->"The name is the thing, and the true name is the true thing. To speak the name is to control the thing."
-->-- '''Creator/UrsulaKLeGuin''', ''The Rule of Names''

This is a version of FunctionalMagic that revolves around the use of "true names." A true name perfectly describes something's essential nature; knowing a true name gives one power over the owner of the name. In some portrayals, using a person's true name forces them to obey your commands. In others, a true name gives you a connection to the name's owner that allows you to work magic on them from a distance. Sometimes, a person's true name is needed if you want to work any magic on them at all.

In some stories, all creatures have true names, while others limit the use of true names to certain ''kinds'' of creatures, such as fairies, demons, or dragons. As a rule, objects do not have true names.

A person's true name might be self-determined, or bestowed on them by someone else--possibly in a religious or magical ritual. In works which feature true names prominently, people tend to guard them jealously, and will even have [[IHaveManyNames a second name]] (or two or three or more, depending on the character's age) for everyday use.

Audiences might think that having a very long or difficult-to-pronounce true name might provide one with a shield against being enspelled, but it never occurs to characters. Demons are an exception, with names that are frequently [[TheUnpronounceable impossible for humans to pronounce]].

However [[OutsideTheBoxTactic ingenious this tactic is]] to employ, [[ToWinWithoutFighting it's never always guaranteed to work]] and can [[MagicMisfire backfire spectacularly]]. A person's nature may be more [[HiddenDepths complex and hard-to-understand]] than initially taken for. They may compartmentalize or change their beliefs sporadically, thus invoking even their "True Name" is going to have very limited influence over them. [[SplitPersonality Mental illnesses]] are also a factor to consider and be wary of. The person in question may also be [[MoralEventHorizon so corrupt]], so insane, that their True Name has [[EmptyShell no meaning]] or [[TheSoulless significance to them]] anymore. On the other hand, announcing their real name may even damage them further, [[AwesomeButImpractical rendering them useless for controlling]].

Contrast SpeakOfTheDevil, where saying a name summons the named entity, but doesn't confer any power or control over it -- in fact, speaking said name may actually [[TheScottishTrope give that entity power over YOU!]]

Compare SympatheticMagic, where you need some other part of a person to work magic on them. Compare its related trope (and former title) WordsCanBreakMyBones, as well as LanguageOfMagic. See DoNotCallMePaul for the mundane, magicless version.



[[folder: Anime and Manga]]
* Inverted in ''Anime/ACertainMagicalIndex''. When sorcerers and magicians reveal their magic names, they gain an unspecified boost to their magical ability. One character who's a Saint refuses to do so until faced with the GodzillaThreshold of the Angel Gabriel wrecking havoc on earth, just because she's so scared of her own power.
* In ''Anime/AyakashiAyashi'', the protagonist can reveal the true name of anything he comes in contact with and use its power. The 'name' usually manifests as a tool of some sort, and is the most effective way to fight the monsters the heroes are meant to hunt down. Alternatively, destroying a Youi's name, will destroy the Youi itself.
* ''Manga/{{Bleach}}'': All races have powers that require knowing the true name of the attack to make it function at maximum potential, but true names are especially important for the Shinigami's [[TalkingWeapon Zanpakutou]], which cannot be unsealed without knowing the sword's true name. The sword also has a second name which is required for unlocking a second release of power. Dismissing the value and identity of a Zanpakutou is considered the height of ignorance, as both [[BattleInTheCenterOfTheMind Ichigo]] and [[TrainingFromHell Zaraki]] have learned. Also, one Shinigami ([[AlmightyJanitor Yumichika]]) lies about his Zanpakutou's true name to ensure his Zanpakutou [[BerserkButton refuses]] to reveal its [[MagicKnight true power]] so that he can fit in with his division's fighting [[BloodKnight philosophy]]. It is later revealed that the character Ichibei Hyosube gives everything in Soul Society its true name, including the Zanpakutou.
* The eponymous ''Manga/DeathNote'' requires that you write the true name of your intended victim, hence some of the characters using aliases whenever possible. The user is also required to know the face of the target.
** The definition of 'true name' beyond 'the name a shinigami's eyes see floating over your head' is not provided, but in the majority of cases it appears to be the legal name provided at birth. Meaning L apparently had fucking loonies for parents, unless he was named in unusual circumstances.
** Alternatively, one's 'true name' is simply the name people call themselves in their heads. For nearly everybody this is the legal name provided at birth; L may just have spent so much time [[spoiler:self-identifying as L]] that this is actually how he thinks of himself.
** Light does not appear to have lost too many marks to name changes, probably because he concentrated his efforts on persons already investigated thoroughly by the police, and Japan has a pretty tough name-record system in place with the family register. Modern record-keeping generally makes complete identity change much harder. A Death Note user in Japan a couple hundred years earlier would have had an interesting time working out which of a man's names was 'true.'
** Very minor, but the reason why a face must be known with the name was because the Death Note itself recognized that several people might have identical names, down to surnames, so you had to know the face of who you're writing down or else everyone with that name would all instantly drop dead. L managed to outsmart Light early with this by using the name "Hideki Ryuga", knowing that there's a famous Pop Idol with the same name and if he should happen to drop dead, it would mean Light is the culprit (L wasn't aware of the rules, but Light knew that even if Hideki Ryuga was his real name, the image of the pop idol might accidentally flash in his brain anyways, so Light couldn't even "test" it).
* The ''VideoGame/DevilMayCry 3'' manga says that a demon's name is so important to him that by taking it away, the creature can be sealed for eternity.
* In ''Manga/FruitsBasket'', Hanajima's brother Megumi claims to be able to curse people if he knows their names. Hanajima had warned the Yuki Sohma Fanclub representatives not to say their names in the house, but later Megumi reveals they did just that.
* PlayedForLaughs in ''Manga/HoushinEngi'' during a battle where the enemy's [[ImprobableWeaponUser Paopei was a megaphone]] that could freeze a person in place by shouting them to do so, as long as the user knew his target's real name. [[ObfuscatingStupidity Tai]][[CombatPragmatist koubou]] has fun with this.
* In ''{{Isuca}}'' the main character has the ability to reveal the true name of any magician and demon or otherwise supernatural being through… mouth contact. Yes, it's [[{{Ecchi}} that kind of manga]].
* True names play a big part in ''Manga/{{Loveless}}'' as they determine who your partner will be.
** When Soubi fights with Ritsuka he goes against his name since he and Ritsuka don't share names, which not only weakens their power as a whole but causes his name to bleed.
* Nodoka Miyazaki in ''Manga/MahouSenseiNegima'' requires at least a name for her [[{{Telepathy}} mind-reading]] book to take effect. Recently, with the help of a dungeon-crawling adventuring party, she's gained two NextTierPowerUp accessories (both supposedly useless, but {{Game Break|er}}ing in her hands): the ''auris lectans'', an ear-piece which immediately reads out words on paper to her mind, and the ''comptina daemonia'', which can read a target's name (in a sense) to her. While less powerful and discreet than the shinigami eyes, it's much cheaper.
** Also, at least one opponent, at the sight of the book, wondered if it was the Death Note.
** Interestingly, it has been revealed that one's True Name is the name that they ''think'' is their True Name. Also, if you name, say, any of [[SplitPersonality a person's multiple personalities]] and so on, it would still work. It gets kinda complicated regarding the specifics on true names and souls and all that.
* In ''Anime/{{Mononoke}}'' the name ("katachi" in the original Japanese, which also means 'form') of the mononoke is one of the three things the Medicine Seller needs to kill it.
* A central part of ''Manga/NatsumesBookOfFriends''. The main character owns a book filled with true names of spirits and is constantly accosted by spirits who want their names back or spirits who want to steal his book for themselves. Exorcist have to make contracts with {{youkai}} by giving them a temporary name for their partnership. It turns out [[spoiler: it is illegal to use the real name of ayakashi]] because their [[TheDarkArts fate is tied to the contract medium]], making the Book of Friends [[spoiler: [[DangerousForbiddenTechnique illegal as well]] ]].
* ''Anime/SpiritedAway'' has characters whose independence depends on them not forgetting their actual names. Chihiro is reminded not to forget hers (although the witch tries to take it away from her), and Haku is enslaved until he rediscovers his name late in the film.
** Worth noting is the fact that only one other character introduces himself without being prompted or hearing the name from someone else.
* In the ''Manga/VampirePrincessMiyu'' OAV, the DarkMagicalGirl must first learn the name of the Shinma she's chasing after and then use her [[PlayingWithFire flames]] in a spell that writes the kanji of said enemy's name in the air. Only then, she can seal the enemy away.
* In ''Manga/WildRose'', Mikhail knowing Kiri's true name, Kazekiri, is both proof he is his master and gives him total control over Kiri.
* This idea is enforced, expounded, and several other adjectives starting with 'e' by ''Manga/{{xxxHOLiC}}'', particularly by one of the main characters, Ichihara Yuuko. No, that's not her real name, and she [[spoiler: [[DeadAllAlong moves on]] before she ever reveals the real one]]. The series also deals a fair bit in WordsCanBreakMyBones. Incidentally, [[spoiler: the main protagonist's name, Watanuki, is also a false name, although [[TomatoInTheMirror he himself is not aware of it]] until far into the story.]]
** ''Manga/TsubasaReservoirChronicle'', due to it being linked to ''Manga/{{xxxHOLiC}}'' although it isn't stated here as explicitly. [[spoiler:Almost no main character actually uses their real name. [[SendInTheClones One set]] of "Syaoran" and "Sakura" are actually both named [[TitleDrop Tsubasa]], Fai's real name is Yuui, Kurogane's real name is Youou (or Haganemaru in the anime), and Mokona's real name is Soel.]]
** ''Manga/CardcaptorSakura'' once featured this when the only way she could seal the power of one of the Clow cards was to discover its name, given only the clues that it seemed to appear as a duplicate of Sakura, and that it held a relation to the Shadow, Water and Illusion cards. [[spoiler:"Like a shadow that mimics your moves. Like water that reflects your image. Not real, but an illusion.": the Mirror card]]
* Oddly inverted in ''LightNovel/{{Baccano}}''. Immortals are physically incapable of not revealing their true when another one is in the general area, but that's the only restriction their name puts upon them.
* The pharaoh in ''Manga/YuGiOh'' was unable to reclaim his world of memories from Zorc Necrophades until Yugi and the others learned his true name, [[spoiler:Atem]].
* In ''Manga/YuYuHakusho'', Roto is able to escape almost certain death by saying "[[IHaveYourWife I own your mother's life]]... Shuichi Minamino", and revealing that he has a demon able to kill Shiori Minamino if he so commands.
* In ''Manga/{{Monster}}'', the seemingly unstoppable Johan stops in his tracks when he finds out he can learn his birth name ("Johan" being a false name he adopted from a storybook he read when younger), long enough for his plans to incite everyone in a small town to kill each other to come crashing down and to get himself shot in the head.

