-> ''"You don't need a master... or do you choose your own master? Do we control them, or do they control us?"''
-->-- '''Schwartzwald''', ''Anime/TheBigO''

It is a truth universally acknowledged that weapons are just as capable of [[TheChooserOfTheOne choosing owners]] as people are of choosing weapons. If you're an aspiring EvilOverlord trying to TakeOverTheWorld, what's the one thing more frustrating than needing a ClingyMacGuffin that you just cannot steal from TheHero? Needing a weapon or magical artifact that you ''can'' steal, but it still won't do you any good. For some {{Empathic Weapon}}s, [[PossessionImpliesMastery Possession most definitely does not imply Mastery]]. Loyal Phlebotinum refuses to work for anyone but its [[ChosenOne owner]], no matter who else steals, wins, or accidentally comes across it. The owner does not even necessarily have to [[RefusalOfTheCall approve of this choice]], but {{Synchronization}} usually prevents that, making you inexplicably feel like this sword is the one you're meant to have, or that this dragon is just a better partner for you than any others.

Some phlebotinum may be loyal to only one specific person, for reasons ranging from ancestry to [[BecauseDestinySaysSo destiny]]. Or it may just be loyal only to [[OnlyTheChosenMayWield someone worthy enough]], which usually involves [[VirginPower virginity]] or [[IncorruptiblePurePureness purity of heart]] or the like. Names, [[TalkingWeapon voices]], sentience, and/or a {{psychic link}} that allows the owner to find it when lost are possible but not universal traits.

Variations include:
* {{Mons}}, {{Cool Pet}}s, {{Ridiculously Human Robot}}s, and other {{Attack Animal}}s who only allow a master worthy of owning such a creature to tame them.
* [[TheGirlWhoFitsThisSlipper Articles of clothing that can only be worn by someone who fits some sort of criteria]].
* Literal and inverted [[WeaponOfChoice Weapons of Choice]].

Be forewarned that such devices can [[SelfGuardingPhlebotinum actively discourage unauthorized people from using them]] -- typically in the form of a painful zap. If a desperate villain is willing to risk this, the only options are:

* Destroy it so at least that meddlesome hero no longer has its advantage (he's probably [[YoureNothingWithoutYourPhlebotinum nothing without his phlebotinum]], anyway).
* Blackmail TheHero into using it for you (hold the LoveInterest at gunpoint, dangle helpless children over a SharkPool, etc.).
* Hope that its loyalty will shift under the rules of YouKillItYouBoughtIt (no guarantee).

SubTrope of SituationalSword and PhlebotinumHandlingRequirements. Contrast SlipperyMacGuffin, which will serve you only for as long as it suits it before abandoning you.



