Cosmology

The cosmology, or structure of the multiverse, is vast and extends far beyond the Material Plane that holds the world of Toril. Beyond the Prime lay many planes, which differ in size and shape. The exact structure of the universe has varied and changed over the millennia, the most recent change resulting from the Spellplague.

Overview
The planes of existence are different realities with interwoven connections. Except for rare linking points called portals the planes are, in effect, separate universes, each with its own set of natural laws and native creatures.

There have been numerous theories on the structure of the multiverse over the ages. The three major ones are as follows:
 * World Axis Cosmology: The post-Spellplague model.
 * World Tree Cosmology: The most commonly accepted pre-Spellplague Multiversal structure.
 * Great Wheel Cosmology: A popular alternative to the World Tree theory.

Anomalous Planes
Though most planes fall into the above categories there are some exceptions and not all planes have a clear place in the known cosmology. These planes exist in unknown, nigh unreachable places and only a few well-informed scholars know of their very existence. These planes may drift distantly in one of the fundamental planes or lie entirely outside of the World Axis or any of the other models. Perhaps because of their remoteness these planes often do not follow the same physical laws as do the other planes and are immensely inhospitable.

The known anomalous planes are as follow, though undoubtedly more exist:


 * Far Realm
 * The Far Realm is a distant and terrifying plane that lies "outside" of the rest of creation. This maddening realm is feared for its power to twist unfortunate visitors into gruesome monsters and it is from here that aberrations come.

Other Material Planes
Although it may seem otherworldly and strange it is a fact known to some that the Prime Material Plane within which Toril rests is not the only plane of its kind in all the cosmos. Other worlds have been recorded to exist, which lie beyond the local cosmology and outside of the crystal sphere that surrounds the Prime. Of these at least three are known.


 * Abeiran Material Plane
 * Although Abeir once operated in the same cosmology as Toril, the sundering split into a cosmological twin of the local multiverse at the time, with its own separate parallel and fundamental planes. Other than the fact that exists and that it occasionally interacts with the Prime, little is known of it.


 * Terran Material Plane
 * A world called Earth is located here, of which little is known but which was once visited by Elminster in the Year of the Prince, wherein he met with a scholar there named Ed of the Greenwood.


 * Oerth Material Plane
 * A distant world visited by Khelben Arunsun the Younger, Oerth differs enormously from Toril, being a geocentric world around which its sun and planets rotate.