In the World of Greyhawk campaign setting for the Dungeons & Dragons roleplaying game, Iuz (pronounced YOOZ or EE-uz) is the chaotic evil demigod of Deceit, Evil, Oppression, Pain, and Wickedness. Iuz is variously called "The Old One" and "Old Wicked," among other titles. Unlike most Greyhawk deities, Iuz makes his home on Oerth, where he rules a broad swath of the Flanaess known as the Empire of Iuz. Iuz was also named as one of the greatest villains in D&D history by the final print issue of Dragon. His symbol is a grinning human skull, or a human skull with blood-red highlights.