Blood Bowl
This game was created by Jervis Johnson. 'nuff said.
Blood Bowl is a game set in the Warhammer Fantasy Battle universe. In-universe, it is a sports game somewhat like American Football but with a level of violence more akin to Canadian Ice Hockey. The in-universe explanation of the game is that during a battle between Dwarfs and Night Goblins, they found a chest of rulebooks, magazines, and brochures detailing "Amorikan Footbowl" and after the Dwarf sage interpreted them (going mad in the process) they played the game to settle the battle, the game then growing in popularity and entirely replacing war in the Warhammer universe during seasons. Otherwise it's the same setting as Warhammer Fantasy, and may even be the exact same if you want to think that it is. It is played by teams from each of the major factions who set aside their differences for the duration of the season. Out-of-universe, it is a game where each player manages a Blood Bowl team as they accumulate experience and injuries.
During seasons all wars in the world stop since Blood Bowl takes precedence above all other facets of life, even in the Warp. There used to be multiple leagues, but now only one survives. High Elves and the wizards of the Empire maintain crystal ball networks similar to television stations that show programs filmed with Campaigns for Real Arcanery (or Camras) with recorded images and sounds sent via a spell called Cabalvision. Each station is named with the same acronyms as real world stations with them meaning more humorous things (NBC=Necromancers Broadcasting Circle, Channel 7 CBS=Crystal Ball Service, and so on), although only one (ABC=Association of Broadcasting Conjurers) has the rights to broadcast Blood Bowl games. The announcers of all league Blood Bowl matches are a vampire named Jim, and an Ogre retired player named Bob Bifford. In the vidya the two talk CONSTANTLY to the point of annoyance. On the tabletop, they do absolutely nothing but had little minis you could buy to make your playing table look more complete (although with the advent of the vidya players sometimes imitate them to mock the opposing player, resulting in a well deserved mini down the windpipe).
It was produced by Specialist Games for a long time, but now like all the other Specialist Games it is on Games Workshop's back burner. Thankfully, there's a couple of computer games based on it (with a sequel to the most recent in the works!) that is almost the exact same as the tabletop (going as far as to use the Blood Bowl tabletop handbook for the rules in the vidya), and a card game by Fantasy Flight Games.