Forge is a game mode originally released in Halo 3 designed by Bungie to allow players to customize, save, and share maps for Custom Games. Forge was originally created to be used by players to make relatively simple changes to maps in order to tweak their gameplay experience. Maps altered in Forge are referred to as map variants, and possible alterations include the modification of player spawn points, gametype objective points, weapons spawns, and the addition of scenery items such as crates, Fusion coils, gravity lifts, teleporters, and various other items - In Forge, players can add items that aren't available in unmodified maps.