from)
 	if (&from == this)
 		return;
 
+	if (IsClientside() != from.IsClientside())
+		I_Error("Cannot move Behaviors between client-side and world Actors");
+
 	// Clean these up properly before transferring.
 	ClearBehaviors();
 
diff --git a/src/scripting/vmiterators.cpp b/src/scripting/vmiterators.cpp
index 730f09226..f8cac10d2 100644
--- a/src/scripting/vmiterators.cpp
+++ b/src/scripting/vmiterators.cpp
@@ -446,9 +446,10 @@ public:
 		Reinit();
 	}
 
-	DBehaviorIterator(const FLevelLocals& level, PClass* type, PClass* ownerType)
+	DBehaviorIterator(const FLevelLocals& level, PClass* type, PClass* ownerType, bool clientSide)
 	{
-		for (auto& b : level.ActorBehaviors)
+		auto& list = clientSide ? level.ClientSideActorBehaviors : level.ActorBehaviors;
+		for (auto& b : list)
 		{
 			if (ownerType != nullptr && !b->Owner->IsKindOf(ownerType))
 				continue;
@@ -498,7 +499,7 @@ DEFINE_ACTION_FUNCTION_NATIVE(DBehaviorIterator, CreateFrom, CreateBehaviorItFro
 
 static DBehaviorIterator* CreateBehaviorIt(PClass* type, PClass* ownerType)
 {
-	return Create<DBehaviorIterator>(*primaryLevel, type, ownerType);
+	return Create<DBehaviorIterator>(*primaryLevel, type, ownerType, false);
 }
 
 DEFINE_ACTION_FUNCTION_NATIVE(DBehaviorIterator, Create, CreateBehaviorIt)
@@ -509,6 +510,19 @@ DEFINE_ACTION_FUNCTION_NATIVE(DBehaviorIterator, Create, CreateBehaviorIt)
 	ACTION_RETURN_OBJECT(CreateBehaviorIt(type, ownerType));
 }
 
+static DBehaviorIterator* CreateClientSideBehaviorIt(PClass* type, PClass* ownerType)
+{
+	return Create<DBehaviorIterator>(*primaryLevel, type, ownerType, true);
+}
+
+DEFINE_ACTION_FUNCTION_NATIVE(DBehaviorIterator, CreateClientSide, CreateClientSideBehaviorIt)
+{
+	PARAM_PROLOGUE;
+	PARAM_CLASS(type, DBehavior);
+	PARAM_CLASS(ownerType, AActor);
+	ACTION_RETURN_OBJECT(CreateClientSideBehaviorIt(type, ownerType));
+}
+
 static DBehavior* NextBehavior(DBehaviorIterator* self)
 {
 	return self->Next();
diff --git a/wadsrc/static/zscript/actors/actor.zs b/wadsrc/static/zscript/actors/actor.zs
index 15bd68236..123fe91be 100644
--- a/wadsrc/static/zscript/actors/actor.zs
+++ b/wadsrc/static/zscript/actors/actor.zs
@@ -88,6 +88,7 @@ class BehaviorIterator native abstract final version("4.15.1")
 {
 	native static BehaviorIterator CreateFrom(Actor mobj, class<Behavior> type = null);
 	native static BehaviorIterator Create(class<Behavior> type = null, class<Actor> ownerType = null);
+	native static BehaviorIterator CreateClientSide(class<Behavior> type = null, class<Actor> ownerType = null);
 
 	native Behavior Next();
 	native void Reinit();