[[folder: Comic Books ]]
* Variant: In ''Comicbook/TheInvisibles'', all new Invisibles take on a 'magic name' upon joining the organisation. This name is tied to their personality, and strongly influences their powers and lives (as poor Tom O'Bedlam discovered the hard way).
** Relatedly, in the same series, the English language has far more then 26 letters. Being knocked out is just the least of the possibilities with the new words.
* Franchise/{{Superman}} often encounters Mister Mxyzptlk, an imp from the 5th dimension who is sent back when he says his name backwards. As he's invulnerable otherwise, the only way to get him out of your hair is to trick him into saying his name backwards. Ever since the Creator/JohnByrne ContinuityReboot though this is nothing more than Mxyzptlk being sporting, as being truly untouchable by the 3rd dimension natives would be boring.
** Creator/GrantMorrison revealed in a storyline of ''[[Franchise/JusticeLeagueOfAmerica JLA]]'' that Johnny Thunder's Thunderbolt is actually a being from the same dimension Mr. Mxyzptlk hails from, and Johnny's old magical phrase ("Cei-U" or "Say You") used to call his Thunderbolt is in fact the being's name (Yz) pronounced backwards.
*** In the same storyline, a group of fifth dimensional imps reins in another by intimidating him into saying his name backwards.
** In the "ComicBook/EmperorJoker" storyline, the Joker tricks Mxyzptlk into revealing his "secret imp name", allowing the Joker to steal 99.9% of Mxy's power.
** In ''Action Comics #273'' (February 1961), Superman decides to pay Mxyzptlk back for his pranks by visiting HIS home dimension and playing pranks on ''him''. Mxy then tries to trick Superman into saying his name backwards (Namrepus) to send him back to Earth; when he finally succeeds, nothing happens, because unbeknownst to Mxy it isn't Big Blue's real name. After Supes has had his fun, he returns home by saying "Le-lak" ("Kal-el" backwards).
** In an episode of ''WesternAnimation/{{Superfriends}}'', they record Mxyzptlk saying his name and then play the recording backwards, which banishes him. For some reason.
** If [[OurBansheesAreLouder Silver Banshee]] knows a person's real name, then her [[MakeMeWannaShout scream]] will instantly kill them if they hear it. Because she doesn't know Superman's real name is Kal-El, her scream can only hurt his ears, much to her frustration.
** In one comic Superman tries this and it doesn't work because Mxy had his name legally changed.
* The justification for Libra being able to kick the ''[[Comicbook/TheSpectre Spectre's]]'' ass in ''Comicbook/FinalCrisis'' was that the Spectre didn't know Libra's True Name. Up to this point the Spectre was portrayed as an unstoppable embodiment of the Wrath of God (or the Presence, the closest thing to God in the DCU). Considering the shitty job Crispus Allen had been doing since becoming the Spectre, it's actually not all that surprising. Especially since Libra was working with... you know... [[AGodAmI Darkseid]].
** ''Final Crisis: Revelations'' instead implied the reason to be that Spectre only delivers justice to those God wants justice delivered to via him - he is the hammer of God. He smites what God wants him to smite. Libra's fate (and that of Darkseid) had apparently already been decided, and it didn't involve Spectre. [[AuthorsSavingThrow As a result, Spectre wasn't allowed to interfere with that particular issue.]] Either that, or since Evil won the war between the NewGods, Darkseid was dragging the entire multiverse into the Forever Pit and receiving massive amounts of [[VillainDecay Villain Anti-Decay]], at this point he had more power over the multiverse than God. Neither the Spectre nor the Radiant could feel God's presence at the time, despite being aspects of Him.
* In ''Comicbook/ElfQuest'', the telepathic Wolfrider elves all possess "soul names", the knowledge of which gives another elf access to the owner's most intimate thoughts and feelings. Therefore all Wolfriders guard their soul names carefully from all except their closest friends and lovers. However, the [[MindlinkMates involuntary mating urge]] called Recognition sabotages this by ''forcing'' the affected couple to exchange soul names. On one occasion BigBad Winnowill learned Dewshine's soul name and attempted to use the knowledge to coerce her, which only went to show how evil Winnowill was. On another occasion, Nightfall unilaterally gave her lovemate Redlance her soul name before placing herself in danger, so that if she died her soul would still be joined to his. She later brought Redlance back from the verge of catatonic shock by persuading him to give her his soul name, causing their souls to become one.
* This was a favourite trick of ConMan[=/=]Occultist Igor Bromhead in the ''ComicBook/{{Hellboy}}'' comics. Most memorably used in the "''Box Full of Evil''" storyline to enslave H.B.'s demon-cousin Ualac, and then to [[spoiler:paralyze Hellboy himself so they could steal his mystical Crown of the Apocalypse and [[RedRightHand Right Hand of Doom]]]]. It backfired, though, since Hellboy's "True Name", Anung Un Rama, means "World Destroyer, The Great Beast"--a role Ualac had just usurped from Hellboy by stealing his crown. When Hellboy realized this, Bromhead's hold over him was broken. Most recently, he used the true name of the human component in Hecate's replacement body to imprison her.
** Specifically in ''Box Full of Evil'', this is done thrice: first with Igor Bromhead commanding the demon Ualac using its true name, secondly with Bromhead commanding [[spoiler:Hellboy himself with his true name, Anung Un Rama]], and finally with Hellboy commanding Ualac using [[spoiler: his own name (Anung Un Rama, again) which had transferred to Ualac when the demon stole Hellboy's crown of fire]].
* It is mentioned in multiple issues of ''ComicBook/TheBooksOfMagic'' that names have power, particularly in the Otherworld of Fairyland. When the Manticore asks Timothy Hunter his name, the one he gives is "Jack Bone". In the original four-issue run, Rose makes the BabaYaga back down by claiming she knows her true name, and threatening to shout it to the world. [[spoiler: She's not bluffing.]]
** Tim also takes control of a clay golem by ''giving'' it a name, and drawing a face on it. His current companion, Leah, comments that such a thing is considered impossible.
* The Zombie Priest, BigBad of ''ComicBook/TheGoon'', can be controlled by anyone who knows his true name. One issue heavily implies that he's Literature/{{Rumpelstiltskin}}.
* The Elder god turned Demon Cthon, prior to leaving the physical plane, penned the [[TomeOfEldritchLore Darkhold]], the first book of magic ever written. He did it because "to name something is to hold power over it". As a result, Cthon effectively rules over ''all the magic of the Franchise/MarvelUniverse''.
* Reversed in the case of The Unnameable, a demonic entity from Creator/MarvelComics' ''ComicBook/TheDefenders'' series. Anybody who found out its true name fell under ''its'' control!
* The recurring EldritchAbomination of ''ComicBook/{{Hellblazer}}'' during Mike Carey's run was one of the animals that Adam never got around to naming during his time in Eden. And, as he never named it, he never gave it purpose, meaning, or definition -- leaving it to become shapeless, formless, and ever hungering...
** The incident in Newcastle that haunted Constantine for his entire adult life went wrong because the demon he and his friends tried to summon and control wasn't named what they thought it was. Years later, Constantine learns its true name [[spoiler: it's Nergal, who by now has made a few appearances without an overt connection to this part of backstory]] when the demon lets it slip during a monologue.
* ''Hawk & Dove'' #15 (1990) features a subversion of this. The protagonists find themselves stranded in Druspa Tau, a place of magic, different from their superheroic place of origin. There is a magical liquid metal called "tridic metal". It can be made to form any object the wielder can imagine but only if the wielder knows that object's True Name. One master does amazing things with the True Names of "staff" and "sword" and "morningstar" etc. Hawk? Figures out that if you know every last detail of an object, you don't need the True Name. So he picks up a blob of tridic metal and goes "''Trigger. Muzzle. Safety catch ...''"
* In ''PropositionPlayer'', Bill the Angel of the Lord claims that a whole slew of terrifying first-testament things will happen if his True Name was uttered, so he sticks with a simple nickname. It's never made explicit whether it's true or he's just bragging, though either is equally plausible.

[[folder: Fairy Tales]]
* In "Literature/{{Rumpelstiltskin}}", the title character offers to let the princess keep her firstborn child if she can guess his name within [[RuleOfThree three days]].

[[folder: Fan Fic ]]
* In ''[[http://randomactsofshark.blogspot.com/2008/01/barack-obama-and-thunder-zeppelin.html Barack Obama and the Thunder Zepplin]]'', Obama conjures the sylph Plame using her real name and offers her a new name in exchange for transport. This is a reference to [[http://en.wikipedia.org/wiki/Valerie_Plame Valerie Plame]], who had to leave the CIA after her name was leaked to the public.
* In ''[[http://www.fanfiction.net/s/4036084/1/ .hack//G.U.: The Staircase To Nowhere]]'', if an Epitaph user learns the true name of another Epitaph User, he/she can control their fellow user and make them do anything.
* In the EyrieProductionsUnlimited story ''Raven/The Demon Halloween Special'', after an "eventful" Halloween date between Comicbook/{{Raven}} and Comicbook/{{Etrigan}} (the aforementioned demon), realizing that he may be forced against his will again to do the will of the underworld, tells Raven his true name - giving her the power to stop him completely. (While this is certainly an effort to prevent him from being forced to commit any actions to which he personally objects, it is also an attempt to atone for his involvement - against his will - in just such an act when he kidnapped her on behalf of her father Trigon earlier.)
* Used several times in ''Literature/TheDresdenFiles'' fanfiction ''Fanfic/FairVote''. Exploited spectacularly so near the end.
* In a German TabletopGames fan comic, the [[RunningGag gay priest]] of a group converts a demon in order to free said demon from the evil mage who caught the group. Reason? With the conversion, he got a new name, and as you know, the control over a demon depends on knowing his true name.
* '''Very''' important in the ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' fanfiction ''FanFic/{{Eternal}}'', in which knowing and speaking someone's true name is essential to breaking past [[BecomingTheMask the masks]] certain characters have built around themselves. In dreams they are even more powerful and essential, but conversely ''mis''naming somepony, especially oneself, while in a dream is a recipe for disaster.
* One of Sakura's most critical power-ups in the ''Manga/{{Naruto}}'' fanfic ''Time Braid'' was discovering her own True Name. After all, if knowing someone's True Name gives you power over them, it only makes sense that knowing your own gives you power over yourself.
** Also happens in [[http://www.fanfiction.net/s/7183151/1 Vulpine]]. It turns out to be the true secret behind the Hiraishin. Minato back-asswarded his way into figuring out his own True Name via sealwork and then signed it on a summoning contract with himself, thus explaining why the Hiraishin never worked well for anyone else -- no one else has exactly the same True Name as he does.
* One ''[[Film/TheAvengers Avengers]]'' fanfic has Stark fall through the portal to the Norse underworld. A bridge to Asgard is guarded by Hel, who demands his name before she can lets him cross. After he gives it, Tony has an ''[[OhCrap oh crap]]'' moment as he recalls this trope, because "The brain reacts instinctively to the name it considers its own."
* In Fanfic/PokemonTheGreatAdventure, every wild Pokémon has a True Name that is given at its birth. Though it isn't really magical, only other Pokémon can know a Pokémon's True Name and having a human learn it without it being given is something they dread. On the other side, when a caught Pokémon willingly gives his True Name to his Trainer, it is considered the ultimate mark of trust. Ash knows the True Name of every Pokémon in his team, bar those he caught in the Orange Islands.
* At least one deity in ''Fanfic/DestinyIsAHazyThing'' forcibly got rid of it's true name in order to keep others from having power over it. However, this also made said deity considerably weaker since [[GodsNeedPrayerBadly prayers require a name to be truly effective]].

* In ''Film/TheATeam'', the CIA contact is known as Lynch, which it soon becomes obvious is a pseudonym, as various military figures recalls all the CIA agents named Lynch that they've known. [[spoiler:At the end, Lynch is calm as he's about to be led away and arrested, until Sosa reveals she has a warrant that's for Lynch's ''real name''. At that point Lynch goes straight into OhCrap mode]].
* ''Film/{{Warlock}}'', the MacGuffin is a book that contains the true name of God. Saying his true name backwards will cause TheEndOfTheWorldAsWeKnowIt.
* At the climax of ''Film/TeenageMutantNinjaTurtles'', when Splinter confronts the Shredder;
-->'''Splinter:''' Yes, Oroku Saki, I know who you are. We met many years ago...''[[YouKilledMyFather in the home of my master! Hamato Yoshi!]]''

