Oerth

Oerth is the name of the fictional planet on which the earliest Dungeons & Dragons setting - that of Greyhawk - takes place. Oerth has an axis tilt of 30 degrees, which results in larger polar caps and would have caused shorter summers in temperate areas but for wizardly and divine magic shifting weather patterns to be more favorable to the populace (at least the god-fearing folks).

According to the paper by Gary Holian in [Oerth Journal 4], Oerth's circumference is about 42024 km, and its radius measures 6714 km, about 1% more than Earth's. There is no flattening of the planet sphere due to rotation, and divine power is again hinted at.

Only about one sixth of Oerth's surface, that of the Flannaess is accurately detailed. Data on Aquaria and Hepnomaland are based on fanwork, and these continents are not officially supported by the game's publisher, TSR.

The name Oerth is similar to Aerth, the world of Jack Vance's novels, which in turn is an anagram of Earth.