Oerth

Oerth was a planet located in the center of Greyspace, a crystal sphere located in the Prime Material Plane.

Cosmography
Greyspace was part of a celestial configuration known as the Triad, which also included Realmspace, where the world of Toril was found, and Krynnspace, home of the world of Krynn. The phlogiston, a rainbow-colored chaotic liquid that surrounded the spheres, had a strong current that flowed from Realmspace directly toward Greyspace, making travel in that direction relatively simple; due to this current, it was impossible to travel directly to Krynnspace from Realmspace. From Greyspace, however, it was a relatively simple matter to travel to either Realmspace or Krynnspace, with strong currents leading to both spheres. From Krynnspace, one could easily move to Realmspace, but travel directly to Greyspace from Krynnspace was impossible.

Calendar
Similarly to Toril, the inhabitants of Oerth used a number of different calendars to mark the time. The standard most commonly used was the Common Year (CY) calendar. A year on Oerth lasted 365 days.

The marked the first meeting between Elminster and Mordenkainen on Earth. On Oerth, this was shortly before the year 581 CY, when Mordenkainen was beginning to suspect a plot to destroy the Circle of Eight, which culminated in Vecna's first failed attempt at becoming a greater deity.

History
In the mid‒14 century DR, Jewely Carseah and Marcus of the Waters were sent as emissaries from Oerth to the Rock of Bral to discuss the threat of invasion the Vodoni Empire posed to the crystal spheres of Realmspace, Greyspace, and Krynnspace, in the early stages of the War of the Spheres. The meeting marked the formation of the Free Space Alliance.

In the late 15 century DR, a book on the history of Oerth was part of the collection of the arcanaloth headmaster of the Dweomercore level of Undermountain.

Inhabitants
Oerth was home to prominent wizards such as Bigby, Drawmij, Tenser, and Mordenkainen, whose spells were well known on Toril. Mordenkainen was an acquaintance of Elminster's; the two had met on numerous occasions at Ed Greenwood's house on Earth to exchange spells and lore. Mordenkainen, when he had newly mastered interplanar travel, used to visit Waterdeep with some regularity.

When Harkle Harpell entered into an unorthodox contest of wizardry with the Sea Sprite ' s wizard Robillard, Harkle and Robillard mentioned a number of Oerthly wizards, including Bigby, Melf, Otiluke, and Tenser. In particular, Robillard regarded Bigby as one of the most powerful and impressive wizards of all time, on any world.

The Oerthly bard Gwydiesin of the Cranes also chatted with Elminster on occasion.

Both Elminster and Khelben "Blackstaff" Arunsun spent time on Oerth, and Elminster suspected that Khelben Arunsun the Younger settled there to begin a life away from the elder Khelben.

Appearances

 * Adventures


 * Under the Dark Fist • Waterdeep: Dungeon of the Mad Mage
 * Novels
 * Into the Void (mentioned only)