The question of whether "Call of Duty" and "FC 25" will work on the Steam Deck OLED 512GB depends on the compatibility of the games with the Steam Deck. Steam offers a system that indicates whether a game is playable on the Steam Deck. Games marked as "green" are fully compatible, while games with a "yellow question mark" may have some issues. You can check the compatibility of the games in your Steam library to make sure they will run on the Steam Deck.