Call of Duty studio Sledgehammer reportedly worked on a Halo multiplayer prototype before it got canned
Following Microsoft’s acquisition of Activision Blizzard, Xbox explored leveraging Activision’s expertise for its flagship Halo franchise. According to Rebs Gaming, a YouTuber with a track record of accurate Halo reporting, Microsoft enlisted Sledgehammer Games—the studio behind Call of Duty titles including Modern Warfare 3, Vanguard, and WW2—to develop a Halo multiplayer prototype.
The project began in June 2026 but was cancelled in July after testing only basic gameplay elements such as player movement mechanics. Despite the prototype’s cancellation, the report suggests Microsoft may continue exploring partnerships between Activision studios and Halo development in the future.
The news comes amid ongoing turbulence in Halo’s development cycle. The recently released Halo: Campaign Evolved has received mixed reception, with critics attributing issues to the game’s troubled development and complications from coordinating with 15 co-developing studios. This apparent mismanagement has led some to question how Microsoft might better oversee future Halo projects.
The exploration of cross-studio collaboration reflects Microsoft’s broader strategy of consolidating its gaming divisions following the Activision acquisition, potentially bringing Sledgehammer Games’ multiplayer expertise to bear on a franchise that has struggled with live-service execution.