* In Delia Sherman's "Grand Central Park," the main character plays truth or dare with the Queen of Central Park (a fairy). She asks the Queen to tell her her true name.
* In Creator/PoulAnderson's ''Literature/OperationChaos'', the narrator does not give his real name as a POW, only the official name he's using; when his daughter is born, affairs are more organized, and she is issued both a name she can use and a secret, real name.
* In Elizabeth Bear's Promethean Age series, names have power, as is demonstrated in the [[WhamEpisode Wham Chapter]] of ''Blood & Iron''; Elaine [[spoiler: gives her true name -- and her soul -- away, thus rendering herself [[{{immortality}} immortal]] and therefore capable as taking over as the ''Queen of the Faeries''.]] She occasionally still answers to the name, though; magic is magic, but you still need a way of getting someone's attention across a crowded room.
* In ''Literature/{{Tithe}}'', by Holly Black, Kay forces one of TheFairFolk to tell her his true name, not quite realizing that when she uses the name he has to do anything he's commanded to do.
** Specifically, Roiben promises to tell her any three things she asks. After he plays literal genie with her out of habit/to protect her ("Shall I consider that your second question?") she asks for his name to piss him off. She only knows that fairies don't like to share their names, and finds out WHY when she uses a [[LiteralAssKissing poorly worded insult]].
* This trope is referenced in ''Literature/AConnecticutYankeeInKingArthursCourt'' - the protagonist/narrator once fools the people into thinking he has done magic, by claiming to command an evil spirit by "thine own dread name" and then just making up a long nonsensical word.
* In Creator/JimButcher's ''Literature/TheDresdenFiles'', all sentient beings have a true name - in this case, it's their actual name, pronounced exactly as they say it. The more parts of their name you know, the more power you can hold over them. If you know their full name and can pronounce it correctly, you have a direct magical and metaphysical link to them. A doorway to their being, if you will. Of course, a doorway goes ''both'' ways. That's why Harry's BadassBoast mentions his name in full, and then adds the addendum that you should "conjure by it at your own risk."
** Harry meets [[spoiler: a Dragon named]] Ferrovax at a costume ball, and doesn't tell him his full name (going by just "Harry Dresden"). The incredibly powerful Ferrovax is able to force him to his knees with only the two names.
** Also, as the first book demonstrates, there ''is'' something more stupid than revealing your true name to your enemy: Letting him hear the true name of the demon you just summoned to kill him.
** Harry gives people nicknames. "Lash" ([[spoiler: Lasciel, the Temptress]]), "Ivy" ([[spoiler: the Archive]]), "Shagnasty" (the shapeshifter who feeds on fear), among many others. He even named [[spoiler: the Black Council]], and it probably isn't related in any way, but the only meaningful evidence to [[spoiler: their existence]] started showing up after he nicknamed them.
** Harry's habit of giving nicknames proves unexpectedly powerful as the names he gives them influence the very nature of beings like a skullbound spirit of intellect, the embodiment of all recorded knowledge, and the psychic imprint of a fallen angel. This somewhat backfires when he casually calls the archangel Uriel "Uri," and is told in emphatic terms to never do it again - that "el" is the part of Uriel's name that refers to God (the name as a whole means "Light of God" or "God is my Light") and he doesn't appreciate having it left off. There's also some FridgeHorror there: Harry ''has'' influenced things in part by giving them names, and it would be ''very bad'' if an angel as {{Badass}} as Uriel [[FallenAngel were to forget the "of God" part]] for even a minute.
*** Especially considering that other angel whose name prominently features something meaning "[[{{Lucifer}} light]]."
** Keeping one's names in reserve doesn't help when dealing with [[OurAngelsAreDifferent angels]]. Thanks to their ''intellectus'', they automatically know the True Name of anyone they're dealing with, letting them flatten any mortal who tries to stop them from completing their tasks.
* Ted Chiang's SF short story ''Seventy-Two Letters'' uses this trope as one of its themes. In the story scholars engage in research to discover new names to give to clay golems that will imbue them with the ability to perform various tasks.
* In Meredith Ann Pierce's ''Literature/TheFirebringerTrilogy'', knowing someone's true name doesn't necessarily give you complete power over them - it just makes them a lot more vulnerable to other spells.
* In Creator/GlenCook's ''Literature/BlackCompany'' series, saying "I name your name, ______" with the person's True Name will strip them of their supernatural powers. Guessing wrong about which ancient wizard you're naming can be hazardous to your health...
** This is also why the most powerful sorcerers in the setting are universally {{Evil Sorcerer}}s. Any magic-user not willing to suppress his true name by [[KillEmAll any means necessary]] will not remain a magic-user for long.
** The only good wizard of sufficient power in the series is able to do so because, as the result of some peculiarities at the time of his birth, he has no true name, only a nickname.
* The ''Literature/WizBiz''/''Wizardry'' series by Rick Cook; this also semi-averts people not realizing the best protection, as the hero is [[TrappedInAnotherWorld from another world]] and after a near-brush with revealing his true name, ''only'' goes by two different convenient nicknames. Other wizards also go by a nickname, or only a portion of their name, for the same reason.
** This comes in particularly handy when a bad guy sics an [[OurDemonsAreDifferent ultra-powerful demon]] onto the hero; said demon is dangerous because it can hunt and kill anyone whose name has ever been spoken in that world. This would be a perfect plan except for the "from another world" thing.
* Creator/DianeDuane's ''YoungWizards'' series has the wizardly Speech as the LanguageOfMagic. Knowing someone's true name does ''not'' let you control them, but it is needed to perform some types of spells on them. Wizards must "sign" spells with their name in the Speech, which comprise not only spoken names but personality and sense of identity. And writing the name of something differently in the Speech changes the thing so named, so they must be treated with extra care.
** Nita exploits this in the climax of ''So You Want to be a Wizard'' when she's reading from ''The Book Of Night With Moon'': [[spoiler: she rewrites the last character of [[{{Satan}} The Lone Power]]'s name so instead of being trapped as evil forever, he has the option to [[HeelFaceTurn turn back]].]]
** Another example occurs in ''A Wizard Abroad'' where to repay a debt, one of [[TheFairFolk the Sidhe]] whispers what is presumably his true name to Nita, instructing her to speak it to call for aid one time if she needs it. It comes in handy when they encounter creatures that are [[AntiMagic immune to their spells]] and speaking it calls out said fey and TheCavalry (literally).
** All of the words in the LanguageOfMagic are the true names of the things they stand for. Which makes sense, since it was the language with which reality itself was written.
* The ''[[Literature/TheTaleOfTheFive Door]]'' series, also by Diane Duane, also uses the trope. People have powerful, secret true names, though most don't know what theirs is.
* At one point in the ''[[Literature/TheBelgariad Malloreon]]'', Ce'Nedra was possessed by Zandramas. Polgara forces Zandramas to admit her name, and by doing so is able to banish her. Polgara mocks Zandramas for "not knowing the power of a name."
** It eventually becomes apparent that Polgara was ''lying'' about this. Zandramas is better at messing with minds than Polgara is at spotting her, but is aware of her inferior education and (relatively) enormous inexperience, and is inclined to run in any direct confrontation. Polgara's bluff played to this.
** Eddings also played a different version of this game in the ''Literature/{{Tamuli}}'', in which the Child Goddess Aphrael speaks the true name of the Elene God to Patriarch Bergsten, to prove that she's ''not'' a demon.
* In Creator/MichaelEnde's ''Literature/TheNeverendingStory'', the Fantastica side of the plot begins with the Childlike Empress getting sick because she "needs a new name." Bastian becomes a Fantastican hero because he has the ability to name things. This is natural, as words have obvious importance when the entire world exists in a story.
** In the second [[Film/TheNeverendingStory film based on the book]], Bastian is called back to Fantasia in order to name the new threat ("The Emptiness") which should give them the power to fight it properly.
* Creator/DianaWynneJones:
** According to ''Literature/TheToughGuideToFantasyland'', avoiding this is the real reason so many Fantasylanders have [[PunctuationShaker apostrophes in their names]].
** In ''Literature/TheDalemarkQuartet'' books, saying the lesser name of one of the gods causes an island to come up out of the sea and break your enemy's ship in half. "What happens if you say his big name?" [[spoiler: It causes a tsunami... even if you're miles from the sea.]] Unsurprisingly, he's known by his nickname, the Earth Shaker. His wife's names also have dramatic effects.
** In ''Literature/PowerOfThree'', a major threat to the Dorig and Lymen is to simply mention that one has the name of an enemy in mind, as having a person's name allows you to curse them. Ceri scoffs at the 'giants' for giving out their names so freely.
* Katharine Kerr's ''{{Literature/Deverry}}'' sequence, where it applies to [[OurDragonsAreDifferent dragons]].
* Creator/UrsulaKLeGuin's ''[[Literature/EarthseaTrilogy Earthsea]]'' series is probably the TropeCodifier. Each person is given his or her true name (which is a word in the language of dragons) by a Wizard. People keep their true names secret, and have other names for common use. A woman who lost her true name was rendered semi-catatonic. It is implied by the books that one can't be given an unpronounceable true name.
** In one of her short story precursors to the series, "The Rule of Names", two supposed wizards get into a battle that involves lots of shapeshifting. The wizard Blackbeard invokes this when his opponent turns into a dragon, naming him and forcing him into his true form. Turns out [[spoiler: the opponent's true form ''is'' the dragon. Blackbeard is promptly eaten.]]
** And it's not just people that have names; everything, from rocks to trees to sheep to the earth(sea) itself has a name, and can be controlled by one who knows it, thus allowing {{Reality Warp|er}}ing. Unfortunately, [[RealityWarpingIsNotAToy said control affects EVERYTHING that shares the name]], as shown by the story of the man who accidentally turned an ocean of saltwater to fresh, when he only wanted a section of it to change. He was [[FateWorseThanDeath cursed]] by the gods to endlessly shovel the deposited salt back into the ocean, without being able to die.
** And different parts of things have names. The whole ocean is a name. The western ocean has a name. This bay has a name. This shoreline has a name. Being a powerful wizard means being a walking dictionary of true names. Being a research wizard means using many tricks to learn true names.
* ''Literature/AWindInTheDoor'' by Creator/MadeleineLEngle does not treat names themselves as being important, but the very ''state'' of being Named and of having someone know your Name is extremely important (as the cherubim Proginoskes put it, "He calls them all by name, and someone has to know who He's talking about.") This is the job of Namers, because without being Named, a person cannot know who they are, and are vulnerable to someone else pushing them around. The secret to naming? [[ThePowerOfLove Love.]]
** Reversed by the Echthroi, the closest thing L'Engle had to monsters: they can "X" a person, [[FateWorseThanDeath un-Naming them]]. [[spoiler:Echthroi can be "rescued" from their state by Naming them.]]
* In ''[[GentlemanBastard The Lies of Locke Lamora]]'' by Scott Lynch, mages can mentally puppeteer anyone whose true name they know. The Bondsmage finds out the hard way that [[spoiler: Locke Lamora is ''not'' the protagonist's real name.]]
* Creator/PatriciaAMcKillip:
** In ''Literature/TheBellAtSealeyHead'', when Ridley Dow is caught in the magic, Emma's calling "Mr. Dow" does not lead him to the CoolGate, but Miranda Beryl's use of [[FirstNameBasis "Ridley"]] does.
** In ''Literature/TheForgottenBeastsOfEld'', Sybel must learn the true names of her beasts to bind them to her. This also proves to be her own point of weakness.
* In Creator/RobinMcKinley's ''Literature/{{Sunshine}}'', [[OurVampiresAreDifferent vampires]] use name magic. One laughs at the narrator for asking him his name, and later reveals it as a gesture of trust. Unlike most works, in ''Sunshine'', the name is the name -- or names -- you use. The narrator is as vulnerable through her nickname "Sunshine" as through her name "Rae," and more vulnerable through either of those than through her long-disused birth name "Raven Blaise."
* ''TabletopGame/{{Warhammer 40000}}'' has many examples, so naturally so does its literature segment:
** The ''HorusHeresy'' novel ''False Gods'' has Temba whisper Horus's name to his [[CoolSword warp-tainted sword]], before fighting with new skill.
** In the later novel ''Prospero Burns'', a demon is able to control all the Space Wolves present by pulling their names from Kaspar Hawser's brain. Only one marine, called Bear, is immune to the control. When Hawser later asks why the demon couldn't control Bear, he learns that the demon pulled the names from his mind, and Hawser's gotten Bear's name wrong from day one. Bear's name is actually ''Bjorn.''
** Zygmunt Molotch, the villain of the ''Literature/{{Ravenor}}'' series, can subdue an opponent by speaking their full name using a Chaos skill called "Enuncia". (He can also briefly stun them using less than their full name, but this is much less effective.)
*** Toros Revoke, of the same series, is much better at using Enuncia as a weapon. He's able to shatter bones, burst internal organs, and drive back a daemonic assassin using it.
** In ''Literature/GreyKnights'', [[spoiler:Ligeia]]'s gibberish is actually the True Name of [[spoiler:Ghargatuloth]], and [[spoiler:Alaric is the only one to realise this.]] It pays off.
** Saying the name of a greater daemon while in its presence will send them instantly back to the warp. Their ''true'' name, mind. If a greater daemon of Khorne says its name is "Bob", it's probably lying.
** [[ExactlyWhatItSaysOnTheTin The Grimoire of True Names]]. Incredibly rare and potent artifacts, guarded by the Daemonhunters (who else?). In the ''Grey Knights'' novel, [[spoiler:Ligeia]] finds such a Grimoire - known as the ''Codicium Aeternium'', thought to have been lost for centuries - after the capture of a rogue Inquisitor, which sets the Grey Knights off on the quest featured in that book.
** In ''The Unremembered Empire'', a daemon tells its true name to Damon Prytanis just before it goes to kill him, believing that it already knows his true name. [[IdiotBall It didn't stop to think that Prytanis wasn't his real name]].
* One series where the wizard ''does'' have a huge, unpronounceable name is Creator/LarryNiven's ''Literature/TheMagicGoesAway''.
* Creator/AndreNorton
** In ''Literature/WitchWorld'' novels, name magic is routine, and so powerful than the witches of Estcarp hide them from everyone.
** In ''Literature/DreadCompanion'', Kilda is saved from being hunted by a creature that calls the name of the hunters. Later, he tells her that they must obey their names, it is the law.
* In Scott O'Dell's ''Literature/IslandOfTheBlueDolphins'', the protagonist's father accidentally introduced himself to the captain of the hunters' ship using his secret name rather than his common name. He later fell in battle, and his people blamed the public use of his secret name for it.
* In ''The Gift'' by Patrick O'Leary, dragons can be commanded by their true names… except that, as it turns out, they all have the same one (the ancient word for "dragon"). They were purposely conditioned that way centuries ago by wizards who wanted to keep them in line.
* In Christopher Paolini's ''Literature/InheritanceCycle'', knowing the true name of someone lets you control them. They also have Elvish as a LanguageOfMagic.
** It's said that by finding out the name of the Ancient Language, a spellcaster would be able to change the meaning of words and essentially have complete control over magic in the world. In the final book, [[spoiler:Galbatorix finds out the name, and explains how he plans to use it to [[TheMagicGoesAway stop anyone from being able to use magic again.]]]]
** Also, this is a case of every animal/object having a true name. Though the only example thus far has possibly been [[spoiler:Eragon's sword (It's name translates as 'fire' and when Eragon says that word in the LanguageOfMagic, it [[FlamingSword bursts into flames]] as if he had cast a spell.)]]
** Also, a person's True Name isn't set in stone. As they grow and mature, and their personality changes, their true name will also change to reflect this. This can come in handy, since if someone is using your true name to enslave you, you can escape by changing yourself enough for your name to change. It isn't easy, but it's possible.
*** It also has a more mundane use. If you find your own true name, it can act as a form of magical self-introspection that enables you to understand every aspect of yourself at once, the good and the bad. While this might be seen by some as a bad thing, it's portrayed as positive since it enables you to accurately assess your faults and find where you have room to grow.
** [[BigBad Galbatorix]] combines the ability to control someone through their True Name with the fact that the Ancient Language is a LanguageOfTruth to force people to swear unbreakable oaths. [[spoiler: [[NotSoDifferent As does Eragon.]]]] Galbatorix also cast a spell so that anyone who attempts to use his True Name against him will die.
* In Creator/BarbaraHambly's ''Winterlands'' series (that begins with ''Literature/{{Dragonsbane}}''), everything, even inanimate objects, have true names. Any spell stronger than basic telepathy (which can be used to discover someone's true name) requires you to Know Your Target's True Name, and you have to power the spell by "sourcing" [[{{Mana}} energy]] from things you know the true names of. [[OurDragonsAreDifferent Our Dragons Are Immune To Magic]] because nobody can figure out what their true names are. [[spoiler:It turns out that dragons' true names are MagicMusic.]]
* In Creator/TerryPratchett's ''Literature/{{Discworld}}'' novel ''Discworld/{{Mort}}'', it's briefly mentioned that, in the old days, students at [[WizardingSchool Unseen University]] had to "memorise the true names of everything until the brain squeaked". It's not made clear that there's any magical advantage to doing so, however. Considering the attitudes of the Unseen University faculty, it's quite likely that most of the 'learning true names' curriculum was to keep the students too busy to bother them.
** In ''Discworld/TheLastContinent'', it's stated that the Librarian has removed all mention of his own name from University records to prevent anyone trying to turn him back into a human. Rincewind knows it, and so the Librarian dissuades him from telling anyone -- by holding him over a ''ten-story drop''.
** In ''Discworld/{{Pyramids}}'': "All things are defined by names. Change the name, and you change the thing. There is a lot more to it than that, but paracosmically that is what it boils down to..."
** A slight variation involves the fact that ''giving'' a name to something changes its nature, as in ''Discworld/InterestingTimes'' (with regards to Magitek Hex) "We should never have given you a name. A thing with a name is a bit more than a thing." Also comes into play when Agnes names her alter ego Perdita. She then develops a magical form of multiple personality disorder, as Perdita becomes an actual person living in Agnes' head with her and being everything Agnes wishes she could be.
* Similarly used in ''Literature/GoodOmens'' where the AntiChrist, having been accidentally brought up by a normal middle-class family, is sent a Hellhound. The Hellhound has a bit of internal monologue all about "The Naming", saying that its master's name will give it its purpose. When said Hellhound is simply named "Dog" since that's all the boy wants, however, it ends up becoming... [[ExactlyWhatItSaysOnTheTin a dog,]] and all that the name implies. It's a happy-go-lucky, cat-chasing, normal, everyday dog.
** Pepper's proper name is Pippin Galadriel Moonchild. "There are only two ways a child can go with that name, and Pepper had chosen [[{{Tomboy}} the other one]]."
* Creator/SpiderRobinson once wrote of a wizard so ancient that he guided the evolution of humanity in such a way that modern larynxes simply can't form the sound of his True Name.
* In Emily Rodda's ''The Key to Rondo'', giving the Blue Queen your true name gives her power over you, and she can command you to do anything, up to and including suicide. In her first appearance she gains control over the heroine's beloved dog through this means; however, she doesn't gain control over the heroine, first because she believes the heroine to be someone else (and thus uses the wrong name), and then because the hero knows the heroine only by a nickname and therefore, despite calling her by her name repeatedly, doesn't reveal her real name.
