Literally, this is a chasm of unfathomable and immeasurable depth; an infinite pit.
“The Abyss” is also frequently used interchangeably with the infernal regions or Christian Hell.
Abyss appears often in figurative speech as well. It has been used to describe youth and its uncertainties, the process of evolving and as a means of defining the situation or period of time through which an individual must travail, in order to attain personal growth.
The White wolf Inphobia contained a critical review titled "Planes of Chaos" by Keith H. The review described the Abyss to be one of the dangers of moving through the planes. This is especially so when it comes to characters of low and mid-level. They discovered that it is possible to create a situation in which the characters from the first level can achieve something very important so as to survive the Abyss. Notwithstanding that, the power and immensity of the planes is underrated most of the time. On top of that, it should be remembered that in the planes one must negotiate with the evil beings in a frequent manner. That way, the planes become important to the evil and neutral beings only.
The demons are the main race that inhabits the Abyss. These beings are very chaotic and evil in nature. Demons are of four types: the religion inspired demons which are associated with evil and sin; the classical, the ancient also called Lovecraftian Obyriths and finally Loumaras.
There are also other types of demons which cannot be specified in any manner. These do not belong to any other category as those outlined above. The categories we have shown above are known to host different types of demons. This means a large number of species classified under each category. The most influential and common species is called the Tanarri. These are the true rulers of the plane.
Manes is the name given to the petitioners or souls of the dead who have been posted to that layer for the case of afterlife. These are classified at the lowest part of the Tanar’ri demons.
They are characterized by sharp teeth, maggots crawling through their skin and white skin. Promotion to the higher level of demons depends on living for a long time. To become a Demon Lords, the manes must be extremely clever and live for a millennium or so. To illustrate that point, the Demon Lord Orcus, is a good example of one that started from being a mane.
Demon princes is another name for the Demon Lords. These demons are very powerful. In the Tanar’ri, there are a few Obyrith lords also. These demons make use of their influence and power to rule a whole layer of the Abyss. They are very powerful. Their great powers are equivalent to those of gods. They are known to command the smaller demons with a lot of efficiency.