If you’ve been waiting for Bungie to do something different with Marathon, the upcoming Symbiosis update might be exactly what you’ve been looking for. Bungie has released a new trailer showcasing what’s coming on December 8, 2026, including a permanent PvE roguelike mode, 3v3 Team Deathmatch, a new Runner shell, additional weapons, and more.
And considering how things have been going for Marathon, I’d say these additions couldn’t have come at a better time.
One of the biggest additions coming with Symbiosis is Expedition, a permanent PvE-only mode that introduces roguelike mechanics to Marathon. Instead of constantly worrying about other players hunting you down and taking your gear, you’ll face computer-controlled enemies across a series of increasingly difficult encounters.
Expedition can be played solo or with a crew and features three connected runs. Along the way, players will acquire temporary upgrades called Flash Boosts, allowing them to improve their builds and adapt to the challenges ahead....