[[folder:Anime & Manga]]
* In ''Manga/DGrayMan'', Innocence is so loyal it won't let anyone besides its unique accomodator wield it. If you try to force the synchronization nonetheless, it will leave you crippled, blind, or simply dead.
* In the ''Anime/TenchiMuyo'' [=OAVs=], the Master Key/Tenchi-ken is like this, as it can only be used by Juraians of royal blood. This is why Ryoko couldn't take her gems back and why Ayeka used the key as a torture device.
* The Org from ''Bulge of the Battlestar'', also known as ''Sensei no Bulge'', a mythical royal weapon that can only be used by certain members of the royal family.
* ''Anime/TheVisionOfEscaflowne'': The guymelef Escaflowne will only work for Van Fannel, because his blood was mixed with its energist crystal.
* Samehada, Kisame's sword in ''Manga/{{Naruto}}'', which sprouts spikes from its handle if someone else tries to use it. [[spoiler:Not too loyal though, as it will readily switch sides to whoever can feed it more chakra.]]
* The Kaleidosticks in ''Manga/FateKaleidLinerPrismaIllya'': Much to the annoyance of Rin and Luvia, their Kaledosticks decided that they wanted new owners... while the both of them were using the wands to fly in mid-air.
* The Digivices, crests, Digi-eggs, etc. of the various ''Franchise/{{Digimon}}'' series (and the Digimon themselves).
* ''Manga/InuYasha'': Several of weapons fit this trope.
** Tessaiga initially appears to be this, requiring compassion and half-human, half-youkai heritage to use so only Inuyasha can wield it. Then it seems to be subverted when Sesshomaru reveals he can use it more easily than Inuyasha can -- it's simply the youkai-repelling barrier that prevents him from doing so. This fact is what keeps the true ownership of the sword from being properly decided between the two brothers for a long time until eventually Tessaiga gives Sesshomaru the proof he seeks in a DieOrFly test of Inuyasha's worth -- every time Sesshomaru steals Tessaiga's power, the power immediately returns to Inuyasha.
** A more straight-forward example is [[EvilWeapon Toukijin]] who is so powerful and evil not even [[UltimateBlacksmith Toutousai]] can approach it. Sesshomaru overcomes the blade's evil will easily and the sword obeys him loyally from that point [[spoiler:until the day it's destroyed -- ironically by the strength of Sesshomaru's compassion]].
** Tenseiga is also this. It accepts only Sesshomaru as its true master even though Sesshomaru doesn't want it at all. [[spoiler:Even when he deliberately shatters the blade and discards it, the sword ends up reforging itself and landing back on the ground near Sesshomaru. The only reason Tenseiga is not a ClingyMacGuffin is because it can be physically separated from Sesshomaru. It just won't stay separated.]]
* The Escudo weapons in ''Manga/MagicKnightRayearth'', to the point that Hikaru, Umi, and Fuu can't even use each others' weapons. Hikaru's sword burns anyone besides Hikaru who tries to wield it, Umi's sword turns into water and cannot be picked up by anyone except Umi, and Fuu's sword becomes ridiculously heavy when anyone but her tries to use it.
* ''Anime/TheTwelveKingdoms'':
** Royal Treasure-type artifacts answer only to their proper ruler. The sword that Nakajima receives near the beginning is one of these -- in her hands, it can slay Yokai, while another cannot even draw it from its sheath. (Later, she is forced to destroy the sheath, so anyone can draw it -- but it's still just an ordinary sword in their hands.) This property ends up being quite important, since her possession of and ability with the sword proves her royal status.
** Youkai themselves can be tamed by a Kirin, through a process that largely boils down to a staring contest. If the Kirin perseveres and the Youkai submits, the Kirin recites a sutra and gives the Youkai a name. Failure might result in the Kirin being eaten.
* ''Anime/NeonGenesisEvangelion'': After the dummy plug incident, Unit-01 won't work for anyone but Shinji. The Evangelions generally don't work very well for anyone other than their designated pilot. NERV does experiment with switching pilots into different Evas, but it doesn't accomplish much except making Unit-00 go berserk (again) when Shinji is placed in it. Subverted with Kaworu: since he is [[spoiler:an angel, he can control any Eva against its will so long as its soul has become too weak to resist.]]
* ''LightNovel/ACertainMagicalIndex'': Aleister Crowley is capable of wielding an artifact known as "The Blasting Rod". Its exact capabilities aren't known, but it did [[spoiler:nearly kill Fiamma of the Right without effort]]. The Blasting Rod is said to follow Crowley out of "pure respect", though exactly what he did to gain its respect is not known.
* The Egyptian God Cards in ''Anime/YuGiOh'' can only be used safely by certain duelists with birthrights that give them approval by the gods themselves; anyone else who tries to use one (or even a counterfeit version of one) risks death, madness, [[FateWorseThanDeath or even worse]]. Known duelists who can use them safely are Marik Ishtar (the heir to a bloodline of sacred tomb-keepers), Seto Kaiba (the reincarnation of Priest Seto, the advisor to the Pharaoh), Yugi (whose SpiritAdvisor ''is'' the Pharaoh), and Jaden Yuki (the reincarnation of the Supreme King).
* The Cloths in ''Anime/SaintSeiya'' are this. Every single of them are outright stated to be sentient beings that must be revived with blood if damaged beyond repair, to have a will of their own, and the Gold Cloths have been proven to have outright will and UndyingLoyalty to Athena. Most prominent examples would be Aiolos' Sagittarius Cloth who could act of its own will (it's outright stated Aiolos' soul lives on in the Cloth) and hopped more than once to save Seiya, Deathmask's Cancer Cloth who decided it wouldn't stand anymore for its bearer's [[WouldHarmAChild atrocious acts]] and [[MightMakesRight outright betrayal of Athena]], or Anime-only Gemini Cloth separating itself from Saga as he was about to land a blow on Athena.

[[folder:Comic Books]]
* ''Franchise/GreenLantern'':
** When Green Lantern Abin Sur is dying, he commands his power ring to find and fetch a suitable replacement. It brings test pilot Hal Jordan, who takes up the ring.
** The comics have been highly inconsistent with regard to who can wield a ring. In some stories, only a person who is courageous and has great integrity can use a ring. According to Lex Luthor, "The damn thing's fueled by honesty." However, other stories have entire plots built around a villainous or otherwise unworthy person coming into possession of a ring, usually thanks to PlotInducedStupidity. Though it actually is fueled by willpower, which is neutral in the emotive spectrum.
** When Kyle Rayner was the ''only'' Green Lantern, the ring only worked for him, as former Green Lanterns quickly discovered. Later, he managed to amp up its abilities, so he could control it even if someone else was wearing it.
** The ''original'' Green Lantern's (Alan Scott's) ring put a really nasty spin on this: if worn by someone with malevolent intent, it would '''kill them'''.
* The weapons used by ComicBook/JudgeDredd and his colleagues are equipped with biometric scanners and each can only be used by its registered owner, they explode violently otherwise.
* In ''ComicBook/THUNDERAgents'', the belt that gives Dynamo his powers has to be carefully calibrated to him; if anybody else uses it, the effect will be misaligned and they'll be torn apart.
* MarvelUniverse: ComicBook/TheMightyThor's hammer can generally only be wielded by Thor. Anyone else trying to pick it up will find it impossibly heavy -- even the ComicBook/IncredibleHulk! [[CrossOver Or even]] Franchise/{{Superman}}. However, it's not '''completely''' exclusive, and on a handful of occasions, a worthy and properly-motivated hero (and [[WesternAnimation/UltimateAvengers one specific version]] of the aforementioned Hulk) has managed to pick it up and use it. This is (as one of the few things about him) fairly accurate to the myth.
-->"If he be worthy..."
** Such people have included Wonder Woman during the Marvel vs. DC crossover (though she wouldn't fight Storm with it, as she considered it an unfair advantage), Magneto (though it's never sufficiently explained why), [[TheRealHeroes and an ordinary, non-superpowered EMT worker]] who handed back to Thor during the cleanup of a major fight.
* ComicBook/IronMan's armors are equipped with a neura-link control system that is specifically calibrated for Stark. Anyone else who uses the armor for an extended period of time for months will develop severe neurological problems, such as what happens to [[ComicBook/WarMachine Jim Rhodes]] when he subbed for Stark. He later gets a War Machine suit that is properly attuned to him.
* Justified in ''ComicBook/CreatureTech'': Dr. Ong determines that the alien symbiote is sapient and capable of moral reasoning, and gambles on it preferring him as a host to [[BigBad Jameson]].
* In ''ComicBook/UltimateSpiderMan'', the Venom suit, in this continuity a creation of Richard Parker and Edward Brock Sr., is engineered to only work properly with a certain person's DNA: namely, Richard Parker's. So when someone else wears the suit, it starts ''eating them alive'', forcing them to feed others to it to survive.
* ''Comicbook/{{Empowered}}'''s super suit only works with the titular heroine.

[[folder:Fan Works]]
* ''Fanfic/WithStringsAttached''
** George's ring. He doesn't find this out until it's forcibly removed from him, which is like having his soul's arm ripped off. Later he realizes that he's bonded with the ring and it won't work for anyone else. It's probably not an EmpathicWeapon, though it can hop of its own volition onto his finger from about a foot away. He can also sense it from far away.
** John's Kansael as well. This one's definitely an EmpathicWeapon. It likes him. No... it ''loves'' him. And it's impossible to remove without great care, or [[spoiler:Brox and Co.]] would've simply cut it out of his chest in Ehndris.
* In ''Fanfic/TheKeysStandAlone: The Soft World'', the Kansael's love becomes both useful and annoying, like when it pisses John off by dismissing the others as unimportant, but it also saves his bacon when it gets so furious at him that its anger temporarily scours out the telepaths trying to take over his mind.

[[folder:Films -- Animation]]
* Twilight Sparkle's crown (one of the Elements of Harmony) in ''WesternAnimation/MyLittlePonyEquestriaGirls''. Even when Sunset Shimmer is wearing it, Twilight can still use its power to defeat her.
-->'''Twilight Sparkle:''' The crown may be upon your head, Sunset Shimmer, but you cannot wield it, because you do not possess the most powerful magic of all: the magic of friendship!

[[folder:Films -- Live-Action]]
* ''Film/{{Avatar}}'':
-->'''Neytiri:''' Now you choose your ikran. This you must feel inside. If he also chooses you, move quick like I showed. You will have one chance, Jake.\\
'''Jake Sully:''' How will I know if he chooses me?\\
'''Neytiri:''' He will try to kill you.\\
'''Jake Sully:''' Outstanding.
* In ''Film/District9'' the only ones who can operate the alien weaponry are the aliens themselves. [[spoiler:After being infected by a mysterious black fluid that slowly turns him into a prawn, Wikus]] is able to use them as well, making him a target for MNU, who was anxious to find a way to operate the machinery.
* In ''Film/{{Blade}}'', the hero's sword handle is booby-trapped so that it will shoot silver spikes into the hand of anyone who doesn't know how to disarm it when they grasp it.
* In Tim Burton's ''Film/AliceInWonderland2010'', the Vorpal Blade is the only weapon that can slay the Jabberwock, and ''only'' if Alice uses it to do so. (Whether it is an EmpathicWeapon is unclear, but it likely is; the Caterpillar tells her to simply "hold on" and let it do the work, implying that she simply has to be holding it.)
* In ''Film/ShootEmUp'', the villains have some pistols with fingerprint locking technology.
* Personalized weapons show up a few times in the ''Film/JamesBond'' films:
** In ''Film/LicenceToKill'', Bond is issued a sniper rifle with fingerprint scanners on the handle, preventing anyone but him from firing it. It comes in handy when assassins try to use the gun against him.
** In ''Film/{{Skyfall}}'', Q issues Bond with a [[WeaponOfChoice Walther PPK/S]] coded to his palmprint.
--->'''Q:''' Less of a random killing machine, more of a personal statement.
* ''Film/JurassicWorld'': Hoskins thinks this can be done with raptors, by eliminating rogues and promoting loyal bloodlines. The people who ''actually'' work with raptors just ask him if he actually listens to himself when he talks.

* In the ''Literature/LoneWolf'' gamebook series, the [[InfinityPlusOneSword Sommerswerd]] can only be used to its full potential by a Kai Lord, like the eponymous hero, or a member of the royal house of Sommerlund. If wielded in combat by anyone else, it is said that its power will fade and be lost forever. Furthermore, if a truly evil creature makes the mistake of just holding the sword -- as an ugly dwarf servant of Lord Zahda painfully discovers in ''Castle Death'' -- it will [[{{Fingore}} cost it a few fingers]].
* ''The Golden Sword of Dragonwalk'' has an example, though a little surprisingly it's not the titular magic sword. Instead it's the sword wielded by potential sidekick Elkar, which traps anyone who tries to steal it.

