The legion of fictional deities in the World of Greyhawk campaign setting for the Dungeons & Dragons fantasy roleplaying game covers an extensive range of spheres of influence, allowing players to customize the spiritual beliefs and powers of their characters, and as well as giving Dungeon Masters a long list of gods from which to design evil temples and minions. Although the Greyhawk campaign world, when it was merely a home game, started with no specific gods, the value of having deities available for both players and game plot purposes was quickly realized. The number of deities has varied with each version of the campaign world that has been published, but for many years numbered a few dozen. It has only been since 1999 that the number of gods increased dramatically to almost 200, due to the volume of newly published material that was subsequently integrated into the campaign world.
Greyhawk as a home campaign: very few deities
When Dungeons & Dragons was developed in the early 1970s by Gary Gygax and Dave Arneson, one of the archetypal character classes in the original game was the cleric, a character who received divine powers from "the gods". However, when Gygax started to build his own campaign world called Greyhawk, one facet of culture that he did not address was organized religion. Since his campaign was largely built around the needs of lower-level characters, he didn't think specific deities were necessary, since direct interaction between a god and a low-level character was very unlikely. Some of his players took matters into their own hands, calling upon Norse or Greek gods such as Odin or Zeus, or even Conan's Crom in times of dire need. However, some of the players wanted Gygax to create and customize a specific deity so that cleric characters could receive their divine powers from someone less ambiguous than "the gods". Gygax, with tongue in cheek, created two gods: Saint Cuthbert—who brought non-believers around to his point of view with whacks of his cudgel —and Pholtus, whose fanatical followers refused to believe that any other gods existed. Because both of these deities represented aspects of Good, Gygax eventually created a few evil deities to provide some villainy.
In Gygax's serialized novella The Gnome Cache, which was set in Greyhawk, a shrine to St. Cuthbert (spelled "St. Cuthburt") is mentioned; this was the first published reference to a Greyhawk deity.
Greyhawk deities and the folio edition
In 1980, TSR published Gygax's home campaign world as a 32-page folio, World of Greyhawk (known as the "folio edition" to differentiate it from later versions). However, Gygax did not include any details of the deities he used in his home campaign at this time.
Several adventure modules were quickly published to support the folio edition, and one of them, C1 The Hidden Shrine of Tamoachan, featured the first deities designed specifically for a World of Greyhawk setting. The adventure was designed to introduce players to the Aztec-like Olman humans of the Amedio Jungle, a subject not covered in the folio edition. The Olman deities—largely drawn from Aztec culture—were Mictlantecuhtli, god of death, darkness, murder and the underworld; Tezcatlipoca, god of sun, moon, night, scheming, betrayals and lightning; and Quetzalcoatl, god of air, birds and snakes. However, Gygax did not acknowledge these deities in any of his work on Greyhawk, and TSR did not publish any further references or adventures using this setting, effectively "orphaning" the Olman culture. The Olman deities were not included in any versions of the Greyhawk campaign setting until they reappeared in 1999 in The Scarlet Brotherhood by Sean K. Reynolds and in 2005 in the extensive list of deities published for the Living Greyhawk campaign.
Lacking any Greyhawk-specific deities in the folio edition, many Dungeon Masters using the World of Greyhawk setting borrowed generic deities from the just-published rulebook Deities and Demigods for their Greyhawk campaigns. However, relief was in sight. In the August 1982 issue of Dragon (Issue 64), Gygax gave advice on how to adapt the 23 non-human deities from Deities and Demigods to the Greyhawk world, and he included a description of the first non-human deity designed specifically for Greyhawk, Raxivort (god of the goblin-like xvarts). A few months later, Gygax then published a long and very detailed five-part article in the November 1982 to March 1983 issues (Issues 67-71) of Dragon that outlined a pantheon of deities custom-made for worship by humans in the world of Greyhawk. In addition to his original Greyhawk deities, St. Cuthbert and Pholtus, Gygax added 17 more deities: