Halo Campaign Evolved.
Now with classic multiplayer.

Yes — with MJOLNIR Core, you can play classic competitive multiplayer in Halo Campaign Evolved. Our community-made, open-source modding framework adds Slayer and Capture the Flag on all 19 original Halo: Combat Evolved multiplayer maps, including the Halo PC maps. This is a multiplayer mod, separate from the game's official campaign and co-op features, and is currently in alpha.

Install the MJOLNIR Launcher, set up mods in My Mods, then open Multiplayer and select Install multiplayer. Launch Halo Campaign Evolved, choose MULTIPLAYER from the main menu, pick a map and game type, invite friends to your fireteam, and start the game. Each player needs their own game installation and the same maps.

MJOLNIR adds Slayer and Capture the Flag to all 19 classic maps. The framework also supports Team Slayer, King of the Hill, and Oddball in its multiplayer menu. A mode is available when both the installed map and its game variant support it; check the map's listing and your in-game mode selector.

All 19 classic Halo: Combat Evolved multiplayer maps are available through MJOLNIR, including Blood Gulch, Sidewinder, Battle Creek, Hang 'Em High, and Chill Out, plus Halo PC maps such as Danger Canyon, Death Island, Gephyrophobia, Ice Fields, Infinity, and Timberland. The launcher installs the full classic map collection.

Yes. MJOLNIR provides a custom level pipeline, a Blender addon, a tag editor, and command-line tools for authoring maps and changing weapons, textures, and scripts. Creators can package and publish content through the hub. Map creation is an advanced workflow: the current classic-map conversion pipeline needs Unreal Editor and the MJOLNIRMaterials project for cooking, and published map packs go through review.

Up to 16 players, on every classic map. Each player needs their own PC and their own copy of the game, with the same maps installed. More than two players on one PC isn't supported yet.

You need Windows 10 or 11 (64-bit), the MJOLNIR Launcher, and your own copy of Halo Campaign Evolved. The multiplayer alpha works on both the Steam and the Xbox app / Game Pass versions, and Steam and Game Pass players can play in the same game. If a Steam player is dropped soon after joining a Game Pass host, check that the host's Xbox account allows cross-network play in its privacy settings. MJOLNIR is free and open source; the base game is a separate requirement.

Join the MJOLNIR Discord to find people to play with, get setup help, report alpha issues, and share maps and mods. The hub also has map pages with comments and ratings, creator documentation, and a games page for reported multiplayer lobbies.