* {{Magic Wand}}s in the ''Literature/HarryPotter'' universe. According to wand-maker Ollivander, "The wand chooses the wizard... And, of course, you will never get such good results with another wizard's wand." YouKillItYouBoughtIt applies for the Elder Wand, [[spoiler:or at least that's the general understanding. Actually it's ''defeating'' that is strictly necessary. A nonlethal defeat works.]] The Elder Wand didn't work [[spoiler:for Voldemort because he killed Snape for the wand, but it was Draco that actually defeated Dumbledore]]. It worked for [[spoiler: Harry because Harry had defeated Draco after Draco defeated Dumbledore]], and [[spoiler:Snape wouldn't have been the Master of the Wand either way because he killed Dumbledore on his orders]]. This is also seen when Hermione tries to use [[spoiler:Bellatrix's]] wand after she stole it without defeating her first. Hermione can't make the wand work well for her and feels revulsion when she tries. She claims the wand feels too much like a piece of [[spoiler:Bellatrix]].
* Mendanbar's sword in Patricia Wrede's ''Literature/EnchantedForestChronicles'': It will only allow itself to be held by the King of the Enchanted Forest or a member of his family. It is innately linked to the forest's magic and in choosing its next bearer when the old one dies, it also selects the next king (who, due to that link, [[AuthorityEqualsAsskicking promptly inherits an enormous amount of magical power on top of the title]] -- wouldn't do to have a spell-less leader of an innately magical country, after all).
* In the ''Literature/DragonridersOfPern'' series, each dragon hatchling chooses its future rider.
* ''Literature/MerryGentry'': Magical items of Faerie -- that have been lost for centuries -- keep appearing around Merry, and ones that supposedly lost their magic are coming to life in her hands.
* ''Literature/{{Discworld}}'':
** Wizard's staffs, most notably in ''Discworld/EqualRites'', and ''Discworld/{{Sourcery}}'' (where the Sourcerer's staff bites another wizard who touches it).
** Also, the only way to get rid of the incredibly obedient and loyal Luggage is to command it to be owned by someone else.
* Dragons in the ''Literature/{{Temeraire}}'' series can choose at birth to bond with a specific person. In the British Aerial Corps (and presumably in most other countries), the human military leaders try to influence the selection by choosing beforehand who gets to be present at the hatching, but sometimes the dragon refuses to choose anyone (and is therefore sent to the breeding grounds rather than into combat), or chooses someone other than the proffered candidate (as with Laurence and Temeraire, though that was a special case; the egg had been captured in a naval battle and hatched in transit). There is even a specific breed of dragon that will only bond with women. Since dragons live much longer than humans, most of them will have multiple human partners, usually preferring the children of their first partner.
* The Orb of Aldur from ''Literature/TheBelgariad'', loyal towards the god Aldur and the descendants of Riva Iron-Grip. And, apparently, the innocent Errand. It was once used by a (different, mad) god to crack the world, and it's NOT interested in being misused again, so hands off unless you're one of the few beings it trusts.
* The sword Need from the ''Literature/HeraldsOfValdemar'' series is a powerful EmpathicWeapon that binds itself to specific women who are about to set off on a life of danger and adventure. It passes itself from bearer to bearer by glowing brightly when handed to its intended recipient. Later it's revealed that Need is more than merely empathic; [[spoiler:she's the soul of an ancient warrior/mage-smith bound into the blade by magic]].
* In ''Literature/{{Cryoburn}}'', Armsman Roic's stunner is designed so it will only fire if he's holding it. In earlier works in the series, all stunners are generic.
* In the ''Literature/{{Lensman}}'' series, the Arisians choose suitable Lensmen, and make a Lens especially for each one. If anyone else tries to wear the Lens, it causes excruciating pain, and quickly kills him.
* In ''Literature/SongOfTheLioness'', there's the Dominion Jewel, which can only be wielded by a true ruler. In this case, King Jonathan. As a double example, it will inevitably revert to its creator, Chitral, at some point to be sought and won again.
* ''Literature/TheQueensThief'' has Hamiathes's Gift, which will not work for the person who has stolen it; it has to be freely given.
* In ''Literature/TheStormlightArchive'', the Ryshadium are a breed of intelligent and powerful {{Cool Horse}}s who choose their riders and do so with considerable discrimination.
* ''Literature/TheLordOfTheRings'': This is the primary reason brought up against trying to use the One Ring as a weapon against Sauron: the Ring is loyal to Sauron only. It does allow its current Bearer to access some of its powers, but it always seems to mysteriously fail or "slip off" at inopportune moments, making it a dangerous thing to rely on. It is implied that a powerful enough being might be able to ''force'' the Ring to work for them, but this is never attempted (too risky if it fails... and arguably even more risky [[TheCorruption if it succeeds]]).
-->'''Aragorn:''' You cannot wield it! None of us can. The One Ring answers to Sauron alone.
* Creator/VladimirVasilyev's novelization of ''[[{{VideoGame/XCOM}} X-COM]]'' explains the reason why X-COM soldiers can't use alien weapons before they're researched. Apparently, they're all biometrically locked to specific DNA. After a weapon is researched, soldiers are instructed how to override the biometric lock and enter their own DNA into the weapon's database. One civilian hacker is notable for picking up a killed Muton's plasma rifle during a terror attack and figuring out how to reprogram the biometric lock himself, then going to town on the invaders using the sheer power of IKnowMortalKombat. He later asks to join the organization and becomes a fairly decent soldier.
* The Eye of Onyx from ''Literature/WingsOfFire'' is revealed to explode anyone that it doesn't choose as the rightful queen. This usually just makes sure the [[=SandWing's=]] [[ChallengingTheChief usual method of choosing successors]] runs smoothly, and its absence is a large part of why the three [=SandWing=] heirs end up fighting each other in a civil war.
* ''Literature/{{Wolfhound}}'''s sword Sunflame is an EmpathicWeapon and ClingyMacGuffin (of the good kind). It subliminally suggested him its preferred name, communicated with him in his dreams on occasion, returned (or was returned by the ThePowersThatBe) to him when lost or used to buy a man out of slavery, and it even had some limited degree of agency, such as when a thug stole it and tried to use it, it got hopelessly stuck in a log the first chance it got and only unstuck for Wolfhound.
* In ''Literature/{{Armor}}'', PoweredArmor suits are tailor-made to prevent them from horribly killing their wearers-if its joints don't match yours perfectly, it'll break whatever bones it has to to move, and its so tight that part of the training is showing a surgical record of a guy who tried to wear a cricifix in his suit, which got crushed into his sternum. As a side-effect, they can't be worn by anyone else. Even if someone is the correct user, if they've gotten too fat, it still sucks to wear.