** In the final showdown, the Blue Queen learns the hero's name, and controls him as a hostage from that point on, effectively removing him from battle and threatening his life for a FriendOrIdolDecision.
** In the third book, ''The Battle for Rondo'', it's how they managed to defeat the Blue Queen. [[spoiler:After Leo figured it out and tried to use her true name, Indigo, to stop her, the Blue Queen rejects it and suffered for it.]]
** In another of Emily Rodda's books, Deltora Dragons, the dragons believe that knowing a fellow dragon's name gives you some type of power over them.
* Jonathan Stroud's ''Literature/TheBartimaeusTrilogy'': Magicians lose their names when they start training and choose new ones to be called by later on.
** Unfortunately, unlike most examples, this still doesn't work -- the new names aren't nearly as powerful as their birth names for magical purposes, but can still be used to mess with them.
** Demons are also summoned and controlled through their names, though its revealed that this is less because it's their true name, but that when a magician first summons a demon he gives it name, and that name can then be used to call them. Bartimaeus and many other demons also [[IHaveManyNames have many names]], but only Bartimaeus actually seems to have power over him.
* Although no specific reason is given, The Ents in ''Literature/TheLordOfTheRings'' are likewise surprised at people giving out their real names, though the long-winded Entish language probably makes it [[{{Pun}} moot]] for them (an Ent's true name can go on for days). Gandalf also complains that Bilbo was smart enough not to tell Smaug the dragon his name, but could have avoided rather more trouble if he hadn't told Gollum.
** While not exactly magic, calling Sméagol/Gollum by one name gets a very different reaction than calling him by the other.
** The protagonists also rarely speak Sauron's name out loud, usually using his title "Dark Lord", instead. Though it isn't explicitly stated, it's implied that speaking it too often in wrong situations could make him aware of the speaker. Also, when Pippin uses a Palantír and accidentally makes contact with Sauron, the first thing the Dark Lord does is demand his name, which Pippin refuses despite the resulting mental torture - again, it's implied that telling your own name to Sauron could make you fall under his power.
** Tom Bombadil teaches Frodo Baggins an extended verse which will bring Tom to the aid of anyone within his territory who utters it, and this verse includes his name.
** Dwarves in Tolkien are [[AllThereInTheManual described as]] having true names in Khuzdul, which they never reveal, not even on their gravestones. The names they are known by (Thorin, Balin and so on) are by-names.
* ''Literature/TheChroniclesOfAmber'' series by Creator/RogerZelazny, in ''Guns of Avalon'', when Strygalldwir comes to Corwin's window. He offers his name but says "Conjure with it and I will eat your liver." Only seems to apply to that certain brand of demon, though.
* In ''The Changing Land'', also by Creator/RogerZelazny, one of the characters is a demon named Melbriniononsadsazzersteldregandishfeltselior. Usually conjurers trying to summon him messed up his name during the summoning and binding ritual - which left the demon free and ready to have fun. Unfortunately for the demon, another character, wizard Baran, was from a land with very complex language - so the name of the demon was quite manageable for Baran.
* ''Literature/TheDeathGateCycle'', in one of its appendices, describes rune-magic in terms of true names. What a rune-magic spell does is ''change an object's name'', thus causing the object itself to change. The Sartan and Patryn (battling WitchSpecies who use this magic) are each affected by it in different ways:
** Sartan magic emphasizes the ''spoken'' runes; as such, a Sartan's true name in their own language can be used to control them. Most Sartan go by pseudonyms as a result, and when [[KnightTemplar Samah]] introduces himself to a stranger by his true name, this is a sign of both his power and arrogance (since it shows he doesn't fear magical attack).
** Patryns emphasize the ''written'' runes, which they tattoo on their bodies. A Patryn's true name is therefore not the spoken form but the "heart-rune" inscribed in the center of their chest. Messing with this rune can seriously screw up a Patryn's ability to work magic [[spoiler: as Haplo found out the hard way]].
* A major part of the mythology of ''Literature/SkulduggeryPleasant'', and the reason why the magically inclined go by self-referential nicknames. In the ''Literature/SkulduggeryPleasant'' books, everyone has a True Name (theoretically; the only known listing of them was destroyed) and a Given Name (your full given name, e.g. on a birth certificate), and may also take a Taken Name.
** Your Given Name can give someone else power over your actions... to an extent, sorta like hypnotic suggestion. Taking a new name seals your given name, preventing its misuse. However, if someone else learns your True Name, they gain absolute command over you. However, if you learn your own true name (But not as a result of a command), you gain a direct link to magic itself and turn into a PhysicalGod. It's generally advised to then use a magical ritual to seal your True Name to prevent others manipulating you.
* The Franchise/StarWarsExpandedUniverse novel ''Literature/NewJediOrder: Traitor'' has an interesting bit of philosophy that seems to be the inversion of this trope: its proponent states that in naming a thing, you limit it, and in doing so you are saying a half-truth, or worse, a lie.
** At least superficially, this view of words somewhat matches up with a few religions and philosophies, like Zen. If the universe is One whole, then the mere act of trying to describe the Oneness, or one's experience of it, divides and diminishes it into misleading categories.
** There is also the Firrerreo race introduced in the novel ''The Crystal Star'', who have a superstition about speaking someone's name out loud in order to have authority over them. As a result, they never tell others their real name unless necessary, revealing another Firrerreo's name is considered a sign of grave disrespect, and one of the highest displays of respect is to ''not'' use the name of a Firrerreo even though you know it.
* In the (A)D&D novel ''Pool of Darkness'', a demon, due to a curse or another, had to speak his true name ''backwards'', as a VerbalTic. He used his backwards name as an alias in human form.
** In fact, that had a ''second'' fiend (a succubus) whose human form also went by an anagram of her real name, and who was forced back into her natural shape when called by the latter (though it didn't seem to otherwise interfere with her power).
* In Creator/JohnCWright's ''[[Literature/ChroniclesOfChaos The Titans of Chaos]]'', a god casts a spell on the title characters [[IHaveManyNames who have three sets of names apiece]]; he fails because one of them hid one set from him. Granted, someone named Quentin ''Nemo'' should have been a clue.
* ''Literature/TheNameOfTheWind'' focuses heavily on this. Actually learning the names of things, though, is regarded as really, really difficult, and unless a person actually understands the name, he will only hear the common name for the object. Kvothe badly wants to study naming, but is refused by the [[BunnyEarsLawyer somewhat-loopy but brilliant]] Master Namer.
** At one point, Kvothe calls the Name of the Wind in mindless fury against Ambrose Jakis.
** Tamborlin the Great was known to have the Name of most or all things, and his exploits were correspondingly astounding.
** In the sequel, much more of Naming is revealed. One of the Masters of the Arcanum calmly sticks his hand in fire and plays with the coals after speaking the Name of Fire. Many things have names, as evidenced in the variety of first Names that Elodin's class had found.
** As with much of magic in the series, it's one a scale of AwesomeButImpractical - mundane solutions are almost always best when possible, but Sympathy and Alchemy can do some things that can't be done a mundane way, and Naming can do some things even those arts can't.
** Duels between Namers are terrifying things. A Namer with two or three names can tear up the surrounding area for miles with impunity.
** In the very distant past, not only were there people know knew the Names of things, but those who ''created'' new Names. It was a time when humanity had godlike powers and ''created new realms''.
* ''Make Way For Dragons'' concerns the proper name for things. Renaming means reshaping. It's a very tricky situation, as reversing is impossible.
* In the ''Literature/EvieScelan'' series, Evie is surprisingly casual about using her true name for someone who knows that magic exists and names can be used in it.
* This was sometimes the case in ''ForgottenRealms''. Ariel Manx in the Avatar Trilogy, for example, usually uses the pseudonym Midnight as a protective measure.
* The Yn shamans from Creator/JanetKagan's ''Hellspark'' use name magic. The protagonist uses this to talk one down from a rage, pointing out that she doesn't actually know the true name of the person she's angry with and her curse is likely to go awry.
* In ''Literature/TheIronDragonsDaughter'', knowing someone's - or even some''thing's'' - true name can give you almost total power over that someone. Main character Jane, being a human not of that realm, doesn't have a "true name".
* Invoked, referenced, and played as straight as a non-fantasy can play it in Creator/VernorVinge proto-{{Cyberpunk}} story, "Literature/TrueNames", in which the dangers of using your real name on the Internet is a major plot point. Criminal hackers (computer wizards) must keep their identities hidden from each other or risk blackmail or worse.
* The reason why it's so hard for the title magicians in ''JonathanStrangeAndMrNorrell'' to find and summon the Raven King is that they have no idea what his real name is.
* In NeilGaiman's ''Literature/AnansiBoys'', Mr. Nancy (Anansi) and his sons apply this trope in a few ways, one of which being the humiliation of a major villain.
* In the MercyThompson books, TheFairFolk can use someone's true name to control them. True names aren't any sort of magical secret knowledge, although older entities seem to prefer using nicknames and aliases for this reason. In ''Hunting Ground'' a fae greets Anna with her full name and the name of her pack in order to subtly threaten her. Later in the same book, a fae addresses one man with the name he was given at birth and his parents' names, and uses that power to issue him an order he can't resist.
* In ''Literature/TheDemonsLexicon'' by Sarah Rees-Brennan, demon-summoning requires knowledge of the demon's true name. [[spoiler:In a subversion, it's eventually revealed that demons, who tend not to use language, don't actually care what name you call them--what matters is that you ''[[ClapYourHandsIfYouBelieve believe]]'' it's the demon's true name.]]
* Creator/SusanCooper's novel ''The Dark Is Rising'' (part of ''Literature/TheDarkIsRising'' series). Merriman Lyon defeats Maggie the witch-girl (an agent of the Dark) through his knowledge of her true name.
* In Creator/CateTiernan's series ''Literature/{{Sweep}}'', everything has a true name, from plants to people. One of the main characters actually finds out her fathers true name and [[spoiler: uses it to put a binding spell on him so the other characters can strip him of his powers.]]
* Low caste Literature/{{Gor}}eans frequently hide their true names from others due to a fear of this trope.
* In ''A Name to Conjure By'', a SummonEverymanHero spell brings the protagonist to another world where his full, exceedingly long name is a powerful spell. A magician tries to learn the name with a spell, but fails because he can't read the English alphabet.
* In ''[[Literature/DoctrineOfLabyrinths Melusine]]'', Mildmay warns Ginevra not to use her real name when they go to meet Vey Coruscant. At one point she says ''his'' name out loud, but at the time she only knew him by an alias.
* In ''The Book of Three'', the first volume of the PrydainChronicles, [[SupportingLeader Prince Gwydion]] is [[TheOnlyOneAllowedToDefeatYou the only one who can defeat]] [[TheDragon the Horned King]] because he's the only one who knows his real name, which is [[spoiler:never revealed]].
* In Simon Green's ''Literature/{{Nightside}}'' series, the second book features the Speaking Gun that can unmake anything ever created by saying its true name backwards. It's touted as the only actual item that can destroy an angel, whether nefarious or holy. (Little difference between them. Nefarious angels will destroy you because they are evil and enjoy it. Holy ones will destroy you because you're either in the way of the Plan, or simply because you're flawed.)
* Literature/QuantumGravity: True Names ''exist'' and ''work'' on all sapient species...while in Alfheim, home to the elves. They work on elves anywhere, but especially in Alfheim. It's the type of power that makes the target do something, though the exact power has yet to be confirmed: It made a target do something he didn't ''want'' to, but was [[ExactWords worded very specifically]] and whether the action went against his nature is unknown.
* In Robin Hobb's ''Literature/RealmOfTheElderlings'' series, no dragon could lie to someone who demanded the truth with her true name or used it properly when asking a question. Nor could a dragon break an agreement if she entered into it under her true name.
* Creator/GeorgeRRMartin's book ''Dying of the Light'' has a line that invokes this, when the viewpoint character's ex-girlfriend, explaining how she disliked the pet name he'd given her, says (approximately), "Give a thing a name and it will somehow come to be. All truth is in naming, and all lies as well, for nothing distorts as a false name can, a false name that changes both the appearance and the reality...."
* ''Literature/{{Paranormalcy}}'s'' Faeries run by this trope, which, when combined with AdultsAreUseless (or Adults-Are-Too-Pigheaded-To-Realize-The-Consequences) leads to some serious trouble. Especially since some of the Faeries are resentful about it and are all to willing to get revenge in any way [[ExactWords they]] [[JackassGenie can]]. A good example is [[StalkerWithACrush Reth]], who does a pretty spectacular job at twisting every command given to him, though he's not particularly nasty... [[spoiler: until later.]]
* Inverted in the Franchise/DoctorWhoExpandedUniverse Literature/EighthDoctorAdventures and FactionParadox novels. During the Second War in Heaven, the Time Lords battle a race of entities referred to as 'the Enemy'. The Enemy ''does'' have a true name, but the Time Lords almost never use it, as by naming the Enemy, they create the risk of the listener misunderstanding the Enemy as a physical alien race fighting the Time Lords in a physical war. The system of time we know ''(a steady progression of entropy, cause and effect, TimeyWimeyBall, etc)'' is an invention of the Time Lords, and the Second War in Heaven is fought to prevent the Enemy from replacing it with whatever system ''they'' would impose on reality. Thus, the War is so surreal and metaphysical by normal standards that naming the Enemy causes non-Time Lords who cannot understand the principles at work to view the Enemy as a hostile invading force ''(false)'', rather than a fundamentally different and opposing system of time. Thus, the Enemy is a process, an unnatural force of nature, a series of events, rather than anything concrete.
* Elizabeth Haydon's ''Literature/SymphonyOfAges'' novels live on this trope. Especially in her first three books of the series, true names are bandied about or kept secret so they can't be abused as plot points practically every five pages.
* In ''Literature/TheLostYearsOfMerlin'' series, by T.A Barron, names are very important, magically; Naming is even one of the Seven Songs of Magic. If someone knows the true name of someone or something, they have control over it (only Merlin knows the true name of [[spoiler: Excalibur]], so he's the only one with total control over it. Merlin also learns his own true name at the end of the last book.
* In the first book of ''Literature/TheKaneChronicles,'' this is how the heroes [[spoiler:manage to enslave Set]].
** They also use this to [[spoiler:revive Ra and save the world, but Set tricks them to return his true name to him along the way, thereby losing their control over him]] in the third book.
** Also in the third book, Sadie has to convince [[spoiler: an barely conscious and dying Carter to give her his secret name, or "ren", so that she can use a healing spell and save his life.]]
* Actually an important point in the ''ChroniclesOfTheEmergedWorld'', where the Orcish-like Fammin serving the Tyrant all have names which are actually magical words used to force them to obey the orders. This is [[MySpeciesDothProtestTooMuch the Wrong Ones']] main source of fear and {{Angst}}.
* In ''Literature/{{Salamander}}'', the name a wizard uses must be their true name (or a shortened form of it), or else their magic fades. A superstition in-story is that naming a child after a dead wizard will give him some of that wizard's power. [[spoiler: The tradition was started by an immortal wizard who wanted to be able to hide without changing his name.]]
* The short story "True Names" by HarryTurtledove is a parody of this trope. It's set AfterTheEnd in "Eastexas", where the remnants of the American people have reverted to ignorant barbarism. A tribal shaman finds a book about taxonomic classification and believes the scientific Greek names given for animals to be their 'true names' that grant the one who knows them power over them.
* In ''Literature/{{Krabat}}''. Fortunately, TheHero doesn't know the real name of the girl who's able to save him. (Another one wasn't that lucky.)
* Stina Leicht uses both this and WordsCanBreakMyBones in "Of Blood and Honey". Using someone's true name gives you power over them; you can call them to you or command them. [[spoiler: However, it has to be their complete true name: Liam's parents survive Henry's trap because Henry doesn't know Liam's full name, and thus Liam can resist long enough to break through the stone circle.]]
* In Teresa Frohock's ''Literature/MiserereAnAutumnTale'', telling your name is dangerous. And you need to force a demon to tell you its name to exorcize it.
* In ''Literature/GriffinsDaughter'', [[BigBad The Nameless One's]] true name had been stricken from the history books to keep someone from invoking this in an attempt to invoke him enslave him or claim his power.
* ''[[Literature/TheQuantumThief Fractal Prince]]'' features a scifi variation of this trope in the City of Sirr, where True Names are a part of an elaborate control system that allows baseline humans limited use of certain posthuman technologies that should be too complicated for them to operate, while simultaneously keeping them inaccessible to the posthuman Sobornost who would forcefully assimilate the city if it was unprotected.
* ''Cold Cereal'' by Adam Rex turns this into a BrickJoke. The main character is established with the name [[Theatre/MacBeth Scottish Play]]. He got his name when his father, a struggling actor, got a break that changed his life and promised he'd name his firstborn son after the role. At the end of the book, when Queen Titania uses all the heroes' names to incapacitate them, Scottish Play manages to break free of her spell because that wasn't his true name and [[TheScottishTrope that it's not supposed to be spoken out loud]].
* In Creator/PatriciaCWrede's ''Snow White and Rose Red'', a character casts a LoveSpell on one of the heroes. The spell requires his name, however, and she's unaware that he doesn't go by the name he was baptized under. Consequently it has no effect on him whatsoever.
* All of the [[WitchSpecies Insequent]] from the ''Last Literature/ChroniclesOfThomasCovenant'' can be compelled by their true names, and as such they usually go by imposing sounding titles (the Theomach, the Vizard, the Mahdoubt, the Harrow, the Ardent, the Auriference, etc.). It's implied that any Insequent knows (or can readily discover) any other Insequent's true name, but they go to great pains to conceal them from outsiders. Only two are revealed in the novels- ''Kenaustin Ardenol'' (the Theomach) and ''Quern Ehstrel'' (the Mahdoubt). The Ardent manages to make the Harrow back off in one scene merely by threatening to reveal his true name to the gathered companions.
* In ''Literature/{{Orion}}'' by Ben Bova, the title character attempts to introduce himself to a stone-age tribe. Due to belief in this trope, things go very badly.
* In the short story ''[[http://www.tor.com/stories/2013/09/equoid Equoid]]'', of ''Literature/TheLaundrySeries'', the narrator comments on how "Bob Howard" is just a pseudonym he's calling himself in the reports; because he would never do something as daft as write his true name on paper and "give extradimensional identity thieves the keys to our souls."
* Everybody has true names in ''Literature/{{Messenger}}'', and they're given by the psychic Leader. This is a benevolent version as the true names help people discover their purpose in Village (eg. the man now called Mentor becomes a schoolteacher), although they do seem to hold some power as seen when Matty is easily able to rein in his puppy after using its true name.


