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->'' "Talk about being your own worst enemy." ''
-->-- '''Lara Croft''' in ''VideoGame/TombRaider'' [-(after sending a mutant copy of herself into a lava pit)-]

Doppelgänger, with an umlaut and a majuscule, is the German word for a ghostly double of a living person or more commonly simply a word for someone looking exactly like someone else, i.e. an impostor or double. It means "double (walker)", in the original. It is often said that one who sees their own Doppelgänger will die soon. In fiction, this is usually because [[KillAndReplace they kill you themselves and take your place]].

Traditionally, Doppelgängers have strange, supernatural origins, unlike twins which usually have more natural explanations. A MirrorUniverse, [[OurClonesAreIdentical Cloning]], alien intervention, and magic are all possible sources of a Doppelgänger. For purposes of clarity, this index includes both mundane and supernatural impersonators of a character.

For twins related by blood, see TwinTropes. See also DisguiseTropes. If a good character has an evil Doppelgänger, the Doppelgänger is an EvilTwin.

!!Specific types of Doppelgängers include:

* AlternateSelf
* AlternateUniverse -- self explanatory.
* ArtificialHuman -- [[OurClonesAreIdentical Clones]] and [[OrganicTechnology bioroids]] are one common way of making duplicates.
* BodySnatcher -- Doppelgangers created by bodily possession.
* ChangelingTale -- when TheFairFolk [[InvasionOfTheBabySnatchers abduct children]], they often [[RedHeadedStepchild leave behind]] a "changeling".
* CloneByConversion -- Being transformed into somebody else's doppelgänger.
* CostumeCopycat -- When a hero is impersonated by someone in a nearly identical costume.
* CriminalDoppelganger -- When the person's double is also coincidentally a wanted criminal.
* DeadPersonImpersonation -- When one person takes over another's identity.
* DifferentlyDressedDuplicates -- The person has been copied, but their clothes haven't.
* DoppelgangerAttack -- When one person makes multiple physical copies of oneself for combat.
* DoppelgangerSpin -- When one person makes multiple harmless copies and circle the target to distract them.
* EasyImpersonation -- When a hero is impersonated by someone in a not-even-similar costume.
* EvilCounterpart -- A character (not related to the hero) who is very similar, but ForWantOfANail turned evil.
* EvilDoppelganger
* EvilKnockoff - when a robotic duplicate or clone is made of a hero with the purpose of destroying them.
* EvilTwin -- When a character has an evil sibling or alternate reality duplicate.
** EvilBrunetteTwin
* FaceStealer -- When a villain has to harm another character in some way to look like them.
* FreakyFridayFlip -- When two people switch bodies, the result is remarkably doppelganger-like.
* {{Humanshifting}} -- A type of Shape Shifter that turns into humans.
* IdenticalGrandson -- SuperpowerfulGenetics is so strong, it can give you the original person back! (GeneticMemory also helps.)
* IdenticalStranger -- For some reason, the gene sequencing fairy took the day off and you have an unrelated twin.
* JekyllAndHyde -- When the person is their own doppelganger.
* LegendaryImpostor
* LiteralSplitPersonality
* MirrorSelf
* MySiblingWillLiveThroughMe -- When a sibling takes over a person's identity.
* OddballDoppelganger
* OppositeSexClone
* OurClonesAreIdentical
* ReplicantSnatching -- Or when a robot/alien peels off the original's skin and wears it.
* RobotMe -- When the doppleganger is a robot.
** MobileSuitHuman -- When the robot duplicate is piloted by a tiny alien.
* SeparatedAtBirth -- two (often but not always identical) twins are, well, separated at birth.
* {{Shapeshifting}} -- Some doppelgangers can do it by shape shifting.
* SplitAtBirth
* SurgicalImpersonation -- When the doppelganger used MagicPlasticSurgery to impersonate someone.

!!Related tropes:

* ActuallyADoombot -- When the person is revealed to be a robotic duplicate.
* AmbiguousCloneEnding -- Did the original kill the clone, or is the clone the survivor?
* BecomingTheMask -- What happens to many doppelgangers.
* BodyDouble
* CaptureAndReplicate
* CounterpartCombatCoordination -- fight your doppelgangers.
* CreepyChild -- often come in twos, or more.
* DistaffCounterpart: Very similar to the original character, just the opposite gender. Often a rival or villain.
* DoppelgangerReplacementLoveInterest -- That LoveInterest that just died? They have a duplicate in the real world that wants to shack up with you.
* EmergencyImpersonation -- An impersonator tries to fill in for someone else and HilarityEnsues.
* ExpendableClone -- The tendency to see these doubles as highly expendable, if not abominations to be killed.
* GenderedOutfit -- When an OppositeSexClone, DistaffCounterpart, or GenderBender wears an opposite-gender version of an established outfit.
* GlamourFailure -- Not all doppelgangers can hide their tells.
* ISayWhatISay -- Doppelgangers speaking in unison.
* IdentityImpersonator -- A ploy heroes use to throw off people are snooping their SecretIdentity.
* ImpostorExposingTest -- A test to identify an alien or supernatural impostor.
* ImposterForgotOneDetail -- An impersonator fails to to be convincing.
* KillAndReplace
* KillingYourAlternateSelf -- When doubles & alternates of characters meet. And then kill each other.
* MangledCatchPhrase -- One person imitates another but screws up the first person's CatchPhrase.
* MesACrowd -- when someone tries to clone themselves to do their chores.
* MirrorMatch -- When a character fights themselves (or a reasonably close match) in a video game.
* MirrorMoralityMachine -- A character is made into their moral opposite thanks to {{Phlebotinum}}.
* MirrorUniverse -- Home to many morality opposite versions of a cast.
* MistakenForAnImposter
* OpeningACanOfClones -- A story with clones, especially when used to revive dead characters or undo plot, makes the events lose punch.
* OtherMeAnnoysMe
* PrinceAndPauper -- Two people switch lives.
* ThePsychoRangers -- An ''entire team'' of doppelgangers to the FiveManBand.
* ScrewYourself -- Yes, there is PowerPerversionPotential to be had here (also RuleThirtyFour).
* SpotTheImposter -- When the friends of the impersonated have to figure out who the spy is.
* TeleporterAccident -- One surefire way to create a duplicate, evil or otherwise.
* TreacherousSpiritChase -- A malign entity poses as a dead loved one to lead the hero into peril
* {{Twinmaker}} -- A clone is made to replace a dead original.
* VillainsBlendInBetter -- Most villainous doppelgangers easily impersonate their target.
* YouAreWhoYouEat -- A non-human shapeshifts into the form of the person they've eaten.