In variants where you can gamble away, sell, or otherwise lose your soul: a character who has lost their soul will get no more help from their god (until they manage to recover it). Sacrifices will be accepted but will never get rewarded with a gift; otherwise successful prayers will fail to give you shimmering-light invincibility, will go unanswered, and will give you no message as to the pleasedness of your god, and possibly you lose your divine protection as well.

You can enter into a pact with a single non-unique demon of your choice over the course of a game. This gives you significant benefits (varying and according to the type of demon) but also major disadvantages for the rest of the game. One major disadvantage for all demons is that it becomes much harder to be in good standing with your god.

Other examples of advantage/disadvantage pairings:

• A +8 damage bonus in exchange for being unable to become fast or very fast
• Being able to cast any non-healing spell in the game in exchange for no natural heath regeneration
• Maxing out an attribute in exchange for permanent reductions in your other attributes

Soul selling: when you summon a demon lord, there is some opportunity for you to sell your soul to them in exchange for a wish.

• Selling your soul both angers your god and suppresses all interaction with them.
• You may be able to recover your soul by killing the demon lord; for balance the demon lord should go far away when you sell your soul, though not out of the game.
• Alternatively, unless you wish for nothing (which makes the demon lord vanish forever), the demon lord will immediately become hostile, making it an unlikely tactic in the early game.
• Entering a temple without your soul will immediately anger the priest.
• Your quest leader won’t let you go on the quest while you are soulless.

You can make deals with demon lords (or maybe just one demon lord) for special abilities, but this has major drawbacks.

A demon lord who lives in Gehennom who you can sell your soul to in order to gain levels. This will have drastic effects on your score (or something) at the end of the game.