[[quoteright:300:https://static.tvtropes.org/pmwiki/pub/images/alice_and_bob.jpg]]
[[caption-width-right:300:Cartoon by John Richardson in ''Physics World'', March 1998.]]

When the interaction between two hypothetical characters is needed to explain or describe a trope, they are nearly always called Alice and Bob. Alice and Bob -- A and B. This duo originally started out as a standardized way to explain cryptography. Over time, the duo has been adopted in explanations of mathematics, physics, quantum effects, and other arcane places, but has also been seen in fiction.[[note]]They are also found in a surprising number of trope definitions. [[Administrivia/ExampleAsAThesis We're trying to get them cleaned out]]. Feel free to pitch in. This may be a doomed effort since many invocations are potholed to this page.[[/note]]

Where more than two characters are needed, other names are used, such as Carol or Charlie. If the two characters are the same gender, one of their names will be changed to reflect this, such as Alice changing to Alan or Bob changing to Betty. Some names have acquired standard meanings, such as Eve the Eavesdropper. Lists of these can be found in Bruce Schneier's book ''Applied Cryptography'', and over at [[https://en.wikipedia.org/wiki/Alice_and_Bob Wikipedia]].

Often makes use of AlphabeticalThemeNaming. See also ThoseTwoGuys, GreekChorus, MrSmith.

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!!Examples:

[[foldercontrol]]

[[folder:Films -- Live-Action]]
* ''Film/BobAndCarolAndTedAndAlice''.
* ''Film/HowToLoseAGuyIn10Days'' has a [[CoupleThemeNaming romantic couple]] of [[AlliterativeName Andie Anderson and Benjamin Berry]].
[[/folder]]

[[folder:Literature]]
* In most cryptography textbooks, communications are presented as being between Alice and Bob and must be secured from a third-party interloper named Eve (for Eavesdropper, of course!). If the problem requires the involvement of more than two parties, then Charlie and Donna may be introduced. This is the basis for the ''Webcomic/{{XKCD}}'' reference. Other character names sometimes used for special purposes include Mallory (a ''mal''icious active adversary, capable of changing the messages sent between Alice and Bob, whereas Eve merely listens), Trent (a mutually ''tr''usted third party, whom Alice and Bob might prevail upon to execute protocols in which they don't trust each other), and Peggy and Victor (the prover and verifier, respectively, in zero-knowledge proofs).
* Game theory books often use an adaptation of Alice and Bob -- "Rose and Colin" (rows and columns on game theory charts), with "Larry", or "layer", thrown in for three-person games.
* Game Semantics books tend to use Abelard and Eloise (for resemblance to the universal and existental quantifier symbols, which are an inverted A and a backwards E). They are also the names of a medieval logician and his lover.
* Alice and Bob are the names of the parents in Vernor Vinge's ''Rainbows End'', and a government official is named Eve Mallory.
* E. R. Emmet's "Our Factory" puzzles feature "Alf", "Bert", "Charlie", and so on.
* ''[[http://www.guidetojapanese.org/learn/ Tae Kim's Guide to Learning Japanese]]'': A free, online textbook, Alice and Bob are the main characters used in example dialogues and mock conversations, posing as foreign exchange students in Japan.
* ''Literature/AnotherNote''. the first generation of [[DoomedByCanon would-be successors]] to [[Manga/DeathNote L]] use the {{Code Name}}s (or rather, letters) A and B.
[[/folder]]

[[folder:Live-Action TV]]
* ''Bob & Carol & Ted & Alice''.
* One of the [[VanityPlate logos]] at the end of ''Series/TheBonnieHuntShow'' (2008-2010) is for "Bob & Alice Productions". Bonnie Hunt's parents are named Bob and Alice, so it is either just a reference to her parents or both.
[[/folder]]

[[folder:Music]]
* Nerdcore Rap artist MC Plus+ has a song about cryptography named "Alice and Bob".
[[/folder]]

[[folder:Newspaper Comics]]
* ''ComicStrip/{{Dilbert}}'' does this in a one-way fashion with "Ted TheGenericGuy", who has no consistent personality and shows up whenever a generic extra is needed. [[ButtMonkey Bad things tend to happen to him.]] His official bio notes that there may actually be multiple Teds, but nobody's sure.
[[/folder]]

[[folder:Oral Tradition]]
* "[[http://web.mit.edu/jemorris/humor/alice-and-bob The Story of Alice and Bob]]" is a humorous after-dinner speech recounting their mythology.
* There's a collection of [[http://web.archive.org/web/20060619074924/http://rogers.phy.bris.ac.uk/denzil/denweb4.html Alice and Bob jokes]].
[[/folder]]

[[folder:Video Games]]
* The ''VideoGame/DwarfFortress'' version is Urist [=McMadLibs=], with the "mad libs" part being descriptive; i.e. Urist [=McMiner=], Urist [=McVampire=], Urist [=McTantrumThrower=], Urist [=McUselessNoble=], and so on.
* Alice and Bob are the names of your guides in ''VideoGame/GameBuilderGarage''.
* Used in a very surreal CyberSpace level in ''VideoGame/WorldOfGoo'', called "Alice and Bob and the Third Party", where you intercept information goo transmitted from [-[=cosmicGrrrl!=]-] to [-[=LaconicCrusadr13=]-].
* Used as examples for an explanation of [[spoiler:quantum teleportation]] in ''VisualNovel/Remember11''.
* These are the default names of the main characters in ''VideoGame/HackNSlash''. Eve also makes an appearance.
* ''VideoGame/LiterallyEveryFNFModEver'' stars "Bob", a generic BlobMonster[=/=]MechanicalAbomination, who is used to demonstrate [[SequentialBoss the]] [[SpamAttack common]] [[DuelsDecideEverything tropes]] [[InterfaceScrew found]] [[NoBudget in]] VideoGame/FridayNightFunkin mods. Downplayed, though, as "Alice" is nowhere to be seen.
* ''VideoGame/Tekken6'' has Robert Richards, nicknamed "Bob", and Alisa Bosconivitch, with "Alisa" being the Russian equivalent of "Alice".
[[/folder]]

[[folder:Web Comics]]
* Parodied in ''Webcomic/{{xkcd}}'':
** [[http://xkcd.com/177/ 177:]] Eve tells her side of the story.
** [[http://xkcd.com/1323/ 1323:]] Computer scientists will listen to any boring story if the participants are Alice and Bob & co.
** [[http://xkcd.com/2691/ 2691:]] Solving the encryption situation in the most on-the-nose way possible.
* [[http://tropeoverdosed.byethost6.com/?p=6 The main characters]] of ''Webcomic/TropeOverdosedTheWebcomic''
* Alice is introduced in the opening chapter of ''Webcomic/FreakAngels''. In the epilogue, [[spoiler:she's explaining the story to a military officer named Bob.]]
* In Webcomic/RageComics, Derp and Derpina are the equivalent.
[[/folder]]

[[folder:Web Original]]
* There's actually a blog named ''Blog/AliceAndBob''.
* [[http://catalogliving.net/ Catalog Living]] has the imaginary Elaine and Gary.
* They (or rather, [[LegacyCharacter a number of male-female duos named after them]]) are the main protagonists of ''The Troperia Saga''.
[[/folder]]

[[folder:Real Life]]
* Alice and Bob really are quantum--a professor at the University of Washington has used two separate remote cameras, named Alice and Bob, to test the theory of non-locality and its potential for time travel, by attempting to receive a message before it's sent. The experiment hasn't yielded results so far, but it's telling.
* In {{UsefulNotes/linguistics}}, it's more often John and Mary.
[[/folder]]

