Greg Costikyan, sometimes known as Designer X, is an award-winning game designer and author.

A graduate of Brown University, Costikyan worked on game design for many years, including writing and consulting for Nokia. His notable games include Web and Starship (a science-fiction board game), Toon (a humorous role-playing game), Star Wars: The Roleplaying Game (winner of the Origins Award for Best Role-playing Rules), Pax Britannica (winner of the Charles S. Roberts Award for Best Pre-20th Century Game), Paranoia (winner of the Origins Award for Best Role playing Rules), The Creature that Ate Sheboygan (winner of the Charles S. Roberts Award for Best Fantasy or Science Fiction Game), MadMaze, and Violence: The Roleplaying Game of Egregious and Repulsive Bloodshed.

Costikyan is a widely published author on the subject of game design and the role of games in culture. He has also written four novels, including Another Day, Another Dungeon and First Contract.

Costikyan was inducted into the Adventure Gaming Hall of Fame in 1999 and received the Game Developers Choice Awards’ Maverick Award in 2007.