Oerth

Oerth is a world on the Prime Material Plane, known to some as the World of Greyhawk after a prominent city found there.

Oerth has four continents (Oerik, Hepmonaland, Hyperboria, and an unnamed southern continent), four oceans, and two moons (a silver moon called Luna and an aquamarine moon called Celene). There are some hints that it might have a hollow interior. Oerth exists at the center of a geocentric system and has seven planets beyond its moons and single remaining sun (Liga), as well as a dense spherical asteroid cloud called the Grinder.

Eight thousand years ago, Oerth had a technologically advanced civilization remembered only as the Doomgrinder Culture, but remnants of it exist only in small pockets today. Over ten thousand years ago, a planewalking civilization called the Crafters left the world. Eons ago, the Battle of the Plains of Pesh on Oerth decided the defeat of the armies of Chaos by the Wind+Dukes+of+Aaqa.

Oerth has hundreds of gods from dozens of pantheons and many associated Demiplanes and planar Portals. See Greyhawk Pantheon for more on that.

The people of Oerth generally see portals as something to seal up, especially after a major Tanar'ri incursion in the recent past nearly made the world a casualty of the Blood War.

Oerth has many grand claims for itself, boasting of being the homeworld of the Gith races and the elves, although there are other worlds with equally good evidence on both counts. Being the center of its system, Oerth imagines itself the center of the Multiverse, which makes it not unlike Sigil in that respect. Of course, there is no true center+of+the+multiverse.

Chant is, Oerth is dying, and the many gods and races of the world will have to find new homelands in the planes if they are to survive.