Marathon’s Symbiosis Gameplay Trailer Reveals the 8 December Xbox Update

Bungie has released a gameplay trailer for Marathon’s Symbiosis update, which arrives on Xbox Series X|S on 8 December. The update is included for everyone who owns the game, adding the first permanent PvE mode, a reworked Perimeter, a new Runner shell and experimental Team Deathmatch. From 8 to 15 December, anyone can download and play the full game during Open Play Week.

What’s coming in Symbiosis

Fungal growth and alien life have reshaped Perimeter, opening new playable spaces that include the underground Burrows and the submerged Reservoir. The Tick Queen, which Bungie has previously called its largest combatant yet, “lurks deep beneath the surface”.

Expedition is phase one of the new PvE-only mode. It’s built around a three-run series you can play solo or with a crew, with fresh combat and environmental challenges and no other Runners hunting you. Flash Boosts let you shape your build during a run.

Deathmatch, labelled as a beta, is an experimental PvP mode of short 3v3 Team Deathmatch fights in which two crews battle for points without risking their permanent loadout. Limbo is a new social space where Runners can meet, test weapons and gear on firing ranges, and challenge each other in the dueling pit.

The new Bishop shell is a fast, surgical, blade-wielding robot. New weapons include the V17 Flamethrower, built for heat and short-range area denial, and the Maverick, a new revolver archetype with a hand-cannon feel. The official trailer also shows a throwing knife and a hack grenade among the new gear.

Open Play Week and Crew Up

Bungie is opening the game to everyone from 8 to 15 December so players can try everything Symbiosis adds, including Expedition, Bishop, the updated Perimeter and the new gear. If you buy Marathon after that week, you keep the items and progression you unlocked.

The Crew Up event runs from 20:00 GMT on 8 December to 18:00 GMT on 22 December, and after Open Play Week you need to own the game to keep taking part. Redeem the code DMA-T7Y-XJL on Bungie.net once Symbiosis is live, then complete Expedition challenges with at least one other player who has also redeemed the code. They cannot be done solo.

Completing consecutive challenges unlocks Codex cosmetics for each teammate, including the Queen’s Nest emblem, Queen’s Dominion background, Queen’s Maw weapon sticker, Cluster Bunch weapon charm, Arata Vectus Destroyer skin and the Exterminator title.

Marathon is £34.99 on the Xbox Store, or £49.99 for the Deluxe Edition, and it is not on Game Pass. For the wider roadmap, including what’s planned for March, see our Marathon: everything we know guide.