Halo games don't run on Steam Deck

pcgamer.com:

Microsoft has revealed which of its games will be able to run on the Steam Deck, but there are some unfortunate absences thanks to anti-cheat.

While games Deathloop, Prey, and Psychonauts 2 have all been given the «Verified» stamp of approval, some of its bigger releases won't run on the handheld (thanks, Eurogamer). Halo Infinite, the Master Chief Collection, Gears of War 5, and Microsoft Flight Simulator X won't be supported which Microsoft says is «due to anti-cheat.» They're some startling omissions—while I wouldn't expect Flight Sim to have the best time on handheld anyway, it's a shame to see Halo Infinite on the list of unsupported games. Of course, you can still stream them through the likes of GeForce Now, but running directly on Linux is a no-go.

They aren't the only games to lose out on Steam Deck support thanks to anti-cheat measures. Bungie revealed that Destiny 2 would also be unsupported, threatening to ban anyone who attempts to bypass the game's incompatibility. It's become a rising issue with the Deck's Linux OS—not every developer has faith that they could combat cheaters coming through the handheld. It's the same situation with Fortnite, with Epic CEO Tim Sweeney telling The Verge: «We don’t have confidence that we’d be able to combat cheating at scale under a wide array of kernel configurations including custom ones.»

On the bright side, other great Microsoft games have been plonked in the «Playable» category meaning they can work with some small tweaks here and there. Sea of Thieves is on the list since it appears to have less rigorous cheat detection than its unsupported friends. You should also be able to play both Forza Horizon 4 and Forza Horizon 5 with some tweaking. Microsoft has a full list