The Abyss is the realm of the damned, where those who commit terrible sins in life or die without a patron deity are sent to suffer for eternity. This supplement takes a look at the denizens of the Abyss and the depraved, black-hearted mortals who traffic with them. It is not an adventurers' guide to exploring the hellish realm or laying waste to its near godlike rulers. Nor is it a supplement of hard facts and absolutes. Instead, it presents a variety of commonly held opinions, any of which might be true.
Included inside are popular theories on the origin and nature of demons, descriptions of the various realms where sinners are sent, demonic magic, sample demon lords, and a host of new demons with which to terrorize the characters.