Demon lord

Demon Lords (also known as Abyssal lords in 2E AD&D) are demons who have gained great power and established a position of preeminence among demonkind. Each demon lord has a unique appearance and set of abilities. Most control at least one layer of the Abyss. A demon lord, when slain in a plane other than the Abyss, is banished to the Abyss for 100 years, whereas "ordinary" demons, including the mightiest balors and mariliths, risk being reborn into a lesser form (or not all). The most powerful demon lords are demon princes. "Demon lord" and "demon prince" are self-proclaimed titles; unlike the archdevils, the chaotic evil demon lords do not have a rigid hierarchy.

Demon lords wage eternal war with each other, often seeking ways to expand their holdings into other layers and at the same time defend their personal domains from rival lords and scheming underlings. Demogorgon has for many years been the most powerful demon lord, and he proclaims himself Prince of Demons. Orcus and Graz'zt contest his title.

Most demon lords have secretive mortal cults who seek to elevate their lords to godhood through prayer and sacrifice. Book of Vile Darkness details a number of prestige classes for mortal disciples of demon lords, as does the "Demonomicon of Iggwilv" feature currently running in Dragon magazine.

Differences in D&D editions
The distinctions between demon lords and demon princes vary between editions of Dungeons & Dragons.

In AD&D, demon lords may not have complete sovereignty over a layer of the Abyss, whereas all demon princes rule one or more layers.

In 2E AD&D, both demon lords and demon princes are known as Abyssal lords. In 3E D&D, almost all demon lords control a layer of the Abyss, and many have a scattering of mortal worshippers, whereas all demon princes control at least one layer of the Abyss, and all have mortal worshippers.