->''"Well, we know in other cases with their later technologies that the Ancients used sensors that restricted access by detecting specific genetic markers."''
-->-- '''Dr. Dale Volker''', "Human", ''Series/StargateUniverse''

An item, MacGuffin, or other such that can only be used by someone who is, for example, [[OnlyThePureOfHeart pure of heart]], a certain age, part of a certain family/bloodline, or has some rare property that only certain people have. This does not include needing a password, key, or other such item.

In other words, the requirement to use it has to have more to do with the actual plot, although the actual importance of said requirement does not matter. Sometimes the requirement is a background detail, other times it has a major effect on the story.

Supertrope to:
* LevelLockedLoot
* LoyalPhlebotinum
* OnlyTheChosenMayWield
* OnlyGoodPeopleMayPass
* OnlyThePureOfHeart
* PhlebotinumHandlingEquipment

SisterTrope to OperatorIncompatibility. Contrast SelfGuardingPhlebotinum, which is when the item protects itself ''against'' people with a certain quality. If a character is the only one in the cast who meets the requirements, they might also be TheTeamBenefactor.



[[folder:Anime & Manga]]
* ''Franchise/{{Gundam}}'':
** Various types of mobile suits are made specifically for Newtypes.
** The RX-0 Unicorn Gundam from ''Anime/MobileSuitGundamUnicorn'' can only be piloted by someone who has a noble heart, and has a noble reason to pilot it. The pilot also has to be a Newtype.
* In ''Manga/{{Naruto}}'', the sword Samehada can only be wielded if [[EmpathicWeapon it likes the taste of the wielder's chakra]].
* ''{{Manga/Barrage}}'': Astro's weapon is described as working only for those who have the qualifications. Initially, it's assumed to be his bravery and pure-heartedness, [[spoiler: but it turns out that it's actually royal blood, which Astro secretly possesses]].
* ''Anime/DarlingInTheFranxx'': [[HumongousMecha Franxx]] cannot be piloted by just any pair - the duo, aside from being opposite genders with good mental sync, must also be naturally compatible. This is taken to an extreme with Zero Two and Strelizia: she can pilot Strelizia solo in an alternate wolflike form if her "stamen" male partner is incapacitated, but still requires the stamen to unlock the Franxx's full combat power, and none of her partners [[spoiler:until Hiro in episode 6]] survived their third sortie because syncing with her a third time killed them.

[[folder:Comic Books]]
* ''ComicBook/TheMightyThor'': "Whosoever holds this hammer, if he be worthy, shall possess the power of Thor." Only a very few people have been able to lift Mjolnir: [[CaptainObvious Thor himself]], ComicBook/BetaRayBill, ComicBook/{{Thunderstrike}}, ComicBook/CaptainAmerica, and the occasional HeroicBystander and/or [[TheRealHeroes emergency worker]]. In the ''ComicBook/JLAAvengers'' IntercontinuityCrossover Franchise/WonderWoman was also found worthy. Franchise/{{Superman}} wasn't, but Odin temporarily removed the enchantment so he could use it.
* ''ComicBook/JudgeDredd'': the Lawgiver guns used by the Judges are specially made so that only a Judge can use them, by testing their DNA upon holding it. If someone that is not authorized to do so uses it, it explodes.

[[folder:Fan Works]]
* In ''[[FanFic/SovereignGFCOrigins Origins]]'', a ''MassEffect''[=/=]''StarWars''[=/=]''VideoGame/{{Borderlands}}''[[spoiler:[=/=]''[=Halo=]'']] MassiveMultiplayerCrossover, certain [[AncientArtifact Ancient Artifacts]] left laying around by NeglectfulPrecursors can only be operated by humans. Said artifacts also specifically recognize Sirens--some to the point where only Sirens can even see the artifact's actual physical form while anyone else (human or otherwise) sees something much more mundane.
* ''Fanfic/DungeonKeeperAmi'': How to activate a Dungeon Heart: From [[https://forums.sufficientvelocity.com/threads/dungeon-keeper-ami-sailor-moon-dungeon-keeper-story-only-thread.30066/#post-6355661 the first chapter]]:
--> The dungeon heart, while not being sentient, reacted according to its programming when it felt itself being accessed. User is intending to use my power to destroy her enemies? Check. User's blood? On the cover, coagulated but present. Check. Strong source of magical power? Oh hell yes! Check.

