Doppelgangers primarily imitate player monsters and occasionally monsters that may be created by summon nasties. Each turn they have a one-sixth chance of attempting to change form; one-seventh of these attempts will turn them into a nasty and two-thirds of the rest will change them into a random player monster. Dopplegangers are considered human for sacrifice and cannibalism purposes.
Doppelgangers that are imitating player monsters will take the rank titles for that role, based on its level - a doppelganger imitating a fourth-tier Healer appears as a "Dresser", while one imitating an equivalent Wizard appears as a "Magician".
Doppelgangers are the source of a majority of player monsters that you will encounter in the main dungeon and other branches. As they are considered human, be careful not to sacrifice them unless you are a chaotic human, or eat them unless you are a human Caveman. Additionally, be wary of leaving their corpses around near carnivorous pets, especially hard-to-obtain ones such as purple worms.
The following information pertains to an upcoming version (3.7.0). If this version is now released, please verify that it is still accurate, then update the page to incorporate this information.Pets will no longer eat shapeshifter corpses unless they are starving or on the verge of untaming.
Doppelgangers first appear in NetHack 3.3.0.
"Doppelgänger" is a German word that literally means "double-walker", and refers to a biologically unrelated look-alike or double of a living person. The concept of alter egos and double spirits has appeared in the folklore and traditions of many cultures throughout human history.
In fiction, doppelgängers are often portrayed as ghostly or paranormal phenomena, and are usually seen as harbingers of bad luck; other traditions and stories equate a doppelgänger with an evil twin.
In SLASH'EM, doppelgangers are a playable race, with high stats, natural protection, and the ability to polymorph at will via the "#youpoly" extended command (which costs 20 power). Doppelgangers also benefit from polymorph changes in SLASH'EM, where killing a polymorphed monster reverts them to their base form instead.
"Then we can only give thanks that this is Antarctica, where there is not one, single, solitary, living thing for it to imitate, except these animals in camp."
"Us," Blair giggled. "It can imitate us. Dogs can't make four hundred miles to the sea; there's no food. There aren't any skua gulls to imitate at this season. There aren't any penguins this far inland. There's nothing that can reach the sea from this point - except us. We've got brains. We can do it. Don't you see - it's got to imitate us - it's got to be one of us - that's the only way it can fly an airplane - fly a plane for two hours, and rule - be - all Earth's inhabitants. A world for the taking - if it imitates us!
Xander: Let go! I have to kill the demon bot!
Xander Double (grabbing the gun): Anya, get out of the way.
Xander Double: That's all right, Buffy. I have him.
Xander: No, Buffy, I'm me. Help me!
Anya: My gun, he's got my gun.
Riley: You own a gun?
Buffy: Xander, gun holding Xander, give it to me.
Anya: Buffy, which one's real?
Xander: I am.
Xander Double: No, _I_ am.