Religion of Evil is a trope which involves a religion that is openly, unashamedly evil.
This usually belongs in the scope of fantasy religions (although the Game and Story usage section below gives some potential subversions) as very few people in real life are self-consciously evil.
The other major source of evil religions would be outright values dissonance where the host culture believes that the evil aspects of the religion are good and/or necessary.
A subdivision of this might be the various pseudo-Christian heresies that taught that God enjoyed forgiving sins, and so the more you sinned, the more fun He could have forgiving you. How much was genuine (if very poor quality) theology, and how much was excuse, probably varied quite a bit.
Game and Story Use
- Not very likely in real life, but they make very good villains.
- Most of the real life attempts at a religion of evil turn out to be groups of immature poseurs who delight in shocking and offending … and who are usually not as evil as they pretend to be. It's the ones who pretend to be the good guys that you need to watch out for…
- So a cult of wannabe evil believers could make a useful 'light relief' villain for a group of PCs (perhaps along the lines of 'The Trio' from Buffy the Vampire Slayer) - and once thoroughly discredited a good cover for the real villains. Also a good learning experience for excessively violent PCs, as tearing up a group of teenagers and their neckbeard mentors, even very obnoxious ones, is unlikely to win them much praise from anyone.
- Or as a slightly less comic version, the religion of evil could act as a false lead - when the PCs storm their hideout and find that the limit of their evil is playing FATAL and sacrificing stray dogs they can be left standing in the results of terrified incontinence wondering who the hell it was that did (whatever they are investigating) anyway…
- Many polytheistic religions will have one or more deities in the pantheon who are less than delightful and are more appeased than worshipped - a cult that actively venerates one of these might be an option, but in context a religion of evil might need to venerate an "enemy of the Gods" like Apep (Egyptian) or Tiamat (Babylonian) to fit the trope properly.
- The other option - especially in an authentic polytheism is a cult which focuses on worshipping a less benevolent aspect of a more mainstream deity. The cult of Zeus Lykaios - and its associated lycanthropy and cannibaism - might be a good example.
- The evil aspect of a dualistic religion is also a real possibility.
- Adventure seed: Fourth Biker of the Apocalypse