"World of Darkness" (or WoD) is the name given to three related but distinct fictional universes created as settings for supernatural horror themed role-playing games. It is also the name of roleplaying games in the second and third settings. The first was conceived by Mark Rein-Hagen, while the second was designed by several people at White Wolf Gaming Studio, which Rein-Hagen helped to found. The first two World of Darkness settings have been used for several horror fiction–themed role-playing games that make use of White Wolf's Storyteller / Storytelling System, as well as Mind's Eye Theatre, a live action roleplaying game based on the core games. The third, Monte Cook's World of Darkness, created by Monte Cook based on the first two World of Darkness settings, includes only a single product.