Marathon's Symbiosis update brings PvE Expedition runs on December 8

Marathon's December 8 Symbiosis update will give players a way to explore Tau Ceti IV without competing against other crews. Expedition launches as the first phase of a PvE-only mode, alongside changes to competitive play and a new place to meet between runs.

Expedition is organized around a series of three runs, playable alone or with a crew. Its challenges come from combat and the environment, while temporary Flash Boosts help shape a build during a run. The updated Perimeter zone adds the underground Burrows, the submerged Reservoir and an encounter with the Tick Queen. PlayStation's Symbiosis overview.

The competitive alternative is a beta version of three-versus-three Team Deathmatch. It lets two crews compete for points without risking their permanent loadouts. Limbo, a new social area, includes firing ranges and a dueling pit, offering somewhere to try equipment before committing to another outing.

Bungie has also set two different promotional windows. Open Play Week begins with the update on December 8 and ends December 15. Crew Up rewards remain available through December 22 for players teaming with friends through supported Bungie and platform friend connections. That gives the Crew Up rewards a separate, longer window. Bungie's announcement and access terms.

Marathon is available on PS5, Xbox Series X|S and Steam with cross-play and cross-save. Bungie's terms require internet access and a paid console subscription; cross-save also requires compatible game access on each system and linked platform accounts. Players trying the December event should check those requirements before arranging a cross-platform session. Bungie is introducing Expedition in phases and releasing Team Deathmatch as a beta.