[[folder:Live Action TV]]
* One of the few ways to break Jasmine's [[{{Brainwashed}} control]] in ''Series/{{Angel}}'' is to hear her true name spoken.
** More specifically, hearing her name spoken stripped her of much of her power, and one of the abilities she lost was her ability to brainwash people. She also suffered permanent GlamourFailure.
* ''Series/DoctorWho'':
** The Carrionites, who are implied to be the inspiration for the witches in ''Theatre/{{Macbeth}}'' and possibly this whole true-name thing. Unfortunately, with them, ItOnlyWorksOnce. Apparently it also works in reverse, as the Carrionites try to overcome the Doctor by this means, but are unable to discover his true name.
** Inverted in the Series 4 episode "Silence in The Library" when the Doctor finds out that archaeologist River Song knows his real name (not just "The Doctor"). He flat-out says that "there's only one reason" why he would ever tell anyone his name, with their conversations and River's comments to Donna making the ''implication'' (but only the implication!) that River could be [[spoiler: his future wife]]. He also adds that there is only one 'time' when he could tell anyone his name. This, plus River's use of the Tenth Doctor's grim CatchPhrase for people he knows are going to die ("I'm sorry, I'm so sorry") leads to the theory that she will be present at his death.
** [[spoiler: Sometime in the future, there will be a time and place where the Doctor will be asked the first question, the oldest question - "Doctor who?" - and must answer truthfully. The Silence are willing to kill him to stop him ever answering; they believe silence will fall (or must fall) when the question is asked.]]
** In the classic serial "Silver Nemesis", Lady Peinforte claimed to know the Doctor's true name.
** The Doctor's true name is said to have been written in the Medusa Cascade itself, possibly as a result of sealing the Rift there back when he was a mere ''boy'' of 90.
* Paige from ''Series/{{Charmed}}'' has the power to 'orb' objects by focusing on and verbalising them. This proved to hold a prominent weakness in the episode 'Sense and Sense Ability,' where the Crone rendered her unable to speak, and, hence, use her power.
* On ''Series/SoWeird'' Bricriu could only be banished if you know his name. When he possesses Fi's brother, he challenges her to figure out his name, at three guesses, giving her almost no hints. Near the end of that episode, Fi renegotiates and he lets her have as many guesses as she needs for one hour. She then uses a program to goes through every possible letter combination until it gets his name; [[MagicalComputer how she got her computer to do that is unknown]]. In his (and her) final episode, his name is wiped from her memory when Fi's connection to the spirit world is removed. However, she didn't need it this time: he was in her computer, so she just traps him on a floppy drive.
** Subverted during his second appearance, when he possesses Molly. He manages to trick Fi into letting him stay for 24 hours. Her agreement to this constitutes a MagicallyBindingContract, so even his true name can't be used to banish him during that period.
* In ''Series/StargateSG1'', the team is looking for the Holy Grail. They are warned that part of the quest will involve battling a dragon and that the only way to stop it, is to speak the name of the one who controls it. Daniel theorises that this is based off this trope, but his actual explanation is that the dragon is a machine of some kind and that the name is some kind of code word.
** They are told they will need to speak "the guardian's name." They assume this means they have to guess the name of the dragon; it is not until they are being attacked by it that Daniel figures out "the guardian" is the person who set up the whole quest: Morgan Le Fay (or Ganos Lal, as it was her true, Ancient name that beat the dragon.)
* A [[CutawayGag sketch]] on ''Series/TheYoungOnes'' showed two demons in Hell complaining about their own names being too weird. Apparently they could only be summoned to Earth to collect souls if a mortal said their names, and this unlucky pair were called Orgo and Ftumch. Thanks to a misprint in a newspaper Rick reads aloud Ftumch manifests, and after failing to claim Neil and Vyvyan settles for a guy who had come to award one of the flatmates with a car through a contest.
* In the ''Series/StarTrekVoyager'' episode "Spirit Folk", holograms of superstitious townfolk try to apply this trope and fail.
--> '''Townfolk''': If you can get a spirit to reveal his true name, you'll render yourself impervious to his charms! What is your true name?\\
'''The Doctor''': I haven't decided on one yet.
* In an episode of ''Series/BabylonFive'' where Ivanova was using an alien supermachine to telepathically search for the [[SufficientlyAdvancedAlien First Ones]], she accidentally astrally ran into the Shadows. She tried to escape, but had trouble breaking contact:
-->'''Ivanova:''' I can't. It... it knows I'm here. It knows my name!
* In a sketch on ''Alexei Sayle's Stuff'' involving a Masonic Lodge style religious cult [[MundaneMadeAwesome based around pencils]], mention is made of "The Great Architect of the universe, whose name we cannot say... for it was written in pencil and got a bit smudged."
* In an episode of ''Series/NCISLosAngeles'', the episode's villain, an information broker, manages to coerce Callen (whose first name is unknown by all, including him, with the exception of the fact that it starts with G) to obey his instructions by saying "I know what the 'G' stands for". The instructions nearly get Callen killed because the broker ordered him to stand in for the broker in dealing with some troublesome clients. Later, when Callen and the team find the broker's hideout, Callen gets the chance to learn for himself what the G stands for when he finds a file labelled "Callen, G" but is forced to abandon the file when the broker's security measures trigger [[OutrunTheFireball explosives/incendiary devices that destroy all the files and equipment in the base.]]
* In the eighth season of ''Series/TwentyFour'', Dana Walsh receives a call from her ex-boyfriend revealing that he knows that her true name is Jenny Scott, and forces her to work with him under threat of revealing it. Since she's a convicted felon [[spoiler:and TheMole inside CTU]], she does as he says in order to keep him quiet.
* In ''Series/{{Merlin}}'', many Druids and Creatures of the Old Religion refer to Merlin by his true name of "Emrys".
--> '''Merlin''': Why does he call me ''Emrys''?\\
'''Dragon''': Because ''that'' is your name?
* In the first episode of ''Series/OnceUponATime'' Snow White and Prince Charming are warned against revealing their names to the imprisoned BigBad Rumplestiltskin.
--> '''Guard:''' If he knows your name he'll have power over you.\\
'''Rumplestiltskin''': ''Snow White and Prince Charming.'' You insult me. Step into the light and take off those ridiculous robes.
* In ''Series/MythQuest'', Matt tells his daughter Cleo that since she took the place of Isis, she has all the powers of Isis, which came from Isis' discovery of Ra's true name.
* In the ''Literature/TalesOfKolmar'' trilogy, knowing someone's true name gives power over them - they can be controlled when their true name is used. The Kantri (dragons), for example, have long names like Khordeshkhistriakhor, but they use a diminutive of their true name for everyday use (for example, that dragon is known as Akhor), and share the true one only with their lover and possibly best friends.
* In ''Series/{{Supernatural}}'', knowing a supernatural being's name or mark allows you to forcefully summon them to your location.

