If you PK and get caught, you go to prison. Not killed by a super guard but hauled off to prison. We also have prisons scattered though the Unknown, with guards quite eager to fill them. Special items of which some are unique will be placed throughout the realm. Special weapons, staffs and wands also exist in various locations.
Magic plays a key role.
Certain monsters will cast spells, but so can you if you choose, depending on the path you follow. This is to make sure they remain known by only a few. Monsters have 52 additional spells. Spells are also broken up by alignment. An evil priest will not be able to cure people.