A few games Games Workshop actually did in cooperation with the american publisher West End Games. Cosmic Encounter is one of this products, being a release of the well-known game.

In this game, different powers in the Universe battle for predomination. Each player rules a different race, possessing different special abilities which allow to change the rules in some way. The basic rules of the game are fairly easy - the fun begins when different players try to make best use of their abilities, possibly cancelling the abilities of other players. The game is played best with 4 or more players, since then the real fun begins...