The Abyss

The Abyss is the Chaotic Evil Outer Plane

The Abyss is commonly understood to have "levels," which are in fact simply the demiplanes and shadowplanes that make up every planisphere. The difference is that the actions of Irazidun caused the various planes of the Abyss to become toroidal and polarized. The innermost ring of these planes, seen as a central horizontal line in the sky from the surfaces that look in, and the outermost ring, seen the same way from the outward looking aspects, are linked to the opposite polarities of other planes. Since momentum is preserved in an arc around the rings, something falling from the inside to the outside will fall around the ring, emerging on the inside of the next plane. Similarly, something falling the opposite direction will do the opposite. One must fly within 500 feet of the plane's surface to fall to its own gravity, or fly out past 500 feet to fall down the "abyssal well." Almost everything falls from the inside to the outside, giving that the illusion of orientation. Though objects in motion are weightless, they are not free-falling, but rather conserve their momentum in the orientation they are going. If they were to stop dead (something hardly achievable in practice) they would not move. Aside from this, the surface of almost all the planes observes the gravitational constant of the cosmos.

List of Levels of the Abyss:

Pazunia
Commonly mistaken as the "first layer" of the abyss as in the ordinal primier, it is in fact the chronologically terminal layer, or the plane from which the abyss was spawned. Pazunia, the home of Pazuzu, existed before the arrival of the Gods, as did the primordial Pazuzu. It is also the only plane that is not toroidal, but is in fact a sphere.