[[folder:Films -- Live-Action]]
* Lightsabers in ''Franchise/StarWars'' can be effectively wielded only by Force-users, with very few exceptions. This is explained by the weapon's very counter-intuitive balance and preternatural quickness needed to wield it. Only one such exception is in the film canon, General Grievous, and he's a cyborg, with his mechanical precision of movements preventing him from julienning himself with the energy blades. The other film canon non-Force user who tries to handle a lightsaber, Han Solo, is wise enough to only use it to cut open a dead tauntaun. Also noteworthy is that Han is apparently well aware of how easily he could wind up missing chunks of himself, and keeps the hilt close to himself and his elbows tight to avoid swinging the blade around too much and winding up having to change his name to [[{{Pun}} Han Duo.]]
** More recently, Fin wields one in ''Film/TheForceAwakens'' and sort of holds his own, to the annoyance of some fans.
* In ''Film/{{District 9}}'' only prawns can use the prawn superweapons. Thus human Wikus becomes of interest to the authorities when he is infected with alien prawn DNA.
* In ''Film/{{Avatar}}'', each half-human, half-alien Avatar is bound to a particular person's DNA. Jake is only brought along because his twin brother died -- and the highly costly Avatar was meant for his twin brother.

* In ''Literature/LoneWolf'', only a Kai warrior such as Lone Wolf can wield the Sommerswerd. If anyone else tries to wield it, its powers would slowly fade until they were lost forever. The sword will also burn any evil beings who lay hands on it.

* The Franchise/StarWarsExpandedUniverse novel ''Literature/TheCrystalStar'' features a Jedi and Dark Jedi who have lightsabers that [[NoOffButton lack a traditional on/off switch.]] Instead, igniting them requires using the Force to close an internal electrical connection. In the ''Literature/NewJediOrder'' series the Skywalkers have a similar security feature on the bridge airlock of the ''Jade Shadow'': opening the hatch from outside requires use of the Force to manipulate the internal mechanisms; the actual hand-operated latch is nonfunctional.
* Creator/LloydAlexander's ''Literature/TheChroniclesOfPrydain'': Only a member of the House of Llyr, such as Princess Eilonwy, can command the power of her "bauble" (a.k.a. the Golden Pelydryn) and use the House's magical spells.
* The Spear of Telesto in the ''Literature/BloodAngels'' novels can only be wielded by carriers of their Primarch Sanguinius' genes (i.e. just the Blood Angels and their successor chapters). Its [[FireBreathingWeapon flamethrower attack]] will likewise refuse to damage such.
* ''Franchise/HarryPotter'':
** {{Downplayed|Trope}} with wands, which have a certain loyalty to their owners and will not generally operate at full capacity for anyone else. Lore around the Elder Wand, a legendarily powerful item in ''[[Literature/HarryPotterAndTheDeathlyHallows Deathly Hallows]]'', suggested that it can be passed at full, prodigious strength to any person who defeats its last owner. [[spoiler: Despite a string of deaths, the Elder Wand is no more powerful for Voldemort than his usual wand (which isn't saying much given the scale of Voldemort's powers),]] because he misread the chain of succession.[[labelnote:Explanation (MAJOR SPOILER WARNING!)]]What Voldemort doesn't consider is that death is not the only means of defeat--disarmament counts. Furthermore, physical possession of the Elder Wand doesn't matter. Draco Malfoy disarmed Dumbledore prior to the headmaster's death in ''[[Literature/HarryPotterAndTheHalfBloodPrince Half-Blood Prince]]'', and Harry disarmed Draco in ''Deathly Hallows'' which caused ''control'' of the Elder Wand to pass to Harry, even though he never touched the wand itself. Harry in turn reasons in the denouement that he can break the chain of succession for good if he lives to die of old age.[[/labelnote]]
** {{Invoked|Trope}} by Dumbledore in ''[[Literature/HarryPotterAndThePhilosophersStone Philosopher's Stone]]''. [[spoiler:He sets up the Mirror of Erised so that only somebody who wanted to get the Stone but not use it would be able to retrieve it.]]
* Covenant's white gold ring, which grants power over [[EntropyAndChaosMagic wild magic]] in ''Literature/TheChroniclesOfThomasCovenant'' has fairly finicky requirements - it only works in the hands of its rightful wielder, which is to say, Covenant himself or anyone he ''voluntarily'' gives it to. That voluntarily is important - if the ring is taken by force, given under coercion, or Covenant is possessed or otherwise ensorcelled into giving it away, it'll still have ''some'' power, but nowhere near its full potential. As [[BigBad Lord Foul]] needs every drop he can squeeze out of it to [[OmnicidalManiac destroy the Land]], this qualifier represents a significant obstacle in his schemes. ArcVillain [[EvilSorcerer Kasreyn]] from the second trilogy is more willing to push things; for him, the ring ''itself'' is what matters[[note]]Kasreyn has to insert a "flaw" in the form of a CurseEscapeClause into every spell he casts; the ring, being an alloy and the vector of a chaotic, destructive power, is inherently flawed; if Kasreyn used it as the focus of his spells, it would satisfy the requirement and allow him "to create perfect works without fear"[[/note]]; he doesn't care about getting its full power, and WordOfGod indicates that the only reason he didn't try to just chop if off Covenant's hand was fear that it might blow up or something if he did that.

