A new update for Halo: The Master Chief Collection has added “experimental” cross-platform co-op for both Halo 3 and Halo 3: ODST.
The feature will let anyone on PC, Xbox One or Xbox Series X/S play these games’ campaigns co-operatively online together.
In patch notes, developer 343 Industries said the cross-play had been tested internally – though the company now needed “additional insight from real players with different networking setups”. If you experience issues, you’re encouraged to report them so 343 can improve the feature further.