Greg Costikyan, who also goes by the name Designer X, is an American individual who creates games and writes science fiction. Costikyan's professional life includes work in practically every type of game that exists, such as wargames using hex grids, RPGs, board games, card games, video games, online multiplayer games, and games for mobile devices. He has received Origins Awards for some of the games he has designed. Costikyan served as the game designer who created the original version of Star Wars: The Roleplaying Game, and his name is listed under "original design" for all later versions of the game.
The following West End Games books give credit to Greg Costikyan:
- Star Wars: The Roleplaying Game (credited for "design")
- The Star Wars Sourcebook (credited for "additional development")
- Star Wars: The Roleplaying Game, Second Edition (credited for "original design")
- Tales of the Jedi Companion (credited for "Original Force Power Design")
- The Jedi Academy Sourcebook (credited, along with Greg Gorden, for "Additional Design" of the Force powers " Contort/escape ," " Force of will ," and " Shift sense ")
- Star Wars: The Roleplaying Game, Second Edition, Revised and Expanded (credited for "original design") His work on the initial release of Star Wars: The Roleplaying Game was honored with an Origins Award, recognizing it as the Best Role-playing Rules of 1987.