[[folder:Live-Action TV]]
* ''Series/BuffyTheVampireSlayer'':
** Season 5 features a big hammer which can only be wielded by someone of near-godlike (or Slayer) strength.
** Season 7 introduces a custom stake-ended scythe that "feels right" in the hands of the Slayer. Faith wields it just as well as Buffy. [[spoiler: And by the end of the season a whole slew more girls would find it just as "right."]]
* ''Franchise/StargateVerse'':
** Some Ancient technology (most famously the [[CoolStarship Puddle Jumpers]]) requires a genetic marker (quickly dubbed the Ancient Technology Activation [ATA] gene) to activate. This renders it inaccessible to most humans in the galaxy since the gene is recessive and tends to get bred out of smaller populations. Earth's is big enough to maintain it, and the SGC eventually developed a gene therapy to add the gene to their personnel.
** Much [[Series/StargateSG1 Goa'uld]] technology requires bloodborne [[{{Unobtainium}} naquadah]] to activate, including the hand device and healing device. The most common way to get this is by hosting a Goa'uld, hence why Samantha Carter, who briefly carried a [[LaResistance Tok'ra]] in "In the Line of Duty", can use them.
* ''Series/{{Charmed}}'':
** The Charmed Ones' [[SpellBook Book of Shadows]] would only let good beings or mortals touch it and it would [[SelfGuardingPhlebotinum shield itself]] from Demons and the like. Similarly, The Grimoire, being an ancient and demonic tome, would only let demons and the like touch it and [[SelfGuardingPhlebotinum wouldn't let anyone good touch it]] as it was the EvilCounterpart to the sisters' magic book.
** In season 2 an evil witch is released from a magical sleep and goes out seeking her wand. If she were to obtain it she would be nigh impossible to vanquish. The only way to destroy her would be to use her wand against her, but the only person capable of wielding it would be someone who was the [[MagicalSeventhSon seventh son of a seventh son]].
** In Season 8 Hippolyta's Belt would only let a morally good woman wear it or else it exploded.
* In the ''Series/DoctorWho'' episode "[[Recap/DoctorWhoS33E2DinosaursOnASpaceship Dinosaurs on a Spaceship]]", the controls of the alien spaceship only respond to two pilots who are genetically linked. (How lucky that Rory's dad got dragged along on this adventure...)

[[folder:Tabletop Games]]
* In ''TabletopGame/{{Fringeworthy}}'', only a tiny percentage of the human race has the innate ability to use the Fringepaths without dying.
* In ''TabletopGame/Warhammer40000'', [[TheAlliance Tau]] vehicles apparently use a genescanning system to prevent hijacking, as seen when an Imperial commando tried to steal a battlesuit and got fried for it.
* ''TabletopGame/DungeonsAndDragons'':
** Spell scrolls can usually only be activated by characters who can also access the spell through their class spell list (e.g. only a wizard or sorcerer can use a scroll of ''{{magic missile|Storm}}'', only a cleric or druid can use one of ''[[DeathFromAbove flame strike]]'', et cetera). This restriction can be overcome with a Use Magic Device check. Use Magic Device also lets you overcome [[http://www.d20srd.org/srd/skills/useMagicDevice.htm several other restrictions]], most of which fall under LevelLockedLoot.
** {{Downplayed|Trope}} example: The Holy Avenger is a powerful magic longsword that only allows Paladins to access all of its abilities. Subverted in that any character with the right training can trick it into believing that they're a Paladin.
** Sanctified and corrupt spells (from the 3E supplements ''Book of Exalted Deeds'' and ''Book of Vile Darkness'', respectively) require the caster to be of a class that prepares spells and be of respectively good or evil CharacterAlignment.
** Many magical items have prerequisites such as being evil or worshiping a specific deity; however, they'll usually have a reduced magical effect for those that don't meet the prerequisite or that actively harm opposition instead of acting non-magical.
** [[EmpathicWeapon intelligent weapons]] usually have their own special purpose and/or limitation, so unless the wielder serves the same cause, the choices are few: lack of cooperation, constant wrestling of the wills or bargaining. It may demand encrustation and luxury scabbard or "I'll help you to beat that dragon, but then we'll have a ''big'' undead-chopping foray."

