History Main / LoyalPhlebotinum

* 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.

* 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.

* In "[[https://archiveofourown.org/works/49660204/ Heroes Stand United]]", the Snarts and Mick Rory step in to protect a young girl from being assassinated by Count Vladek as part of his attempted coup. Vladek attempts to kill Leonard Snart using Snart's own cold gun, but unfortunately for the count Snart had included biometric security in the weapon, with the result that Vladek freezes his own hand and drops the gun.

** ''Series/PowerRangersLostGalaxy'' -- the Quasar Sabers could only be wielded by the worthy, and went nuts when a MonsterOfTheWeek tried to use them.

** 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.

* 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.

* In ''Franchise/KingdomHearts'', this 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.

* 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.)

* 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.

* Franchise/MarvelUniverse: [[ComicBook/TheMightyThor Thor]]'s hammer can generally only be wielded by Thor. Anyone else trying to pick it up will find it impossibly heavy -- even the [[ComicBook/TheIncredibleHulk Hulk]]! [[{{Crossover}} Or even]] ComicBook/{{Superman}} -- which is implied to be because he abides by ThouShaltNotKill, while being Worthy in this context means being willing to kill if necessary.[[note]]Odin nevertheless temporarily lifted it at the climax of ''ComicBook/JLAAvengers'' to allow Superman to wield it, along with Captain America's shield, making the most awesome cover in the history of comics).[[/note]] 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 one of the few things about him that's actually fairly accurate to the myth.

* ''ComicBook/RequiemVampireKnight'': When Claudia picks up Requiem's sword and use it against him, the sword tells her to "[[CurseCutShort get f-]]".
* The "Dragon Claw" ComicBook/RichardDragon was given by his sensei is an odd artifact, it only really does anything besides act as a focus for meditation if both its wielder and the ''situation'' calls for it, which is when "something greater than human life is in peril".

** Also from 3.5, the ''Dungeon Master Guide II'' has bonded magic items, which are created through a ritual rather than with the usual item creation feats. The cost is the same as with standard magic items creation, but the magic power imbued only works for the character who'd gone through the ritual. Such items can be already magical or separately enchanted further, but it should be noted that armors and weapons always need at least a +1 enhancement bonus to gain any further magic properties. Thus, if this initial +1 is the magic granted by a ritual, even if later enchanted by a separate spellcaster, all of its magic will be inactive except for the bonded character.

** 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.

* 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).

* 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.

** 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 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.

* ''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.
** Touma's [[AntiMagic Imagine Breaker]] is only usable by him. If his right hand or arm (where the power lies) is cut off, it regenerates and retains the power. This is notable in that the same is not true of the two other people with similar powers.[[note]]Fiamma of the Right lost the ability to control his Holy Right when his right arm was severed, though the power itself remains in his body. Kakeru not only lost his World Rejector when his right hand was cut off, it was outright used by another person who grafted it onto their body.[[/note]]

* This is why Sousuke winds up as the Arbalest's dedicated pilot in ''LightNovel/FullMetalPanic'' even though Mithril technically has superior and more talented Arm Slave pilots to make use of. Once it was calibrated for his use in an emergency rescue mission, Mithril's engineers discovered the AS's AI refused to work with anyone else and resisted all attempts to reformat it. So now their emotion-driven superweapon can only be activated by a stoic, emotionally stunted teenager, and absolutely no one is happy with this, especially Sousuke himself.
* ''Manga/InuYasha'': Several of weapons fit this trope.

* ''Franchise/GreenLantern'':

* MarvelUniverse: [[ComicBook/TheMightyThor Thor]]'s hammer can generally only be wielded by Thor. Anyone else trying to pick it up will find it impossibly heavy -- even the [[ComicBook/TheIncredibleHulk Hulk]]! [[CrossOver Or even]] Franchise/{{Superman}} -- which is implied to be because he abides by ThouShaltNotKill, while being Worthy in this context means being willing to kill if necessary [[note]] Odin nevertheless temporarily lifted it at the climax of ''JLA/Avengers'' to allow Superman to wield it, along with Captain America's shield, making the most awesome cover in the history of comics)[[/note]]. 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 one of the few things about him that's actually fairly accurate to the myth.
-->"If he be worthy..."
** Such people have included ComicBook/WonderWoman 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.

* 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 ''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.

* 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.

* 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.
** Ivan Vorpatil also has one in ''Captain Vorpatil's Alliance''. The Imperial Service is in the process of making them standard issue.

* In ''LightNovel/TheUnexploredSummonBloodSign'', the Sword of Truth is so loyal that it actually disobeys its wielder so it can fly off and kill anyone who's hurt her feelings...regardless of whether she actually wants those people dead or not. Most of Volume 9 is about various people, including the wielder, teaming up to stop the Sword from destroying all of existence (which it is fully capable of doing).

* 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 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.

* In ''Film/WarGod'', Guan Yu's trusty, iconic Green Dragon Saber can only be wielded by the hero. The third and last Martian villaim tries stealing the sabre, only to be electrocuted on the spot.

* ''Manga/UshioAndTora'': the Beast Spear. To 99% of people it's just a nice-looking, slightly worn out spear with a large sword-like blade which can't actually cut people. However, once it has picked a wielder, that person and only that will be able to channel it's amazing powers to slay {{youkai}}, slowly losing his/her soul at any usage. After a while, the bond becomes so powerful that the Beast Spear will come to Ushio's hand the second he's in danger, which provides an entertaining manga-only episode where, as he promised to Tora, gets rid of the Spear for one day to give Tora a shot at eating him... [[SuperPersistantPredator only for the Spear to always return to save him, much to Tora's chagrin]].

* ''VideoGame/TheElderScrollsIVOblivion'': The Amulet of Kings, an enchanted pendant that symbolizes the divine right of the Cyrodilic emperors, can only be worn by the imperial bloodline. The PlayerCharacter carries it for safekeeping after the Emperor's murder, but if they try to put it on, it immediately slips off.

* Literal and inverted weapons of choice]].

* {{Mons}}, {{Cool Pet}}s, {{Ridiculously Human Robot}}s, and other {{Attack Animal}}s who only allow a master [[OnlyTheChosenMayRide worthy of owning such a creature to tame them]].

* Literal and inverted [[WeaponOfChoice Weapons of Choice]].

** In ''Film/{{Skyfall}}'', Q issues Bond with a [[WeaponOfChoice Walther PPK/S]] coded to his palmprint.

* The Vampire Killer in the ''VideoGame/{{Castlevania}}'' series is a holy whip that was designed to fight Dracula and his evil forces. But only a member of the Belmont clan can safely wield the whip. Anyone else will have their life drained by it, which was the fate of [[VideoGame/CastlevaniaBloodlines John Morris]], the first non-Belmont who wielded the whip.