* Nightwish's "Nemo" [[WordSaladLyrics may or may not use this]].

[[folder:Mythology and Religion]]
* OlderThanDirt: [[EgyptianMythology Ancient Egyptians]] actually believed in the spiritual power of names, especially of one's own soul and those of the gods; for example, Isis (Au-set/Aset) once tricked the high god Ra into giving her a great deal of power by creating a serpent whose venom only she could counteract and having this viper bite him. He suffered but as a god was unable to die. She wrangled his True Name from him in exchange for the antidote which ended his suffering.
** There was also the belief that if you destroy all records of someone's name, their '[[OurSoulsAreDifferent Ka]]' would no longer exist. This has been attempted on unpopular pharaohs (like Akhenaten by everyone, and Hatshepsut by her successor and stepson).
** Likewise, in the Egyptian ''Book of the Dead'', the names of a number of guardians of gates in the netherworld are listed; by knowing them, the deceased gains power over them and will be able to pass through those gates.
** Furthermore, the [[AnthropomorphicPersonification goddess/incarnation]] of justice, Ma'at, has a true name that is not written anywhere because of the danger that someone might decide to speak it backwards.
* In the original writings of Literature/TheBible, God's name is written around 7,000 times; the four letters that make it up are called the Tetragrammaton. Later on the Jews became superstitious regarding the name and would not say it, and since the original written form of the Hebrew language only consisted of consonants, the original pronunciation was lost. Another theory is that, according to Wikipedia, four letters of the Hebrew alphabet can double as vowels, ie ''[[http://en.wikipedia.org/wiki/Mater_lectionis mater lectionis]]'', including Yodh "Y, I, J, or a vowel"; He "H, silent, or a vowel"; and Waw "W, V, or a vowel"; which all make up the Tetragrammaton. That is why in [[UsefulNotes/{{Gnosticism}} Gnostic]] literature, one of the names of the demiurge is Iao, Jao, Yao, or any other derivative form you can get from using the mater lectionis method. Either way, the loss of the correct pronunciation of the name of God in the present can make others to mistakenly believe that the name of God was used in this manner by those who did know it, [[AvertedTrope while actually]] the name was well known and often used during BibleTimes. [[DefiedTrope It was a crime for the Jews to practice magic.]]
** And one of the privileges God granted to Adam was to name all the animals in creation.
** The Jewish legend that changing the name of a gravely ill person can hide him from the Angel of Death. Similarly, it is against custom to name a baby after a currently living relative, since, should the Angel of Death seek out the older family member, the younger might be taken by mistake.
** Shemyaza, one of the Grigori/Watchers (the angels who were enamoured by human women and came down to earth to take them as their wives) was seduced by Istahar into revealing God's true name. [[WhatHaveIDone He regretted it later]], and threw himself into the constellation Orion.
* In Homer's ''Literature/TheOdyssey'', Polyphemus the Cyclops is tricked by Odysseus/Ulysses. Odysseus claims his name is "no man," causing the Cyclops to be thought insane or cursed when he says that "no man" blinded him. However, Odysseus seals his fate after escaping when hubris prompts him to announce his True Name, allowing Poseidon, the Cyclops' father, to take revenge by sending a storm to destroy Odysseus' ships.
* In NorseMythology, specifically some re-tellings of the story of Sigurd, telling a dying person (and particularly a dying Dragon) is a bad idea, because if a dying person (or Dragon) curses you by name, that curse is guaranteed to be carried out.
* Traditional Shinto beliefs include a form of magic called ''kotodama'', in which you can compel your target to do almost anything if you know their true name. Series that feature this include ''WagayaNoOinariSama'', ''{{Tactics}}'', and ''Her Majesty's Dog''.
* Finnish mythology has a variation of this trope: knowing something's ''birth'' gives you power to reverse it, and gain control over it. There are hundreds of fractures of "birth-words" for various things, gathered from oral tradition. For example, knowing the Birth of Iron should allow one to treat wounds caused by an iron weapon.
* The City of Rome's true name was an actual state secret kept as jealously as the US missile launch codes which is understandable [[ItMakesSenseInContext given their beliefs]]. It was illegal to speak it out loud lest priests from a enemy state use it to curse Rome.

[[folder: Other Sites ]]
* ''Wiki/SCPFoundation'', [[http://www.scp-wiki.net/scp-992 SCP-992 ("Gaia's Emissary")]]. SCP-992 has the mystical ability to know the true names of things, including living things such as human beings (both living and dead) and plants. He is able to create non-living things he has named, including unusual weather and the Aurora Australis.

