A Metaplane is a realm of existence beyond our own, accessible only by magical initiates. Often referred to as the "higher", "inner", or "outer" planes, in actuality, they cannot be defined as existing in a three dimensional relationship with our world. They exist outside the physical plane.
Debate exists as to the exact nature of the metaplanes, most mages contend that they are real places, with some ascribing to the theory that they are merely a shared delusion. Another point of contention is the number of metaplanes. Some argue their number is infinite, while others say that there is actually only one, massive metaplane. It is known that six metaplanes correspond to six types of spirits;
Aside from the metaplanes reflecting spiritual or elemental states, there are also metaplanes that are unique in design and in function, if said metaplane has any. These metaplane can vary greatly; one metaplane may contain an endless, blasted and physically twisted plain to one that contains a single city that M.C. Escher could have designed.
Initiates have also traveled to a variety of metaplanes that correspond to mythical places, as well as some that are the likely origin of extraplanar threats;
- Avalon, the mythical home of King Arthur.
- Emergence Lake, the origin of the Navajo people in their creation myth.
- The Hive, the likely point of origin for insect spirits.
- Guinee, also known as The Land Beneath the Sea, home of the Voudou tradition's loa.
In addition to the domains of spirits and other unique places in the metaplanes, there are certain metaplanes that are normally not accessible to magicians. These areas are known as "Deep Metaplanes", and typically contain hostile "living" conditions and/or denizens. For example, The Hive is one of the few known deep metaplanes. In addition to housing the insect spirits, the deep metaplanes also play host to the shedim and the sinister "shadow spirits". If one accepts the Earthdawn/Shadowrun link as valid, then it is certain that the Horrors are located somewhere within the deep metaplanes.
It is possible to travel to a deep metaplane if one of these conditions are met:
- The initiate may be guided to a deep metaplane by a being that is native to the intended destination. Or, as an alternative, find an object or astral construct that gives an initiate directions on how to find that particular deep metaplane.
- An initiate may have access to and be able to use esoteric magical techniques to find and then travel to a particular deep metaplane.
- A magician (even a non-initiate) may be able to enter a deep metaplane if an astral rift opens up to one. This is not a common occurrence, however. The most widely known is the astral rift which opened on the site of Dunkelzahn's death.
If a magician enters a deep metaplane (or conversely, if a deep metaplanar resident arrives within Humanity's section of astral space), their astral form begins to degrade as they suffer from "Evanescence".