[[folder:Live-Action TV]]
* ''Series/DoctorWho'': The TARDIS is [[LivingShip alive]] and has a psychic link with the Doctor, so don't think she's going to leave her Time Lord without a fight. This is very much DependingOnTheWriter: the Master has gained control of the TARDIS on several occasions. In the classic series the Doctor has sometimes claimed the TARDIS has "isomorphic controls" that prevent unauthorised users, but on other occasions it's been suggested this is just a bluff (in "A Christmas Carol", when he's told the weather machine has isomorphic controls he says there's no such thing - and is wrong). The Master's laser screwdriver also has isomorphic controls in "Last of the Time Lords".
* As different ''Franchise/PowerRangers'' series work differently, the requirements for making the suits work is also different. The series that most have it as a plot point are:
** ''Series/PowerRangersTimeForce'' -- they link to the DNA of the user, ''and'' they only work once the red one has been activated. They had to find an ancestor of their deceased leader before they could power up. Figuring out [[HowDoIShotWeb how to shot web]] was harder for them than for most any other team. But that's what you get when you steal the morphers and go on an unauthorized mission.
** ''Series/PowerRangersLostGalaxy'' -- the Quasar Sabers could only be wielded by the worthy, and went nuts when a MonsterOfTheWeek tried to use them.
** In ''Series/PowerRangersDinoThunder,'' Dino Gems also choose their users, and non-suited powers can be used even if the gem has been taken. However, no suits without the morpher (which is powered by the gem).
** The original dinosaur Power Coins from ''Series/MightyMorphinPowerRangers'' were like this. In order to change users without the current ones dying first, an artifact called the Sword of Light is required. So when it was time to [[PassingTheTorch pass the torch]], the Rangers had to journey to an abandoned planet to retrieve said sword.
* The super suit in ''Series/TheGreatestAmericanHero'' will only work for the person chosen by its alien creators.
* The Franchise/StargateVerse includes a few notable examples:
** In ''Series/StargateSG1'', several pieces of Goa'uld technology will only work for someone with naqadah in the bloodstream -- namely Goa'uld, Tok'ra or [[PuppeteerParasite former hosts]]. This include the weapon hand-device, the healing hand-device, and quite likely the [[DeflectorShields personal shields]] and {{invisibility cloak}}s too, as they are never seen used by Jaffa. This aims essentially at enforcing the belief in the mystical powers of the Goa'uld, as they pass off those effects as divine magic.
** Likewise, many artefacts of the [[{{Precursors}} Ancients]] need to be touched by an Ancient or a human carrier of the "Ancient gene" (probably human descendants of the Ancients that fled from Atlantis) before working. Sometimes, this activation is all that is needed, and the item can then be used by anyone. The [[Series/StargateAtlantis Atlantis expedition]] specifically hired as many gene carriers as they could find, and later managed to circumvent this limitation by inducing the Ancient gene through genic therapy (with variable success, depending on the individual).
** Aris Boch, bounty hunter from the 3x07 episode "Deadman Switch", possesses a gun only he can shoot, with energy projectiles that also happen to pass through the shields he uses to capture people.
* In ''Series/{{Continuum}}'', Kiera's futuretech pistol has a biometric lock that prevents anyone besides her from using it. Attempting to do so results in an "UNAUTHORIZED USER" message and a lethal electric shock. Two people have fallen for it so far, one tricked into it, and the other who was also from the future and [[WhatAnIdiot really should have known better]].
* The Book of Shadows in ''Series/{{Charmed}}'' is repelled by evil. Effects vary from putting up a force field of some sort to simply sliding away if the wrong person tries to pick it up. Paige once had a boyfriend thumb through it to see if it would let him (which he picked up on pretty quickly despite not knowing about the protection). There are ways to get around this, such as taking control of the manor or stealing the Power of Three, but it at least tries to stay loyal to its rightful owners.

