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.