Layers are separate entities within the editor. A layer can contain objects, paths, regions, lights, etc. and may be chosen to be part of one or more game modes that are referred to by name ("conquest", "CTF", etc.). These are then loaded into the game on a per Lua basis. Layers in the "common" game mode are always loaded if the world is loaded, but other game modes must be loaded explicitly in a mission Lua. Therefore, all objects, regions, etc. in the layers for a given Game Mode are not present in-game unless that mode is loaded.