[[folder: Tabletop Games ]]
* In ''TabletopGame/MageTheAwakening'', knowing a person's real name makes using magic on them from a distance much, ''much'' easier. As a result, mages take "shadow names", sharing their true names only with their closest allies (as sometimes having someone be able to cast spells on you is beneficial).
** The Awakening itself is supposed to result from a prospective mage metaphorically travelling to a [[EldritchLocation Supernal Realm]] and inscribing their name on its Watchtower.
** The TabletopGame/OldWorldOfDarkness version, ''TabletopGame/MageTheAscension'', had something similar with several of the Traditions - the Order of Hermes mages had a 'True Name', which was an Enochian phrase that described them. They concealed it in a Shadow Name, and many higher-powered mages found ways of inserting traps into the shadow name that would harm enemies trying to determine their True Name. Knowing a Hermetic's true name had a similar effect as in the new game. The technomantic Virtual Adepts had something similar with their Internet handles - but someone who goes by the name pronounced 'Coyote' could well be C0y0t3, (oy0t3, or any other [[LeetLingo 1337]] variant.. good luck figuring out which would be their True Name...
* ''TabletopGame/MummyTheResurrection'' uses an Egyptian-influenced truename magic system called "Nomenclature." One of the system's ultimate powers is the ability to erase someone or something's name, removing them from existence (by making the universe forget they exist).
** On the TabletopGame/OldWorldOfDarkness note, the Art of Naming from ''TabletopGame/ChangelingTheDreaming'' no doubt caused many a Storyteller endless distress. The ability to rewrite someone's true name (essentially, the core of their being) ''does'' come with the risk of the Fates noticing you...
** Continuing on with the [=oWoD=] name craze, ''TabletopGame/DemonTheFallen'' gives characters three names. A Fallen has whatever name or alias they are using in the real world. They also have a Celestial Name, which gives them remote communication and viewing with anyone who knows it. And finally they have True Names, which can be used to summon, bind, and exorcise them. Guarding one's names against hostile parties could be a very important part of the game.
** And then there were the Tremere in ''TabletopGame/VampireTheMasquerade'', whose projects included studying the Human Genome Project and the human genealogical records of the Church of Latter Day Saints in conjunction with one another in order to discern ''the true name of the human species''.
* ''TabletopGame/DungeonsAndDragons''
** 1st edition.
*** Several spells usable against creatures from other planes (Banishment, Binding, Planar Call and Torment) required the use of the creature's true name.
*** In their original appearance in module S4 ''The Lost Caverns of Tsojcanth'', certain other planar spells required knowledge of the target's "personal name" (another term for True Name): Abjure, Dismissal, Dolor.
*** The Call and Truename spells were usable against any living creature with a true name, not just otherplanar creatures.
*** The Prison of Zagyg magic item required knowing the target's true name in order to capture it.
*** The Oriental Adventures supplement said that in Oriental lands a person's secret name is given to them at birth and never revealed to others. Learning a person's secret name gives you magical power over them.
*** OD&D Supplement IV ''Gods, Demi-Gods & Heroes'' and the 1E ''Deities and Demigods Cyclopedia''. In the Celtic mythology every creature had a secret name linked to its soul. Anyone who knew the name could control the creature or simply make them die. The deity Oghma automatically knew the secret name of any non-godlike creature.
*** ''Magazine/{{Dragon}}'' magazine #15 article "Dragon Magic". All dragons have a secret name that they keep carefully hidden. If a dragon's true name is spoken, anything brought about by the dragon's magic is dispelled and the speaker can demand one (and only one) service from the dragon.
*** ''Magazine/{{Dragon}}'' magazine #50 article "True Dragons". When a dragon's True Name is spoken, there's a 5% chance the dragon will hear it, no matter how far away, and know the distance from and direction toward the speaker. A dragon is immune to Charm and Hold spells and magical control devices unless the caster speaks its True Name. If someone drinks a Potion of Dragon Control and knows a dragon's True Name, the dragon gets no saving throw vs. the potion. If someone speaks a dragon's True Name to it and makes a request the dragon must grant it.
*** Mezzodaemons and nycadaemons had personal names which they kept very secret. If an archdevil, demon lord or other powerful infernal creature discovered their name, it could be used to control the daemon.
*** Both demons and devils had a SpeakOfTheDevil variant. If the name of a demon lord was spoken aloud there was a 5% chance it would turn its attention to the speaker. Each devil had a talisman with its name on it, and speaking the name on the talisman would call forth that devil to appear before the speaker. In both cases, unless the demon or devil were controlled, it would attempt to kill the speaker.
** 2nd edition AD&D said that knowing a lich's true name conferred power over it.
** 3rd Edition:
*** The supplement ''Creature Collection''. In order to destroy an Unhallowed, its True Name must be learned and spoken aloud to attract the attention of the gods before attacking it.
*** The supplement ''Book of Exalted Deeds'' goes into some detail with the Words of Creation. As a precursor to the Celestial tongue these are considered inherently good (no evil creature can speak them or [[BrownNote bear their sound]]) and include creatures' true names. A true name is unique to a single individual and is expensive and time-consuming to research, but discovering it allows the character to perform various useful tricks on them, anything from a penalty on saves to casting ''teleport'' or ''greater teleport'' on them, [[HolyIsNotSafe at the cost of 5d4 points of nonlethal damage to the speaker]].
** Edition 3.5 had a character class called the "Truenamer," who used this style of magic by learning the language of creation. A truenamer can technically use any utterance (spell) he knows any number of times per day, limited by the fact that the universe hates being screwed with, so spells get progressively harder each time per day they're used. That, and they screwed up the main way to use it so badly that it's nigh impossible to say it more than once.
* Daemons of Chaos in ''TabletopGame/{{Warhammer}}'' and ''TabletopGame/{{Warhammer 40000}}''. The [[DemonSlaying Ordo Maleus]] maintains those which are known in The Grimoire of True Names, which in-game enables those equipped with a Grimoire to cut the Daemon's Weapon Skill (ability to strike blows in close combat) in half. (Hey, it can't kill you if it can't hit you!) Sometimes [[DemonLordsAndArchdevils Greater Daemons and Daemon Princes]] will [[{{Pride}} go so far as to announce their true name]], just to point out how doomed whoever stands against them is.
** Works mechanically in two ''TabletopGame/DarkHeresy'' supplements. Knowledge of a Daemon's True name gives the player bonuses to summoning and commanding that particular daemon. It is also featured in the "Thy Name I Keep" background where a character starts knowing a daemon's true name (or at least a fragment of it).
** In ''TabletopGame/BlackCrusade'', '''player characters''' can receive a Daemonic name from their patron Chaos God. This brings them additional Infamy but should an opponent discover the name they gain an additional Infamy/Fate point (which can be spent to reroll failures, enhance successes or even avoid death) when fighting said player.
* In ''TabletopGame/{{GURPS}} Magic'' the alternate rules suggest that knowing someone's true name (which can be things like DNA or Social Security number) give a very large bonus on targeting them with a spell. It also makes it easier to control summoned creatures.
* The supplement book ''Mythic Egypt'', written for both Rolemaster and the Hero System, naturally discussed true names. For purposes of magic in that setting, many spells meant to affected others required knowledge of their true name first (though there was also a spell to discover that by observing somebody directly which naturally didn't have that prerequisite) or otherwise simply wouldn't work, and one of the supernatural races of the setting had the explicit weakness that all of them shared the ''same'' true name...that had gotten out long ago.
* In ''TabletopGame/LegendOfTheFiveRings'', the "Lying Darkness" had avoided being named at the creation of the world. This left it undefined and without limitations, and it tried to unmake the world. The world's heroes were finally able to stop it by gaining the power to name it, thus fixing its nature and imparting the qualities of the (previously existing, but no longer used) name Akodo.
** Also, name-based magic is practiced by non-rokugani. Within Rokugan, it is practiced by the nezumi (rat people) and an angered nezumi shaman can cause a minor CosmicRetcon to {{Unperson}} you if he snatches your true name away.
** Oni can do something similar. They are nameless in their native realm and can't remain in the mortal world unless someone lends them a name. If the oni ever fully wrests the name from its original owner, the now-nameless victim is forced to obey the oni's commands.
* ''TabletopGame/{{Exalted}}'' features a reversal with She Who Lives In Her Name. Anyone who [[BrownNote hears her true name]] becomes a drone who can only meditate on the inherent harmonic perfection of it.
* Almost all magic in the TabletopGame/{{Earthdawn}} system is based off of Names. The importance of Names in the system is emphasized by the fact that the collective term for all sentient races is "Name-Givers."
* ''TabletopGame/{{Shadowrun}}''. Knowing a free spirit's true name allows it to be more easily summoned, controlled and banished.
* ''Amber Diceless Role-Playing'' game (based on Creator/RogerZelazny's ''Literature/TheChroniclesOfAmber'' stories).
** Using the target's true name is necessary or helpful when using certain Power Words. Including the target's true name makes the Power Word "ASKIIR!" (Psychic Disrupt) much more effective on it.
** It is necessary to use a target's true name when using the Power Words "KROLAK!" (Neural Disrupt) or "SCHANG!" (Resume True Form) against it. If the target does not have a name, the user must have a higher Psyche score to use those Power Words against it.
* ''Hot Chicks'' RPG. When casting the Bind Spirit spell, using the spirit's True Name reduces the spirit's chance to resist the spell, as well as making the caster the spirit's hated enemy.
* ''Witch Hunter: The Invisible World''.
** Knowing a creature's True Name allows the casting of or enhances the effect of the following spells: Spirit Son, Bond of Blood, Spirit Brother, Spirit Father, Magician's Mark, Sigil of Warding, Mark of the Minion, Mark of Dominion, Summoning of the Unseen, Exorcism, Exchange of Hurts, Strip Power, Compel Truth, Breath of Crom Slough, Compel Spirit, Eye of the Avenger, Circle of Summoning, The Unseen Hand, Séance, Trap Ghost, Raise the Dead, Charm and Scry.
** Creatures can have the Mystical Price called True Name. If another being uses the creature's True Name while conversing with it, the speaker gains a bonus on the use of personality-based skills against the creature. It is also more difficult for the creature to attack someone who has spoken its True Name.
* The Ven (the dominant species) in ''TabletopGame/HousesOfTheBlooded'' all have three names: 1. A public name known by all with no power. 2. A private name with limited power (required for certain spells) given to allies, and 3. A true private name, known to the Ven and their mother (who gives them that name) which removes almost all spell resistances given only to the most trusted of allies and usually only needed for Unbreakable Vows.
* ''TabletopGame/{{Ironclaw}}''
** One of the published adventures in the first edition had a character who was Invulnerable to attacks by anyone whose name he knew. Naturally his social skills are based on tricking people into revealing their names.
* In the second edition, characters can take the Gift "Anonymous", where they forsake their name (meaning they can't call themselves by any name, though other characters are allowed to come up with and use nicknames for them) in exchange for a boost to their magic resistance.
* Judges Guild adventure ''Tegel Manor'' (revised & expanded, 1989). The Banshee of the Rump family can kill someone just by speaking their True Name.
* ''[=Mythus=]/Dangerous Journeys''
** Knowing the Truename of a spirit creature (demon, elemental, ghost etc.) made it easier to summon that creature.
** A vampire had the power to gain limited control over a creature if it knew the creature's Truename.
* ''LejendaryAdventures''. The magical item Morben's Supernatural Shackles would only work on an intelligent target if the target's secret (true) name were spoken.
* A ''TabletopGame/MagicTheGathering'' card for every trope: [[http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=376562 True-Name Nemesis]] plays off this idea, in that once he knows your true name, he is immune to your power.
* ''TabletopGame/HeroSystem'' supplement ''Fantasy Hero Companion''. All six types of demon (Demon Lord, Fire Demon, Amorphous Horror, Deceiver, Hordling and Hell Hound) had to obey anyone who knew their true name.

[[folder: Video Games ]]
* An interesting twist on the theme occurs in ''VideoGame/PlanescapeTorment'', in which the main character is the Nameless One. His utter lack of a name prevents mages, demons, {{Big Bad}}s, and anyone else from scrying upon him, and makes it next to impossible to find any history related to him. [[spoiler:Later discovering his original true name grants him what is possibly the largest single-shot experience gain in any RPG, ever. (2 million XP in case you're wondering.)]]
** [[spoiler: It also lets him get the best ending by itself.]]
** The trope is twisted even more if the Nameless One attempts to ''take'' a name. Calling himself "Adahn" to [=NPCs=] results in an unusual focus of [[ClapYourHandsIfYouBelieve belief]] in the world; he's certainly not Adahn, but people start to believe that there is an Adahn wandering around that looks and acts just like you. Do it enough times, and eventually enough people assume that Adahn exists that... well, you can meet him yourself in a bar, proving that words cannot only break your bones, they can make them, too!
** This is all based on the game universe, as defined by the ''TabletopGame/DungeonsAndDragons'' sourcebooks. Sigil is a city where, if enough people believe it, it exists/occurs/whatever. A strong enough will can change the world. In fact, one of the main character's memories is of an argument he entered into with an unknown man. By applying apparently credible logic (it's never shown), he proves that the man doesn't exist. The man then reveals that if he were to believe it, he'd... and then he disappears from existence. [[spoiler:One of the endings of the game involves the ''main character'' willing himself out of existence in a similar fashion.]]
* In ''VideoGame/{{Achaea}}'', the Occultist class has the ability to take a "true name" from a player's corpse. They can later use the true name in a very strong attack against that player.
* The "No one ever seems to realize this" bit is pointedly averted in the MUCK game [[http://scross.homeip.net/Wiki/index.php/Main_Page SouthernCross]], as those taking the flaw 'Bound by Superstition', among other significant quirks, have a True Name. This is so common in the setting's fae cultures, that a deep-set tradition is to either name an afflicted child with a difficult and esoteric name, then give them a new name by which they're addressed normally, or for the afflicted character (if they have one) to see to it that people always call them by the name of their domain (the concept or element many fae-blooded characters embody). 'Course, it's also played straight in that another part of said culture is the intrinsic value placed in knowledge of one's true name, and so just forgetting what your True Name is and having done with it is rather frowned upon.
* ''Franchise/TheElderScrolls'' universe states that all Daedra have both a neonymic and a protonymic. The neonymic is their true name that they can change. It holds a certain amount of power, but is hard to use against them because they can change it at any time. However, the protonymic is their true name that they cannot change. It is heavily implied that through use of the protonymic mortals can do horrible things to even the most powerful of Daedric princes. The player character in Battlespire managed to banish Mehrunes Dagon through [[http://imperial-library.info/content/facing-mehrunes-dagon#Mehrunes_Dagon using them both]].
** Played with in ''VideoGame/TheElderScrollsVSkyrim'', where shouting a Dragon's name in Thu'um (dragon language) is viewed as a challenge to that dragon; it will usually seek out whoever made the shout out of curiosity and honor, but is under no compulsion to do so.
** This is also true for Dragonborn, as the Greybeards summon them to High Hrothgar by calling out ''[[NotSoDifferent their]]'' true name via the Thu'um.
* In the Nintendo 64 Game, ''VideoGame/AidynChronicles: The First Mage'', [[spoiler: A massive portion of the quest is for the main character to learn his true name and thus gain the power to defeat the Big Bad]]
* In ''VideoGame/{{Warcraft}}'' universe, knowing a demon's true name gives you some power over it. This is presumably how warlocks control their demon minions, as enslaving a random demon will only allow them to control it for a few minutes and the two warlock minions without an individual name (Doomguard and Infernal) will only stay summoned for a limited time (they used to break free and attack the player, but now they just despawn). One level 60 ''VideoGame/WorldOfWarcraft'' quest chain, which was removed in the Cataclysm expansion, culminated in a quest called "You are Rakh'lih, demon", where the demon's True Name was etched into a specially-forged weapon that the player had to create.
* ''[[VideoGame/CityOfHeroes City of Villains]]'':
** The game brings us the voodoo-themed Mr. Bocor. At the behest of a contact, the PlayerCharacter can attempt to blackmail Mr. Bocor into working with them by threatening to publish his true name. In classic [[TheTrickster trickster]] form, though, Mr. Bocor implies HelloInsertNameHere has the ''wrong'' true name.
--->''Now, what has she sent in this envelope? Ah, of course. How droll. The child has uncovered what she thinks is my true name, and now believes she can blackmail me into telling you what I know.''\\
''Well, maybe I'll tell you, but not because of her.''
** Knowing the true name of the Envoy of Shadows is the only way to get rid of him as he just keeps coming back every time he is killed.
* In ''VideoGame/{{Touhou}}'', the shopkeeper of Kourindou, [[TheOneGuy Rinnosuke]], has the power to determine the True Name and purpose of objects, [[RequiredSecondaryPowers but not how to use them]].
** In Chapter 14 of ''[[http://en.touhouwiki.net/wiki/Curiosities_of_Lotus_Asia Curiosities of Lotus Asia]]'', the canon material in which he is encountered, Reimu brings Rinnosuke a bone that is so old the ancient creature it belonged to ''has no True Name''.
* Your [[spoiler:former]] co-workers in ''VideoGame/DeusEx'' are two difficult cookies to crack if you end up fighting them straight. However, some snooping, hacking, and risky bets will net you their respective killswitches. The results of speaking their "True Names" are... [[LudicrousGibs impressive]].
* In the SNES ''TabletopGame/{{Shadowrun}}'' game, a jester spirit challenges you to learn his true name; if you succeed, he tells you how to find the BigBad, and will assist you during the fight. [[spoiler:It's not Nirwanda, it's Laughlyn, and only by threatening the vampire who tells you this with a stake can you get him to tell you the truth.]]
* In ''VideoGame/DragonAgeOrigins'', [[spoiler:Connor]] mentions that the Desire demon he unwittingly summoned [[spoiler:in a bid to save his poisoned father]] refuses to tell him its name, since "names hold power".
* In ''VideoGame/StarControl 3'', you can find an object that contains the true name of the Eternal Ones, a mysterious evil race. If you let the robotic Daktaklakpak learn this true name, they will first essentially orgasm and then self-destruct.
* In ''VideoGame/BreathOfFireIV'' this is used in a ''particularly'' brutal fashion by General Yohm to track down KingInTheMountain (and eventual WoobieDestroyerOfWorlds) Fou-lu. Fou-lu is a [[PhysicalGod half of a draconic deity]] that was SplitAtBirth, but was still so powerful that he became GodEmperor of the VestigialEmpire that summoned him; unfortunately for him, this causes a bit of CursedWithAwesome as ''the mere act of speaking Fou-lu's name creates such ripples in the universe that anyone who is psychically active can use these to track them down like a bloodhound following a scent''. Oh, and Yohm is not only sensitive to these vibrations but is also TheDragon to TheEmperor who sees the reawakening of the KingInTheMountain as an UnwantedRevival and wants Fou-lu ''dead''. ''[[RoaringRampageOfRevenge Hilarity does not ensue]]''.
** This even results (at one point in the game) with Fou-lu essentially pulling SpeakOfTheDevil on ''himself''. Unfortunately, at one point he decides (in a fit of despondency) to tell [[CountryMouse Mami]] his life story in the form of a historical legend...which involves the use of his name. Things go ''rapidly'' to hell from there.
* Invoked in ''VideoGame/MetalGearAcid'' - Hans Davis [[spoiler: is not the real name of Solid Snake.]] However, [[spoiler: Snake was manipulated into believing that this is]] his true name in order to be put under Neoteny's control.
* In ''VideoGame/TalesOfSymphoniaDawnOfTheNewWorld'', if [[spoiler: Ratatosk were to learn the new Mana tree's real name, he could take it from Martel and control it. Even without the threat of Ratatosk, the tree is so young that no one outside of the cast of the original game can know it yet.]]
** Also brought up to a smaller degree in the [[VideoGame/TalesOfSymphonia original game]]. Sheena says that everyone in Mizuho hides their real name and uses another name and no one besides their family and the chief know it. Although it's just a tradition and nothing magical or significant beyond that.
* Hanar (jellyfish people) from ''Franchise/MassEffect'' have "Face names" and "Soul names". They usually refer to themselves as "This One," however. This is just a matter of courtesy, and when asked about it they mention it is rude to use one's soul name with someone they don't know very well. At no point is it suggested that knowledge of the soul name is connected (or is believed to be connected) to some sort of power or control.
* In ''[[VideoGame/SamAndMaxFreelancePolice Sam And Max]]: What's New, Beelzebub?'', Sam can thwart an illusion created by Peepers by saying his true name. Unfortunately, Sam does not know his true name, and all parts of it wind up being censored by the censorship branch of Hell (turns out it's [[spoiler:[[UnfortunateNames Dick Peacock]]]].) He can also reveal Girl Stinky's true form by stating her true name... which [[FridgeLogic stops making any iota of sense]] when the third season completely retcons Girl Stinky's origins.
* Parodied in the new [[Videogame/ShadowWarrior2013 Shadow Warrior]] game, where Lo Wang demands to know his demon companion's name because he read about this trope somewhere. When Hoji gives his name, he reacts in shock that Lo Wang could pronounce it and states that he must be one the prophecies spoke of: A gullible idiot who believes everything he hears.
* The combat-system of ''{{Tsukumogami}}'' is built around the use of true names. The titular evil spirits are usually immaterial and thus impossible to fight, but by correctly identifying the everyday object they are possessing (figured out through various hints), you can force them to take on a solid form, and either [[{{Mon}} capture]] or destroy them. (Incidentally, this effectively serves as a subversion of one of the rules stated at the very beginning of this page - their True Names effectively ARE objects.)
* In ''VideoGame/MetalGearAcid'', the reason Alice saddles Solid Snake with a JekyllAndHyde evil personality that he occasionally switches into is because her MindControl PsychicPowers only work on those who have a true name, and Snake (in this continuity) is [[NoNameGiven completely nameless]], other than his {{codename}}. She used a combination of {{Gaslighting}} and drugging to render him suggestible enough to plant a secondary personality - which ''did'' have a true name - in his mind, and then attempted to engineer a SplitPersonalityTakeover, after which he would be helpless and she would be able to control him completely. If she hadn't been forced to unveil her plan to Snake and then got herself HoistByHerOwnPetard, she was on track to pulling it off.
* Chapter 4 of ''VideoGame/PaperMarioTheThousandYearDoor'' features a specter that specializes in [[DittoFighter copying]] and ''[[GrandTheftMe stealing]]'' his opponents' bodies. The copying presents no issues, but when he steals Mario's body, the two of them are unable to do any harm to each other until Mario learns and speaks his real name, [[spoiler:Doopliss]], to weaken the spell.

