In Blood Bowl, the eponymous game has replaced warfare. And this is in an Alternate History version of Warhammer. The dwarven hatred of orcs has been reduced to hooliganism. The dark elves and the high elves settle their differences kicking a rugby ball around instead of killing each other. Khorne no longer wants blood and skulls, he wants blood and touchdowns.
One reason the mightiest of the gods aren't directly trying to fix the mess the world's in is due to their obsession with "The Games of Divinity," which are apparently the Platonic Ideal of Fun. A lot of the fans don't like this explanation.
There's also Sigereth, The Player Of Games, who's basically the Demoness of Serious Business. She manifests as a game board, and does absolutely nothing but play games with any and all challengers... with ridiculously high stakes for winning or losing. Think memories, skills, your body and soul... to give an example of how serious it is, most spirits are allowed to take an advantage that makes them immune to mind-control that would cause them to violate one key rule of their existence. Sigereth? Cannot be compelled to lose board games.