- Sword and sorcery adventure.
- Politic heavy.
- The world is in a state of constant war and chaos.
- The original D&D setting.
- First appearance of the Drow (with mustaches) and Thri-Kreen.
- Race Variants: Elf (Valley),
Greyhawk is set on the planet Oerth, which has an axial tilt of 30 degrees causing greater seasonal temperature variation than on Earth. One hemisphere of Oerth is dominated by a massive continent called Oerik. Over a thousand years of war, mad kings, enslavement and rebellion have left the world in a state of constant conflict and political negotiation. Humankind is fragmented into isolationist realms, indifferent nations, evil lands, and states striving for good. There are over seventeen regions with their own motivations, aspirations, and history of interactions with surrounding regions.
Castle Greyhawk was the most famous dungeon in Oerth, the home campaign world of Gary Gygax. Blackmoor was a country name on Oerth.