Conspiracy X is a role-playing game (RPG) that was initially published by New Millennium Entertainment in 1996. It has since undergone revisions and subsequent releases by various publishers, including Steve Jackson Games and Eden Studios, Inc. The game presents a setting where aliens are covertly infiltrating and exerting control over the world, drawing inspiration from the popular television series The X-Files.
The latest iteration of Conspiracy X is built upon the Unisystem, a role-playing game system. However, earlier versions of the game utilized the GURPS system as well as a unique system developed specifically for Conspiracy X.