[[folder:Myths & Religion]]
* In Myth/NorseMythology, the hammer of Thor would not be wielded by anyone else. It could still be stolen (and is, on at least one occasion), but it's only in the hands of Thor that it turns into a godlike weapon. At least in some versions, that was due to Thor being the only individual strong enough to actually throw the hammer rather than any loyalty on its part.
* Bucephalus was said to only let Alexander the Great ride him. There's a story where Alexander is solely responsible for the creation of Bucephalus, and trained him so that he would only allow him to ride it. (And attached a golden horn to its forehead, just because he wanted a magical sort of horse.) Indeed, no-one could even approach the animal, let alone ride it -- until one fateful day, when King Philip lets his 3-year-old son, also named Alexander (different son from a different wife) to mount the horse. Alexander finds his half-brother riding his horse, and can barely hold in his rage. He decides he has to kill the horse now, because it had accepted another master. His father warns him that you can't be a good king with that kind of attitude (i.e. killing anyone and/or anything that doesn't go your way). Alexander ignores the advice, and there ''are'' consequences in the long run for him....

[[folder:Tabletop Games]]
* In the ''TabletopGame/MutantsAndMasterminds'' RPG, you can take a power feat called Restricted for your devices that does this.
* In ''TabletopGame/{{Champions}}'', when a power is purchased through a Focus (an item required for the power to function), the purchaser has the option of defining the Focus as "keyed" to the character whom it's bought for. In that case, if an enemy gets ahold of the Focus, he can't use it against the character -- but the character's allies can't use it, either.
* ''TabletopGame/DungeonsAndDragons''
** Intelligent weapons greatly prefers to be wielded by characters of the same [[CharacterAlignment alignment]] as them or a close one, and can refuse to use their powers for people who don't agree with their goals. If someone of an ''opposite'' alignement picks up such a weapon, it will likely give the "painful zap" response, the amount of damage depending of the weapon's ego score.
** Some other magic weapons (which may be intelligent or not) have restrictions on the classes or races that can use them. Weapons forged for paladins, for example, will only bestow their full power when wielded by a paladin and no other class, even if LawfulGood. In the hands of unfitting characters, such items will at best perform like average magic weapons, or be non-magical, or could even act like cursed weaponry.
** The 3.5 rules introduced the [[http://www.d20srd.org/srd/variant/magic/legendaryWeapons.htm Legendary Weapons]]. Those magic items only bestow a fraction of their powers to ordinary adventurers; to gradually unlock their full potential, a character must adopt the appropriate "Scion" PrestigeClass and devote most of his or her career advancing in this class.
* Firearms in ''TabletopGame/{{Shadowrun}}'' can be fitted with biometric safeties to prevent them from firing for unauthorized wielders.

