diff --git a/main/biome.cpp b/main/biome.cpp
index 3361e10..3340780 100644
--- a/main/biome.cpp
+++ b/main/biome.cpp
@@ -281,22 +281,18 @@ void Biome::set_voxel_surfaces(const Vector<Variant> &voxel_surfaces) {
 #endif
 
 Ref<Biome> Biome::instance(const int seed) {
-	if (has_method("_instance")) {
-		return call("_instance", seed, Ref<Biome>());
-	}
+	Ref<Biome> inst;
 
-	return Ref<Biome>();
-}
+	inst = Ref<Biome>(Object::cast_to<Biome>(ClassDB::instance(get_class_name())));
+	ERR_FAIL_COND_V(!inst.is_valid(), inst);
 
-Ref<Biome> Biome::_instance(const int seed, Ref<Biome> biome) {
-	Ref<Biome> inst = biome;
-
-	if (!inst.is_valid())
-		inst.instance();
-
-	if (inst->get_script().is_null() && !get_script().is_null())
+	if (!get_script().is_null())
 		inst->set_script(get_script());
 
+	return call("_instance", seed, inst);
+}
+
+Ref<Biome> Biome::_instance(const int seed, Ref<Biome> inst) {
 	inst->set_current_seed(seed);
 	inst->set_level_range(_level_range);
 
diff --git a/main/biome.h b/main/biome.h
index 5355629..61a6c5a 100644
--- a/main/biome.h
+++ b/main/biome.h
@@ -119,7 +119,7 @@ public:
 #endif
 
 	Ref<Biome> instance(const int seed);
-	virtual Ref<Biome> _instance(const int seed, Ref<Biome> biome);
+	virtual Ref<Biome> _instance(const int seed, Ref<Biome> inst);
 
 	void setup();
 
diff --git a/main/dungeon.cpp b/main/dungeon.cpp
index db97e5b..80928ca 100644
--- a/main/dungeon.cpp
+++ b/main/dungeon.cpp
@@ -463,22 +463,18 @@ void Dungeon::set_environment_datas(const Vector<Variant> &environment_datas) {
 #endif
 
 Ref<Dungeon> Dungeon::instance(const int seed) {
-	if (has_method("_instance")) {
-		return call("_instance", seed, Ref<Dungeon>());
-	}
+	Ref<Dungeon> inst;
 
-	return Ref<Dungeon>();
-}
+	inst = Ref<Dungeon>(Object::cast_to<Dungeon>(ClassDB::instance(get_class_name())));
+	ERR_FAIL_COND_V(!inst.is_valid(), inst);
 
-Ref<Dungeon> Dungeon::_instance(const int seed, Ref<Dungeon> dungeon) {
-	Ref<Dungeon> inst = dungeon;
-
-	if (!inst.is_valid())
-		inst.instance();
-
-	if (inst->get_script().is_null() && !get_script().is_null())
+	if (!get_script().is_null())
 		inst->set_script(get_script());
 
+	return call("_instance", seed, inst);
+}
+
+Ref<Dungeon> Dungeon::_instance(const int seed, Ref<Dungeon> inst) {
 	inst->set_current_seed(seed);
 	inst->set_level_range(_level_range);
 
diff --git a/main/dungeon.h b/main/dungeon.h
index d384437..eda84c9 100644
--- a/main/dungeon.h
+++ b/main/dungeon.h
@@ -187,7 +187,7 @@ public:
 #endif
 
 	Ref<Dungeon> instance(const int seed);
-	virtual Ref<Dungeon> _instance(const int seed, Ref<Dungeon> dungeon);
+	virtual Ref<Dungeon> _instance(const int seed, Ref<Dungeon> inst);
 
 	void setup();
 
diff --git a/main/dungeon_corridor.cpp b/main/dungeon_corridor.cpp
index 78c846a..6b45320 100644
--- a/main/dungeon_corridor.cpp
+++ b/main/dungeon_corridor.cpp
@@ -53,17 +53,13 @@ int DungeonCorridor::get_dungeon_room_count() const {
 	return _dungeon_rooms.size();
 }
 
-Ref<DungeonRoom> DungeonCorridor::_instance(const int seed, Ref<DungeonRoom> dungeon_room) {
-	Ref<DungeonCorridor> inst = dungeon_room;
-
-	if (!inst.is_valid())
-		inst.instance();
-
+Ref<DungeonRoom> DungeonCorridor::_instance(const int seed, Ref<DungeonRoom> inst) {
 	DungeonRoom::_instance(seed, inst);
 
-	inst->set_max_connections(_max_connections);
+	Ref<DungeonCorridor> cinst = inst;
+	cinst->set_max_connections(_max_connections);
 
