Bungie’s Symbiosis update for Marathon launches on December 8, adding a permanent PvE mode called Expedition, a beta 3v3 deathmatch mode, a new Bishop Runner shell and a reworked Perimeter zone. It is available on PlayStation 5, Xbox Series X|S and Steam, with full cross-play and cross-save, and the studio is running a free play week alongside it.

The update was first planned for September 22, then moved into December when Bungie dropped its fixed seasonal schedule. According to Bungie, the change gives the team more room to build, test and improve features before they ship. A gameplay trailer and press material went out on November 10.

What is in the Symbiosis update?

The headline addition is Expedition, a mode where you fight computer-controlled enemies instead of other players. Bungie’s press material describes it as a PvE-only mode built around a series of three runs, which you can play solo or with a crew. Flash Boosts shape your build as a run goes on. Bungie labels this as Phase 1, so more is expected later.

Here is the rest of the list:

  • Perimeter changes: fungal growth and alien life have altered the zone, adding underground spaces called the Burrows and a submerged area called the Reservoir. Bungie says the Tick Queen lurks below the surface.
  • Deathmatch (Beta): a 3v3 team mode where two crews compete for points without risking a permanent loadout. ComicBook describes it as a beta while Bungie decides how best to implement it.
  • Limbo: a social hub with firing ranges for testing weapons and gear, plus a dueling pit.
  • Bishop Runner shell: a new shell themed around a fast, blade wielding robot.
  • New weapons: the V17 Flamethrower for short range area denial, and the Maverick, a revolver with a hand cannon feel.

Bungie also lists additional gear and rewards without naming them, so the full content list is not yet public.

When can you play, and what does it cost?

Symbiosis arrives on December 8 and is described as available to all players. Open Play Week runs from December 8 to December 15, and during that window anyone can download and play the full game for free. ComicBook reports that progress made during the week carries over to the full game, and that the week includes Expedition, Bishop and the updated Perimeter.

A separate Crew Up event runs from December 8 at 12 PM PT to December 22 at 10 AM PT. Players redeem a code on Bungie’s website after launch to unlock a new Events section in the Codex, with extra objectives and rewards. Bungie’s materials say the Crew Up rewards are limited time.

Prices were not stated in the material we reviewed. Marathon is sold in Standard and Deluxe editions, but the sources do not list what each costs in any currency. On console, online play requires a paid subscription that is sold separately.

Who is this update for?

Players who wanted a PvE option get the most from it. Expedition is a permanent mode, and it can be played alone, which lowers the barrier for anyone put off by player versus player extraction matches.

Returning players have the clearest reason to come back. The reworked Perimeter, the Limbo hub and two new weapons give them something new to try, and Open Play Week removes the cost of checking.

New players can use the free week as a trial. Because progress carries over, time spent in the week is not wasted if they decide to buy.

Competitive players should treat Deathmatch with caution. It is a beta and an experimental mode, so rules, balance and future availability may change.

What is still unknown?

Bungie has not detailed the “and more” items in the update, what comes after Phase 1 of Expedition, or the Standard and Deluxe edition prices. Nothing in the sources says how long Deathmatch will stay in beta. The Crew Up code and reward list are also best confirmed on Bungie’s own site, since limited time offers can change.

What should you do next?

Mark December 8 on your calendar and check Bungie’s Symbiosis press page or the Marathon store listing on your platform for the edition prices in your currency. If you play on console, confirm your subscription is active before the free week starts, and redeem the Crew Up code before the event closes on December 22.