[[folder:Video Games]]
* In ''VideoGame/KingdomHearts'', his is true of Keyblades in general. They refuse to be used by anyone other than their chosen wielder (although on occasion they have permitted another Keyblade wielder to use them for brief periods of time, usually someone their own wielder trusts). If they are ever taken away from their wielder, they just teleport right back into his or her hands. This is why the villains never bother trying to steal a Keyblade, as they know it's a pointless exercise. The only exception was seen when Riku took the Keyblade from Sora: Sora was feeling very down and had lost the will to continue, [[EmpathicWeapon so the Keyblade abandoned him]]. When he later gets his drive back and confronts Riku again, the Keyblade returns to his hands immediately.
* Similar to the RealLife entry below, most weapons in the ''VideoGame/MetalGearSolid'' series are programmed to only work for the person that it was issued to. Originally used to justify your inability to loot an automatic rifle off every mook you kill, it becomes a major plot point in the 4th game.
* ''VideoGame/FireEmblem''
** In ''VideoGame/FireEmblemShadowDragonAndTheBladeOfLight'' and its sequels, the Falchion may only be properly wielded by the Hero-King Marth and his descendants, the line of the Exalts. If the blade is wielded by one who does not meet the requirements, they will find it incapable of cutting even a simple log. That there's [[spoiler:another person wielding a second of this one-of-a-kind sword without problems]] in ''VideoGame/FireEmblemAwakening'' is a plot point. [[spoiler:[[TimeTravel The]] [[KidFromTheFuture answer]] [[BadFuture is]] [[MementoMacGuffin probably not]] [[SetRightWhatOnceWentWrong what you were expecting.]]]]
** The Mani Katti in ''VideoGame/FireEmblemTheBlazingBlade'' will only permit itself to be used by Lyn. A bandit who tried to steal it earlier couldn't even remove it from its scabbard.
* Quest artifacts in ''VideoGame/NetHack'' will hurt you if you're not the right class. (Every class has its own quest and artifact, but you can use wishes to get others.) Picking it up, wielding, wearing or using it results in a painful shock that can even kill you on lower levels. (This ''is [=NetHack=]'', after all.) If your alignment does not match the item, it will even refuse to let you pick it up!
* Many, many items in the various Creator/BioWare games (and other similar [[RolePlayingGame RPGs]]) are only usable by certain classes or characters. Especially notable is "Spellweaver" in ''VideoGame/DragonAgeOrigins'', a sword that can only be wielded by an [[MagicKnight Arcane Warrior]].
* In ''VideoGame/KnightsOfTheOldRepublicIITheSithLords'', the player will find a lightsaber crystal called "InsertPlayerNameHere's Crystal" that only the player can wield. As you level up and get KarmaMeter points, you can ask Kreia to "tune" the crystal, increasing its stat bonuses in different ways, based on how you are playing the game. It's unclear what exactly effects it, but its color will change (white, grey, black) with your karma values.
* In the Creator/AGDInteractive ''VideoGame/KingsQuestII'' FanRemake, Neptune's trident is stolen by the evil Sharkees, and King Graham is promised the Water Gem in exchange for getting it back. Sneaking into the Sharkee Palace, Graham comes across the Sharkee King trying intensely to the trident to work, but to no avail, as it is enchanted to only obey people of noble blood and good will. The Sharkee King also knows of this enchantment and it angers him, as he, being the ruler of the Sharkees has the "noble blood" part covered, and since he obviously has the ''[[ComicallyMissingThePoint greatest]]'' will of all underwater creatures, wielding the trident should be a cinch for him. As Graham steals it back, he has no problems with using it for his own protection as he is a king after all and has a good will.
* "Moonthril" weapons in ''VideoGame/KingdomOfLoathing'' are very time-consuming to obtain but extremely powerful. Unfortunately, they bind to their original owner and vaporize when their owner dies... and since the NewGamePlus involves reincarnation they are [[AwesomeButImpractical just not worth it]].
* When Daxter picks up a Dark Eco bomb in the opening of ''VideoGame/JakAndDaxterThePrecursorLegacy'', nothing happens. When Jak touches it, however, it lights up immediately.
* The Master Sword from ''Franchise/TheLegendOfZelda'' series cannot be touched by those with evil hearts, and generally can only be wielded by Link himself.
* In ''VideoGame/PokemonBlackAndWhite'', the "star" Pokémon of the games are bitter rivals who seek trainers to end their feud. The star of the game you're currently playing (Reshiram if ''Black'' or Zekrom if ''White'') chooses you as its trainer, while the other sides with N, the leader [[spoiler:or so we - and he - are led to believe]] of Team Plasma.
** Something similar occurs in [[VideoGame/PokemonBlack2AndWhite2 the sequel]] with Cobalion, Terrakion, and Virizion; when you encounter the three of them, it's clear that they are ''waiting'' for you to battle them. (The storyline mentions a GreatOffscreenWar in which their friend Keldeo was hurt, suggesting that befriending a trainer might be needed to undo the damage.)
* The MagneticWeapon used by the [[VichyEarth ADVENT Trooper]] in ''VideoGame/{{XCOM2}}'' are SmartGun DNA locked to said troopers. Defied by XCOM's creative R&D Department who find a way to remove the DNA lock and build more of these guns.

[[folder:Web Animation]]
* Tucker's energy sword in ''Machinima/RedVsBlue'' binds to him when he first acquires it and won't turn on for anyone else who tries to wield it. This is later shown to be true in general for these swords: the first person who picks it up becomes the only person it will work for. The only way to get it to work for someone else is to kill its current wielder.

[[folder:Web Comics]]
* In ''Webcomic/TheOrderOfTheStick'', the Sapphire Guard uniform is magical and only works for a paladin. Thus, [[spoiler:when Miko becomes a fallen paladin, [[PaintItBlack her armor loses its color and powers]]]].

[[folder:Web Original]]
* ''Literature/{{Phaeton}}'' has the Shield of Eons, which will only work for someone who values the lives of others above their own, Tom values the lives of others to such an extent that the shield will actually appear in his hand if he calls for it. Even if it's on the other side of the planet.