[[folder: Web Animation ]]
* In one WebAnimation/StrongBadEmail episode, Strong Bad reveals that getting Bubs to say his name backwards minus the first 'b' (Sbu) will force him to give you a free lunch special. [[spoiler:When he does, however, it's revealed that doing that just makes him lose his superpower- being able to fly. He never used it often because he can only hover a few inches off the ground since he gained weight.]]

[[folder: Web Comics]]
* "True Names" are a heavy theme in ''Webcomic/{{Shadowgirls}}''. First, Becka gains the respect of a sea monster by telling it her name. After that monster tells her there is power in names, Becka is then able to summon her full power by saying the real name of the Shadowchild within her.
* Played with in ''Webcomic/{{Goblins}}''. According to a house rule, the pit fiend can be forced to serve any mortal who speaks his true name. Incidentally, his true name is definitely not Richard, Francis, Leslie, Winkypoop the Slippery Monkey, or Walter. [[spoiler:It's Grinnorarcen.]]
* No doubt will be a huge theme in ''Webcomic/{{Namesake}}'' especially since one of the characters has "sold their name."
* Webcomic/ElfBlood's sympathetic magic works best with these. The knowledge of a true name drove the entire Sister, Sister arc.
* In ''Webcomic/{{Sinfest}}'', [[http://www.sinfest.net/view.php?date=2011-11-24 Satan sneers at Criminy's claim to the book because he doesn't even known its true name.]]
* In ''Webcomic/{{morphE}}'' a mage can have a link to a person by knowing their true names. Amical convinces his seedlings to take on code names and uses his knowledge of their true names as leverage to get them on his side. Even the audience only knows 2 of the 5 seedling's true names.
* In ''Webcomic/SluggyFreelance'', the demon Kozoaku gains power whenever somebody says his true name properly. Gwen points out that in that case, maybe people shouldn't be ''shouting it from every street corner''. [[spoiler: So the gods magically changed his true name to TheUnpronounceable K'Z'K.]]

[[folder: Western Animation ]]
* ''WesternAnimation/AmericanDad'' had Steve playing an MMORPG where his character dies when someone says his name backwards. His sister Hayley uses this little-known fact to humiliate him in front of his friends, who instantly go from praising him to constantly belittling him. When this happens, Hayley's boyfriend convinces her to go with him on a long quest for an item to revive Steve. After he comes back, he goes to take revenge on his friends for maltreating him, only for them to just say his name backwards the second they see him.
* ''WesternAnimation/FamilyGuy'' employed a similar gag when, in a cutaway scene, Adam West writes down ''Jeopardy!'' game show host Alex Trebek's name backwards, thus banishing Trebek "back to the fifth dimension where he belongs."
* ''WesternAnimation/DoraTheExplorer'': "Swiper no swiping!"
* In ''WesternAnimation/{{Minoriteam}}'', Fasto had to stop a Galactus knock-off from eating the world. So, he threatened him with his real name. The real name was so embarrassing that it worked.
* In ''WesternAnimation/Ben10UltimateAlien'', Charmcaster explains that in the MagicalLand of Ledgerdomain, to know someone or something's true name is to have power over it. The villain Adwaita has the Alpha Rune, the true name of ''magic itself'', making him an unstoppable PhysicalGod[=/=]RealityWarper, at least within Ledgerdomain. At one point, Kevin taunts Charmcaster about how she told him her name was Caroline, but she retorts that "Caroline" is just an alias. [[spoiler:Later Charmcaster obtains the Alpha Rune, making ''her'' nigh-omnipotent within Ledgerdomain.]]
** For the record, Charmcaster's real name is [[spoiler: "Hope".]]
* In ''WesternAnimation/AdventureTime'', only Finn, Jake, and Marceline know that [[spoiler:the Ice King's real name is Simon. [[IdentityAmnesia Not even the Ice King himself knows]]]].
* Inverted in ''WesternAnimation/DannyPhantom'' with Ember, the ghost of a rock star who becomes more powerful for each person cheering her name.

[[folder: Real Life ]]
* Used in bizarre fashion in the [[UsefulNotes/BritishPoliticalSystem House of Commons]], where members are only referred to by one of a variety of titles. Only the Speaker uses the name (always the Full Name) of the members, and explicitly "naming" someone is either an insult, a reprimand, an enormous faux pas, or is calling for them to speak - depending entirely on context.
** In the United States Senate only the presiding officer may be directly addressed in speeches; other Members must be referred to in the third person. In most cases, senators do not refer to each other by name, but by state, using forms such as "the senior senator from Virginia" or "the junior senator from California." [[http://www.youtube.com/watch?v=yxLV0bVysnk The reason for this:it minimizes the chances of having on display bad tempers.]]
* Thanks to the Internet, putting a real name to a screen name or e-mail address can lead to all sorts of unpleasantness coming to light.
** Unless your name is exceptionally generic such that there are twelve people in your home country alone with your exact combination and spelling of first name and last name ("Robert Smith" in the United States for instance). But if they also have a general location...
** On MySpace, there is an option you can enable that requires people adding you to know your last name or e-mail address.
** Encyclopedia Dramatica, for all its moral ambiguity, doesn't allow you [[UnusualEuphemism to show them your pokemans]] either. They even have their own [[https://encyclopediadramatica.se/Real_name article]] for this trope.
** General consensus is that the best way to make a troll stop is to call them out by their full name. more thorough retaliation involves phone numbers, addresses, class schedules, friends and relatives, and photos. Collectively these are known as "dox" and to release this information is to known as "dropping dox."
*** Though this is risky business for the namer. Many forums have strict rules against posting the personal information of others to prevent cyber-bullying (this is in fact a common harassment tactic used by trolls). The best way to use this against trolls it to reveal small kernels of information at a time, things that let the troll know that ''you'' know who they are, but without fully revealing their identity to others.
* Whether a type of organism is assigned its own species-level taxonomic name or not can be the deciding factor in whether it is entitled to protection under the Endangered Species Act. The future of the North American red wolf grew far less secure when it was mistakenly suspected to be a hybrid of timber wolf and coyote, hence not necessarily an endangered "species" in its own right.
* A variety of cultures still believe that names have power, and often people are given a name for daily use in order to keep their "true" name sacred.
** In certain rural locales in the Philippines, sickly children are believed to be targeted by TheFairFolk, and as such are given a "second baptism" in an attempt to throw the Fae off. This ends up sometimes with a person being known by his legal name in the city and by his second name to his folks who stayed on the farm / island.
** This is true of some Native American peoples. Some give a child an unpleasant name at birth (to trick envious spirits), and then a more appropriate name later on. The Diné (Navajo) have a true name ('war name')—generally known only to their maternal grandparents, who gave it, and their medicine man—and go by another name for everyday purposes. The Navajo also taboo naming people or pets after dangerous animals, because calling for your dog, 'Bear', is also [[BearsAreBadNews calling bears to you]].
* In the United States, one's Social Security Number is effectively a TrueName. They are designed to be unique, used only when unambiguous identification is necessary, and if someone else gets it they can cause some problems.
** And in many countries who practice ID cards, the ID card number.
* The [[http://rationalwiki.org/wiki/Sovereign_citizen "sovereign citizen"]]/[[http://rationalwiki.org/wiki/Freeman_on_the_land "freeman on the land"]] movements hold that as the government and the courts do not use what they say is their True Name, those entities have no authority over their members. (Their True Names are some variant of their legal name, such as "John of the family Smith," "John of Smith" or even "John: Smith.") As the number of "citizens"/"freemen" who have lost legal cases or been jailed attests, they are wrong.
* If you call someone by their name, they will usually stop for a moment to hear what else you have to say. However, if this power is abused, it will become less effective.
** One of the more puzzling phenomena in experimental psychology is [[http://en.wikipedia.org/wiki/Cocktail_party_effect people's ability to hear their own name being mentioned in a conversation across the room]] - even when they can't hear any other part of that conversation.
* Because religious intolerance has and still exists, part of Gerald Gardner's "Old Laws" for Wicca touches upon persecution and the need for secrecy and the usage of names at rites. ''"And while there, none shall say whence they come, or give their true names."''
* The {{Creator/Confuci|us}}an doctrine of the "Rectification of Names", which can be summed up in the proverb "The Beginning of Wisdom lies in calling things by their proper names." It's purpose was to prevent PoorCommunicationKills, which Confucius believed would snowball into [[ApocalypseHow societal collapse]] if left unchecked.
* In programming, if you know the full name of any object, you can force it do whatever you want that's within its power. What's more, if you know the full name of a class, you can extend it or create a subclass of it to give it the power to do whatever you want, create an object, and - using the full name of the object you've created - force it to do whatever you want that's within the power that you've given it.
** In part for this reason, its standard practice to make the names of your variables and certain internal functions private, giving other developers access to their internal workings in a controlled fashion through public functions designed for that purpose.
* Why else do you think mothers everywhere use the FullNameUltimatum?
* Military service numbers come under this, particularly as there are usually several cases of NamesTheSame.
* In certain cultures, it's rude to call someone by their given name unless you have some intimate connection to them ( family, lovers, etc.), and it's preferred you call them by their family name.