Star Wars MUSH (commonly referred to as SW1) is a text-based online role-playing game. Star Wars MUSH was created in May 1991 and was released to the public in January 1992. The game predates the majority of Star Wars Expanded Universe and as such largely deviates from the established Star Wars universe set after Return of the Jedi. The game scenario system is based on the discontinued West End Games' Star Wars role-playing game.