Undead
The undead are once-living creatures from beyond the grave, now preying on the living or serving the dark will of Necromancers, unholy Priests, and certain evil gods. Examples of undead include skeletons, zombies, vampires, wraiths, ghosts, ghouls, and other horrors. They are common monsters in the Dungeon, and several undead species are available to players.
All undead are considered evil, and many gods award piety for destroying them. Naturally, Yredelemnul and Kikubaaqudgha reward their vile worshipers with power over the undead instead.
Undead traits
All undead beings (including player undead) share several immunities and vulnerabilities.
They have three levels of poison resistance, cold resistance 1, life protection 3, immunity to torment, and are not susceptible to mutations (they rot instead).
They are vulnerable to the Dispel Undead spell and weapons of holy wrath (which they also cannot wield).
They cannot berserk.
They are unable to use spells of self-transformation and those that only affect the living: Dragon Form, Ice Form, Spider Form, Statue Form, Stoneskin, Beastly Appendage, Blade Hands, Necromutation, Regeneration, Death's Door, Borgnjor's Revivification, Alistair's Intoxication, Cure Poison.
Being evil, the undead may not worship good gods: The Shining One, Zin, Elyvilon, or Fedhas Madash.
These are only the traits that all undead share. A particular undead being may have additional powers, intrinsics, and vulnerabilities peculiar to its species.
Playable undead
Undead species available to players are Mummies, Ghouls, and Vampires. Note that Vampires lose their undead traits when at full satiation or better.
Other species may temporarily become undead by casting the Necromutation spell.