Bungie's Marathon Season 3 reportedly features major PvE expansion

Leaks from a reported private playtest suggest that Bungie’s Marathon Season 3 will feature a substantial cooperative PvE mode. While Bungie has officially confirmed that Season 3 will launch on September 22, 2026, with a full PvE mode and major Perimeter expansions, specific gameplay details remain unconfirmed.

According to the leaked information, the new PvE experience may consist of four connected runs where players gather resources and improve builds to determine final reward tiers. The Perimeter area is reportedly receiving a massive expansion, including a large underground section and up to four boss encounters, such as the Tick Queen and Compiler.

Other rumored features include a “Flash Boost” system for creating temporary character builds, new weapons, equipment, and a new Runner shell. These updates follow the experimental Vault Breaker mode from Season 2, which served as a testbed for these larger systems. The upcoming season arrives as Bungie seeks to revitalize player engagement following a decline in Steam population numbers.