Halo 5: Forge is the first time the Forge component of the Halo first-person shooter series is available on a PC platform. This free release has the Forge mode, first introduced in Halo 3, which allows players to create and share maps for custom maps and full game modes. Creations can be shared with the Halo 5: Guardians Xbox One game and vice versa. It does not include any other content from Halo 5 such as the single-player mode or the full multiplayer part, but it lets players host and join custom games for Forge maps for up to sixteen players with all game elements and assets from the full game. Next to weapons, vehicles and game this includes prefabs, pre-assembled collections of blocks that can be saved and shared.
While multiplayer matches are possible it did not include any matchmaking functionalities when it was launched. Players need to exchange Xbox gamertags outside of the game to host and join each other's custom games. This release contains the entire Arena mode from Halo 5: Guardians with all 15 pre-made maps to play or edit. Available maps can be browsed through a content browser. Forge was not available on Xbox One at launch, but it was added in the Halo 5Cartographer’s Gift update in December 2015.