[[folder:Western Animation]]
* {{Lampshaded}} and Discussed in an episode of ''WesternAnimation/TheFairlyOddParents'': Timmy wishes for a "Reset Watch" that lets him travel back in time. After Vicky gets a hold of it, Wanda recommends that whenever he wishes for gadgets like that, he should add the requirement that they only work for him.
-->'''Timmy:''' Wanda, I wish you were a Reset Watch! ''[Wanda glares at him]'' That only works for me!
:: Ultimately, this is how he gets back the other watch -- he claims the Wanda-watch to be much more powerful, tricking Vicki into switching them only for her to find out she can't use it before suffering from a large amount of AmusingInjuries.
* By all appearances, the Omnitrix in the ''WesternAnimation/Ben10'' series: It doesn't work for Vilgax when he steals it in an episode of ''[[WesternAnimation/Ben10AlienForce Alien Force]]'', and after it gets {{Ret Con}}ned to being easy to remove from its host, Azmuth is still only reluctantly resigned to letting Ben keep it. It can only be that he knows that the watch chose Ben and won't work (at least as well) for anyone else. He originally intended it for [[MissedTheCall Ben's grandfather Max]], but there's no rule saying an EmpathicWeapon's choice in owner can't conflict with its creator's choice. Furthermore, human DNA is not all that different from one another (a plot point in an ''Omniverse'' episode, which is probably why Ben (and in some alt timelines Gwen) can use it pretty well.
* In an episode of ''WesternAnimation/SamuraiJack'', Aku manages to disarm Jack and tries to kill him with his own sword. It harmlessly bounces off of him because it cannot harm anyone who is pure of heart.
* ''WesternAnimation/AdventuresOfTheGalaxyRangers'': While the other three {{Mechanical Horse}}s of the Galaxy Rangers are okay with having a teammate other than their "designated" one ride them (Doc and Niko trade off on Mel and Voyager several times), Triton is ''very'' forthright with the fact that only Shane can ride him, only making an exception on Shane's explicit orders.
* ''Franchise/{{Transformers}}'':
** The Autobot Matrix of Leadership could be said to be like this. While it is said that the Matrix would "light their (the Autobots') darkest hour", the Matrix chose to empower Hot Rod (thus turning him into Rodimus Prime) and not Ultra Magnus, which may mean that it still only responds to certain individuals and not just any Autobot.
** ''WesternAnimation/TransformersPrime'' has the [[AbsurdlySharpBlade Star Saber]], and the Forge of Solus Prime, can only be wielded by a Prime. [[spoiler: Megatron gets around this by surgically replacing his arm with that of a previous prime and use the Forge.]]
* The Hearts of the World (Candracar, Meridian, Zamballa, Earth) from ''WesternAnimation/{{WITCH}}'' are like this. They can only be used by a chosen person, can only be given up willingly by said chosen and if it's taken by force, it returns to them. Unfortunately for Elyon and Kadma (bearers of the Heart of Meridian and Zamballa, respectively), Nerissa used this to her fullest.
* ''WesternAnimation/ThunderCats'': While the Sword of Omens is only ever to be wielded by the lord of the Thundercats, Lion-O. it has been used by other characters of "pure spirit" on occasion; Willa of the warrior maidens once used "Sight Beyond Sight" in the episode "Garden of Delights", and the Sword has also responded to Lynx-O in "Ravage Island". In the episode "Tight Squeeze", Snarf used the Sword of Omens with no problem.
* Like in the original, in ''WesternAnimation/ThunderCats2011'' only the protagonist Lion-O appears able to utilize the Sword Of Omens' "[[{{seers}} Sight Beyond Sight]]" Though others may take custody of the blade, it's enchanted against "being touched by the hands of evil," which appears to be a failsafe against BigBad Mumm-Ra's using it. Curiously, Slithe holds the sword just fine [[spoiler:after Lion-O is killed in "Trials of Lion-O".]]
* WesternAnimation/FelixTheCat's [[WesternAnimation/JoeOrioloFelixTheCat Magic Bag of Tricks]] is [[SentientPhlebotinum implied to be sentient]], and most of the time, it works for Felix and ''only'' Felix. The handful of times The Professor manages to get his hands on it, the bag will violently resist every attempt he makes to use it. Felix can even whistle for it to come back to his side—in "Felix Out West", it even morphs into a rabbit and hops back to Felix, licking him on the face like a dog before it turns back to normal. With that said, Poindexter did figure out how to use the Bag in [[Recap/JoeOrioloFelixTheCat1x64MartinTheMartianMeetsFelixTheCat "Martin the Martian Meets Felix the Cat"]], but that was only so he turn it into a portal to Mars so he could meet Martin, so it's not that Professor is outright incapable of using it so much as the bag knows he's a bad guy and won't allow him to exploit its powers.
* The Great Book of Gummi in ''WesternAnimation/AdventuresOfTheGummiBears'' has layers upon layers of conditions to protect its magic from unauthorized users. First, it can only be unlocked with a Gummi medallion. Once it's unlocked, it can only be physically opened by a Gummi Bear or someone wearing a Gummi medallion. Once it's opened, the same conditions are required to make any of the spells work for you. Finally, even if you can use the magic, you cannot use it to harm a Gummi Bear in any way -- try, and it might be the last thing you ever do. Happy reading! Best seen in the episode "For Whom the Spell Holds", where we get to see all of these protective traits in action, one after the other. Zorlock the EvilSorcerer has so much trouble opening the Book that it actually crushes him under its front cover, he and his rat-ogre are vividly electrocuted when they try to just take the medallion from Zummi, and Zorlock ends up being HoistByHisOwnPetard when he conjures up a destructive spell and tries to blast the Gummis with it, only for it to attack ''him'' instead. Another good example is the series finale when Duke Igthorn attempts to chisel the book open despite Zummi's warnings. Cue the book blasting the Duke across the room in a magical blast when Igthorn expectedly ignores him.

[[folder:Real Life]]
* A firearms company has been working on a gun that won't fire if it is stolen and turned against its owner. At the moment it just sometimes refuses to fire even for the intended owner. Fingerprint lock gun technology is possible if [[AwesomeButImpractical not practical]] currently.
* Devices with physical or digital locks can ideally be used only by the authorized holder of a key or password. Of course, this can be subverted if the owner loses the key or [[ThePasswordIsAlwaysSwordfish chooses a bad password]].
* Some modern smartphones can actually be unlocked by fingerprint, as can many models of laptop as a built-in capability. This means even if the phone is stolen or confiscated or lost, nobody but its owner can actually access it.