been created to allow Gygax to adventure using his own PCs such as Mordenkainen. In 1975, TSR, Inc. published the Greyhawk supplement to the original Dungeons & Dragons rules, although this booklet provided no significant detail regarding Castle Greyhawk itself. Later on, Gygax developed the area around this new version of his castle and Greyhawk City to include new cities and countries as needed, expanding to a surrounding area of around 50 miles mapped in depth and approximately ten times that far in outline form by 1976. In 1978, TSR began publishing adventure modules set in the World of Greyhawk, although these early adventures did not directly concern the castle. Similarly, TSR's The World of Greyhawk 1980 folio and 1983 World of Greyhawk boxed set provided information regarding the campaign setting at large, but no detail regarding Castle Greyhawk. Between 1983 and 1985, TSR published three modules linked to Castle Greyhawk. These were the 1983 adventure Dungeonland and its sequel The Land Beyond the Magic Mirror, as well as 1985's Isle of the Ape. All three were originally conceived by Gygax as extra-planar extensions of the dungeons below Castle Greyhawk. As published, however, the modules again provided no information regarding the castle itself or its dungeons. The castle was first detailed for the general public in 1988 in TSR's adventure Castle Greyhawk. However, as the module was steeped in humor and featured numerous references to 20th century culture (such as the character the Amazing Drider-Man), most Greyhawk fans consider the module to be a "joke-version" of Castle Greyhawk. In 1989 The City of Greyhawk boxed set expanded on the detail available for the Free City of Greyhawk and its environs for the second edition D&D rules. The castle itself received only a minor mention. The castle finally received serious treatment in 1990, when TSR published Greyhawk Ruins, a 128-page adventure which examined the castle in great detail. In 2005, Troll Lord Games began publishing "Castle Zagyg" in a number of volumes authored by Gary Gygax and Jeffery P. Talanian. The Castle Zagyg series is written for the Castles and Crusades game, an OGL game derived from Dungeons & Dragons. These adventures are based on Gygax's original Castle Greyhawk dungeon design and campaign, but are not official D&D materials. In August 2007, Wizards of the Coast released Expedition to the Ruins of Greyhawk, a 224-page hardcover book that revisits the material