Canonfire! - Oerth Summary

An Overview of the Planet and Its Place In the Universe

Author: Scott Casper

Oerth Summary

by Scott Casper
Used with Permission. Do not repost without obtaining prior permission from the author.

The oerth is a planet, one of five extraplanar counterparts to planet earth, where powerful pantheons of gods maintain a vested interest, and the whole world is suffused with wondrous magics. It sits at the center of its own universe, held in place by the celestial mechanics, which make all the planets and stars circle it like clockwork. (1) The oerth revolves on a 30-degree axial tilt. Liga, oerth's sun, also revolves around Oerth, making it appear to take Liga 364 days for each complete circle of its orbit (along the path of a "corkscrew-like" orbit). (2) The length of one sidereal day is 24 hours. Liga is a golden sphere well over 2,000 miles in diameter, which burns hotter and brighter than any furnace, and orbits at a distance of 57 million miles from oerth. It has two moons, Luna and Celene, which lie between Oerth and Liga.

The oerth consists of the four elements - air, earth, fire, and water. The oerth is also spherical, with a diameter of just over 8,000 miles and a circumference of 25,200 miles. The surface area of the oerth is over 202 million sq. miles. (3) Oerth has four great continents, four great oceans, and countless islands and seas. The continents (from largest to smallest) are the following: Oerik, Aquaria, Hepmonaland, Telchuria (Hyborea). The oceans (from largest to smallest) are the following: Titanic, Solnor, Storms, and Drawmij. The average density of the planet is 172.4 pounds per cubic foot, averaging only 2.87 pounds per cubic foot on the surface. The planet exerts normal gravitational pull. The gravitational pull of the sun and moons does have a cumulative tidal effect on the planet, but seldom in a noticeable amount. Fireland sees the most distinct ones, with up to 45-foot tides. The planet's interior structure is broken into three spheres called the core, the mantle, and the crust. The pressure at the center of the core is 1.9 million atmospheres, but the pressure drops quickly to only 300,000 atmospheres at the outer boundary of the core. The mantle and crust are honeycombed with tunnels and caverns - some miles in diameter. Seismic activity has led to some oerthquakes over time, but Oerik in particular has few fault lines under it. The oerth has stable geomagnetic fields, providing a magnetic north that is identical with true north. There is some volcanic activity under the oerth, but most active volcanoes are magical in nature (caused by gates to the elemental plane of fire). Likewise, while continental drift is responsible for some oerthquakes, most tremors are caused by gargantuan burrowing monsters far beneath the surface.

Since antiquity, these facts have just been guessed at, or learned through divination. The history of the oerth is shrouded in such mystery that the gods encourage no creation myths in their religions. However, the oerth was in fact created some 200 million years ago by gods who predate those known today. The natural evolution of the planet was accelerated, and the native roster of species that evolved were supplemented with magical creations to suit the whims of those first gods.

1. Gary Gygax has refuted this claim, which was made "in character" in the World of Greyhawk Glossography (1983), but was rendered "canonical" by Greyspace (1992). I have retained the geocentric model, as it befits a fantastical setting.
2. The number of days was fixed from the start. The unusual orbit of Liga was established on the Greytalk listserv, circa 1998, to explain seasonal variation in a geocentric model.
3. Diameter, circumference, and surface area all come from Gary Holian's article, "Measuring Up the Oerth" (1996).

Cosmology, Spelljammer