Marathon’s Symbiosis update arrives on December 8, bringing a PvE Expedition mode and an experimental team Deathmatch beta. The update is planned for all players, according to PlayStation.Blog.
Symbiosis will also rework Perimeter, introduce a social space called Limbo and add a Runner chassis and two weapons. An Open Play Week is planned alongside the launch, from December 8 to 15.

Expedition removes the PvP threat
The first phase of Expedition is exclusively PvE. Players can go in alone or as a team, taking on combat and environmental challenges in sets of three runs. There is no threat from other players in the mode.
During a run, Flash Boosts let players shape their loadout. The mode gives players a way to tackle combat and environmental challenges without having to contend with a rival team.
Deathmatch keeps permanent gear safe
Deathmatch centers on direct competition between two teams of three. Teams score points, but players do not risk their permanent gear in the process.
The mode is experimental and will launch in beta, offering team competition without putting permanent equipment on the line.
Perimeter, Limbo and the new arsenal
The reworked Perimeter includes new playable spaces, among them the underground Burrows and the submerged Reservoir. The area will also feature the Tick Queen.
Limbo is a social space with firing ranges where players can try weapons and equipment. It also has a dueling arena.
The update adds Bishop, a fast Runner chassis wielding a blade. The new weapons are the V17 flamethrower, intended for close-range area control, and the Maverick, a new type of revolver.
Open Play Week and play requirements
Open Play Week runs from December 8 to 15, alongside Symbiosis. Marathon is available on PS5 and supports cross-play and cross-save.
The game requires an internet connection and, on console, a paid subscription sold separately. Cross-save requires a compatible copy of the game on each system used, plus a network account linked to Bungie.net. Copies for other versions are sold separately.
Expedition and Deathmatch offer different approaches to combat: Expedition’s first phase removes the PvP threat, while the experimental Deathmatch beta keeps team competition without putting permanent gear at risk.