A post-apocalyptic wasteland from the fallout of nuclear war, where food and water is scarce and survival difficult. Bottle caps and other items have become the currency of the land. So, why not old trading cards from before the bombs went off? A card game would fit perfectly into the decrepit mythos of the Fallout universe. Finding dusty old trading cards in abandoned buildings can be just as satisfying as finding that brand new weapon.
You could even set up a secondary story in a Fallout game with this. Small snippets of story you can see as you collect cards based on the heroes of the past wars and learn more about them. As you wander the wasteland, stopping at settlements to stock up on ammo and food, finding a fellow survivor to sit and play a game of cards with sounds like the perfect distraction.