For those that don’t know, Black Ops 3 is currently borked on Deck. Not a Proton issue. It’s an OS issue. Something in a recent SteamOS update itself broke the game. Game worked flawlessly before, and still works on other Linux distros. The game’s functionality varies between users. Some can at least play solo zombies, with just a crash on the FMV after a match. Others (like myself) crash when loading a map.

So while we wait for Valve to fix this issue, I can offer a zombies alternative. Obviously there’s Black Ops and Black Ops 2. Another option is Garry’s Mod with the nZombies custom game mode. nZombies is Nazi Zombies, but ported over to Gmod. It’s janky, but good enough to fix that zombies itch.