-	return inst;
+	return cinst;
 }
 
 DungeonCorridor::DungeonCorridor() {
diff --git a/main/dungeon_corridor.h b/main/dungeon_corridor.h
index 50991ed..b5c109c 100644
--- a/main/dungeon_corridor.h
+++ b/main/dungeon_corridor.h
@@ -40,7 +40,7 @@ public:
 
 	int get_dungeon_room_count() const;
 
-	Ref<DungeonRoom> _instance(const int seed, Ref<DungeonRoom> dungeon_room);
+	Ref<DungeonRoom> _instance(const int seed, Ref<DungeonRoom> inst);
 
 	DungeonCorridor();
 	~DungeonCorridor();
diff --git a/main/dungeon_room.cpp b/main/dungeon_room.cpp
index 11bbd09..e8094a5 100644
--- a/main/dungeon_room.cpp
+++ b/main/dungeon_room.cpp
@@ -321,22 +321,18 @@ void DungeonRoom::set_entity_datas(const Vector<Variant> &entity_datas) {
 #endif
 
 Ref<DungeonRoom> DungeonRoom::instance(const int seed) {
-	if (has_method("_instance")) {
-		return call("_instance", seed, Ref<DungeonRoom>());
-	}
+	Ref<DungeonRoom> inst;
 
-	return Ref<DungeonRoom>();
-}
+	inst = Ref<DungeonRoom>(Object::cast_to<DungeonRoom>(ClassDB::instance(get_class_name())));
+	ERR_FAIL_COND_V(!inst.is_valid(), inst);
 
-Ref<DungeonRoom> DungeonRoom::_instance(const int seed, Ref<DungeonRoom> dungeon_room) {
-	Ref<DungeonRoom> inst = dungeon_room;
-
-	if (!inst.is_valid())
-		inst.instance();
-
-	if (inst->get_script().is_null() && !get_script().is_null())
+	if (!get_script().is_null())
 		inst->set_script(get_script());
 
+	return call("_instance", seed, inst);
+}
+
+Ref<DungeonRoom> DungeonRoom::_instance(const int seed, Ref<DungeonRoom> inst) {
 	inst->set_current_seed(seed);
 	inst->set_level_range(_level_range);
 
diff --git a/main/dungeon_room.h b/main/dungeon_room.h
index 8a96799..232f60e 100644
--- a/main/dungeon_room.h
+++ b/main/dungeon_room.h
@@ -156,7 +156,7 @@ public:
 #endif
 
 	Ref<DungeonRoom> instance(const int seed);
-	virtual Ref<DungeonRoom> _instance(const int seed, Ref<DungeonRoom> dungeon_room);
+	virtual Ref<DungeonRoom> _instance(const int seed, Ref<DungeonRoom> inst);
 
 	void setup();
 
diff --git a/main/planet.cpp b/main/planet.cpp
index b72edee..055aeca 100644
--- a/main/planet.cpp
+++ b/main/planet.cpp
@@ -226,22 +226,18 @@ void Planet::set_voxel_surfaces(const Vector<Variant> &voxel_surfaces) {
 #endif
 
 Ref<Planet> Planet::instance(const int seed) {
-	if (has_method("_instance")) {
-		return call("_instance", seed, Ref<Planet>());
-	}
+	Ref<Planet> inst;
 
-	return Ref<Planet>();
-}
+	inst = Ref<Planet>(Object::cast_to<Planet>(ClassDB::instance(get_class_name())));
+	ERR_FAIL_COND_V(!inst.is_valid(), inst);
 
-Ref<Planet> Planet::_instance(const int seed, Ref<Planet> planet) {
-	Ref<Planet> inst = planet;
-
-	if (!inst.is_valid())
-		inst.instance();
-
-	if (inst->get_script().is_null() && !get_script().is_null())
+	if (!get_script().is_null())
 		inst->set_script(get_script());
 
+	return call("_instance", seed, inst);
+}
+
+Ref<Planet> Planet::_instance(const int seed, Ref<Planet> inst) {
 	inst->set_id(_id);
 	inst->set_current_seed(seed);
 	inst->set_level_range(_level_range);
diff --git a/main/planet.h b/main/planet.h
index 7c8012d..94611d1 100644
--- a/main/planet.h
+++ b/main/planet.h
@@ -109,7 +109,7 @@ public:
 #endif
 
 	Ref<Planet> instance(const int seed);
-	virtual Ref<Planet> _instance(const int seed, Ref<Planet> planet);
+	virtual Ref<Planet> _instance(const int seed, Ref<Planet> inst);
 
 	void setup();