Altar - Wikihack (old site): "Danger in sacrificingEdit
Sacrificing can be dangerous in the following circumstances:
Sacrificing at an altar not of your alignment type (ie. Lawful, Neutral, Chaotic) when your alignment is negative.
This may convert you to the altar's alignment, you lose 3 luck, and your prayer timeout increases by 300. Note that if this happens before you have been admitted to the quest, the game will be unwinnable.
If your god is angry with you, but your alignment is positive, you will not be converted."
'via Blog this'