Bungie’s Symbiosis update for Marathon launches December 8, bringing a permanent cooperative PvE mode called Expedition and marking what the studio describes as the first phase of its PvE plans.

In Expedition, players face increasingly difficult computer-controlled enemies instead of competing against other players, with the option to play solo or as a crew.

Teams can use randomized, temporary Flash Boost upgrades to strengthen their builds and adapt to each run’s escalating challenges.

The update also reshapes Perimeter with fungal growth and alien life, adding the underground Burrows and submerged Reservoir, where players can encounter the large Tick Queen enemy.

Bishop, a new melee-focused Runner shell, emphasizes speed and mobility; its abilities include a throwing knife, a super-jump and a sword-powered dash through enemies.

Players will also get new weapons and gear, including the Maverick hand cannon revolver, V17 Flamethrower, throwing knives and hack grenades.

A beta for experimental 3v3 Deathmatch will offer short PvP matches without the risk of permanently losing players’ loadouts.

Limbo adds a non-combat social space for meeting other Runners, testing weapons and gear at a firing range, and dueling.

Marathon will be free to play during Open Play Week, December 8–15, 2026; players who buy the game afterward keep their unlocked items and progress, but must own it to continue event challenges after December 15.

The free week gives Bungie a chance to draw players in with a noncompetitive option, though the update’s effect on Marathon’s player numbers remains uncertain.

Marathon is available on PlayStation 5, Xbox Series X|S and PC via Steam, with another major update planned for March 2027.