Zork: The Great Underground Empire – Part I, later known as Zork I, is an interactive fiction video game written by Marc Blank, Dave Lebling, Bruce Daniels and Tim Anderson and published by Infocom in 1980. It was the first game in the popular Zork trilogy and was released for a wide range of computer systems, followed by Zork II and Zork III. It was Infocom’s first game, and sold 378,987 copies by 1986.