[[folder:TV Tropes itself]]
[[index]]
* AccidentalMisnaming
* AcidRefluxNightmare
* AdaptationalAttractiveness
* AdaptationalSecrecyDowngrade
* AmnesiacLiar
* BathroomStallOfOverheardInsults
* BelatedHappyEnding
* BilingualBackfire
* BurpingContest
* CarRadioDispute
* CartoonishCompanions
* TheCatCameBack
* CelebritySurvivor
* ChaosWhileTheyreNotLooking
* CharacterizationMarchesOn
* CheatedDeathDiedAnyway
* ClassClown
* CoitusUninterruptus
* ConvenientlyCommonKink
* DartboardOfHate
* DeathByAdaptation
* DebtDetester
* DecoyProtagonist
* DelayedReaction
* DerailingLoveInterests
* DescriptionCut
* DidTheyOrDidntThey
* DidYouThinkICantFeel
* DinnerDeformation
* DivorceIsTemporary
* DontSneakUpOnMeLikeThat
* DramaticIrony
* EarPiercingPlot
* EasilyOverheardConversation
* TheExitIsThatWay
* ExplainExplainOhCrap
* FailedDramaticExit
* FanPreferredCouple
* FinishDialogueInUnison
* FinishingEachOthersSentences
* FootsieUnderTheTable
* FromMyOwnPersonalGarden
* GladIThoughtOfIt
* GlassesCuriosity
* HaveWeMet
* HeadTiltinglyKinky
* HoldingTheFloor
* HowMuchDidYouHear
* HurricaneOfExcuses
* IDidntMeanToTurnYouOn
* IdioticPartnerConfession
* ImColdSoCold
* ImStandingRightHere
* ImagineSpot
* IncompatibleOrientation
* IndulgentFantasySegue
* InvisibleStreaker
* IronicEcho
* JustWhistle
* KidsShouldntWatchHorrorFilms
* KissDiss
* KissingInATree
* KneelPushTrip
* LeaningOnTheFourthWall
* LetHimChoose
* LongDistanceRelationship
* LookBehindYou
* LoveForgivesAllButLust
* LoverAndBeloved
* MasterOfTheMixedMessage
* TheMatchmaker
* UsefulNotes/{{Mathematics}}
* UsefulNotes/MathCurriculum
* MemoryRestoringMelody
* MinorInsultMeltdown
* MistakenForDog
* MobileShrubbery
* MoreHypnotizableThanHeThinks
* TheMurderAfter
* MyFavoriteShirt
* MySecretPregnancy
* MySisterIsOffLimits
* NeverLiveItDown
* NoIAmBehindYou
* NoJustNoReaction
* NotListeningToMeAreYou
* NotSoInnocentWhistle
* NoYouGoFirst: Well, Alice and Carol, but Bob is Carol's boyfriend.
* ObliviousGuiltSlinging
* OperationJealousy
* OrAreYouJustHappyToSeeMe
* PatchworkKids
* PlaceboEurekaMoment
* {{Ponzi}}
* PreemptiveShutUp
* PrematureAggravation
* PropertyLine
* RaceForYourLove
* RapidFireInterrupting
* RapidFireNo
* RapidFireYes
* RescueRomance
* ResolvedNoodleIncident
* ReunionVow
* RevealingHug
* RightBehindMe
* RightInFrontOfMe
* SelfDemonstrating.SaidBookism
* SchrodingersPlayerCharacter
* SelectiveEnforcement
* SellingTheShow
* ShipperOnSet
* SingleTargetSexuality
* SnarkBall
* SoYouWereSaying
* StairsAreFaster
* Analysis.StoryBranching
* StrugglingSingleMother
* StyrofoamRocks
* SuchAPhony
* TacticalReminiscence
* TagTeamSuicide
* TakingTheHeat
* TamponRun
* TastesLikeChicken
* ThanksForTheMammary
* ThisIsNoTimeForKnitting
* TheThreeTrials
* TitleReadingGag
* TrappedAtTheDinnerTable
* TwinThreesomeFantasy
* VoiceoverLetter
* WalkInChimeIn
* WarShip
* WasItReallyWorthIt
* WhatIsThisX
* WhatsAHenway
* WhereDidWeGoWrong
* WhosOnFirst
* WhyAreYouLookingAtMeLikeThat
* WorstWhateverEver
* WoundedGazelleGambit
* SoYouWantTo/WriteAFilmNoir
* YesNoAnswerInterpretation
* YouCalledMeXItMustBeSerious
* YouKnowWhatYouDid
* YouWouldntBelieveMeIfIToldYou
* YouWouldntShootMe
* YourTelevisionHatesYou
[[/index]]
* Numerous PlayingWith pages.
* And more.
[[/folder]]
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