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.
Warhammer: Dwarfs take everything as Serious Business. Seriously, it's suggested that they are physically incapable of not giving their all when they strive to do something. This explains their skill as craftsmen. Dwarfs also take two things very seriously specifically: their Grudges, and their Badass Beards.
No kidding. One famous Dwarf Grudge was by the clan of Karak Azul, who lost ten thousand warriors in a landslide caused by an exploding goblin shaman at a battle in Grimspike Pass. Since the offending goblin died and the Dwarfs won in the end anyway, the Dwarfs declared the Grudge against the pass itself, vowing that they will never stop until every bit of wealth has been mined out and the mountain reduced to dust.
Bugman's Brewery, where the legendary ale known as Bugman's XXXXX was created, was once considered the greatest of all Dwarfish brewhouses. Then the Greenskins attacked, tore down the brewery, killed most of the Bugman clan, and drank almost all of the beer. Note which part of that was emphasized.
The Dwarfs once started a vicious war against the Elves because their arrogant Jerkass king shaved the beard of one of their emissaries as an insult.
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.