World Tree Cosmology

The World Tree Cosmology is a now-common view of the cosmology of the universe that has been adopted by many scholars in modern times. This view of the cosmos likens their connections to a tree, with the prime elemental planes fueling the material plane and its mirror planes like roots of a tree, then branching outward into the outer planes like the branches. This view was first coined by the denizens of Argor in the 3rd century BA. It was a challenge to the commonly held belief that the planes of reality were largely unmappable. There is evidence that this view, while popularized by the largely human people of Argor, was originally developed by the elves of Eldheven, but due to the lack of written knowledge this cannot be definitively proven.

Mapping the Universe
The World Tree splits the planes of existence into 3 distinct regions. These are the Primordial Planes, the Material Planes, and the Outer Planes. Each is explained in greater detail below.

The Primordial Planes
The Primordial Planes are the roots, or foundation, of the universe. They make up the primal forces of creation, destruction, and the four classical elements. There are generally considered to be three primordial planes along with the cosmic river Seidre, which is fueled by these planes and envelopes the material planes in pure magic.

The Primordial Planes are:
 * Primordia, plane of elemental magic
 * Novos, plane of positive energy
 * The Void, plane of negative energy
 * Seidre, astral plane of magic (sometimes considered part of the material planes)

The Material and Mirror Planes
The Material Planes and their mirror planes are considered the trunk and main body of the tree. The Material Plane is not one solid mass, but is actually infinite pockets of reality swimming inside Seidre, the astral plane. Mirroring the prime material plane are three mirror planes, with the cosmic rivers of Styx and Somnia flowing through these mirror planes and affecting the prime plane through them. Styx flows out into the Outer Planes from here.

The planes of this section are as follows.
 * Elara, the prime material plane
 * Faenor, the mirror feywild
 * Arnyx, the mirror shadow plane
 * Atherom, the mirror ethereal plane (sometimes considered part of the outer planes)
 * Somnia, the river of dreams
 * Styx, the river of souls (sometimes considered part of the outer planes)
 * countless smaller material planes

The Outer Planes
The Outer Planes are not as understood and much more difficult to travel to than the other planes. They are considered the branches of the World Tree, and stretch out from the positive energy plane to the negative energy plane.
 * Thanis, land of the dead
 * Baator, prison fortress of Iblir
 * The Abyss, endless pit of demons
 * Arvandor, the wildlands
 * Valmora, the realm of the gods
 * The Maelstrom, endless chaos