[[folder:Video Games]]
* [=NEXTs=] in ''VideoGame/ArmoredCore'', which can only be piloted by people with some special type of psyche. Ill-defined, but still an example.
* ''Franchise/TheElderScrolls'':
** In ''[[VideoGame/TheElderScrollsIIIMorrowind Morrowind]]'', you must be wearing [[spoiler: Wraithguard]] in order to handle [[spoiler: Keening and Sunder]] without dying instantly. And in order to even ''wear'' [[spoiler: Wraithguard]], you must [[spoiler: sacrifice a large portion of your health, ''permanently.'' If acquired the "standard" way, through Vivec, he will take you "outside of time and space" so that it doesn't harm you]].
** ''[[VideoGame/TheElderScrollsIVOblivion Oblivion]]'':
*** The player can't wear the [[OnlyTheChosenMayWield Amulet of Kings]]; the clasp refuses to close. An [[Literature/TheElderScrollsInUniverseBooks in-game book]], ''[[http://www.uesp.net/wiki/Lore:The_Amulet_of_Kings The Amulet of Kings]]'', explains that it can only be worn by those who have "Dragon Blood" in their veins. This was initially unclear in meaning, but with the release of ''[[VideoGame/TheElderScrollsVSkyrim Skyrim]]'' it's evident that it refers to the Dovahkiin (Dragonborn), humanoids with the souls of dragons, of whom the Septim Dynasty is one line.
*** The Divine Crusader equipment set in ''Knights of the Nine''. To use it, you need to go on a long, annoying pilgrimage, and if your Infamy is raised to anything above 1 after you have obtained it, then you must go on said pilgrimage again.
* The Apple of Eden in ''Franchise/AssassinsCreed'' can only be used by descendants of the first civilization.
* Various items in the ''VideoGame/NeverwinterNights'' series are keyed to a particular race, class, and/or alignment. For example, [[VideoGame/NeverwinterNights2 the sequel's]] Hammer of Ironfist can only be wielded by dwarves, and many {{prestige class}}es have unique armors. A successful Use Magic Device check will override these restrictions, however.
** {{Inverted|Trope}} with the plot-relevant Ceremonial Sword of Neverwinter and the Silver Sword of Gith, which are classified as "universal swords" to allow even characters that lack sword proficiency to wield them. The downside is that this typing also means that none of your weapon specialization feats (e.g. Weapon Focus) work on them.
* The MacGuffin of ''VideoGame/{{Skullgirls}}'', the Skull Heart, can only be used by those who are absolutely pure of heart, or else they will become the Skullgirl themselves. [[spoiler: Parasoul's mother wanted to end a war, and the war ended, alright...[[JackassGenie by turning her into the Skullgirl]] and forcing everyone to unite against her. Similarly, Bloody Marie presumably wished for her freedom from enslavement by the mob, only to become [[HeWhoFightsMonsters as ruthless as the mobsters she kills.]]]]
* In the ''VideoGame/PaperMarioTheThousandYearDoor'' intro, the chest containing the magical map that the merchant gives Peach says that only someone pure of heart can open it. Peach was able to open it. Later, it is revealed that [[spoiler: The merchant was actually Beldam in disguise; who did so because she was trying to unseal the Shadow Queen, and needed the Crystal Stars to do so since the Crystal Stars are needed to open the Thousand Year Door, which is where the Shadow Queen is sealed. The magical map is what allows you to find them.]]
* In ''VideoGame/TheLegendOfZeldaOcarinaOfTime'', Link could only wield the Master Sword when he is an adult, so upon gaining it he was put into a sleep for seven years.
* Inverted in ''VideoGame/SeveranceBladeOfDarkness''. The [[InfinityPlusOneSword macguffin]] required to defeat the final boss is the only weapon that ''isn't'' restricted by class.
* ''Franchise/{{Halo}}'': There's a reason 343 Guilty Spark keeps addressing [[PlayerCharacter Master Chief Petty Officer John-117]] as "Reclaimer" in ''VideoGame/HaloCombatEvolved''. The [[{{Precursors}} Forerunners]] keyed some of the technology they left behind to only be usable by humans before they activated the Halo rings to destroy the Flood and themselves. This is to the point where in ''VideoGame/Halo3'' the Prophet of Truth is shown trying to physically force Sergeant Johnson to remotely activate the remaining Halo rings.
-->'''[=SgtMaj=]. Johnson:''' ''[while being slammed into a control panel by a Brute]'' What's the matter, can't start your own party?
:: In fact, it's later received that even among humans, only ''some'' have the ability to access Forerunner tech; namely those descended from specific prehistoric humans whom the Forerunners had given inheritable ''geas'' to.
* In ''VideoGame/{{Xenogears}}'', the "Fatima Jasper" is said to be the key to the treasure of the Fatima dynasty, the [[LostTechnology Omnigear]] [[HumongousMecha Andvari]]. Rumors imply that the Fatima Jasper is a precious stone, to hide the fact that [[spoiler:it actually refers to the distinctive blue eyes (or more specifically the retinal pattern) of the Fatima royal family, needed to unlock the retinal scanners protecting the Omnigear.]] [[spoiler:This also serves as an opportunity for the story to reveal that Bartholomew Fatima's companion Sigurd is his [[LongLostRelative illegitimate half-brother]], when his eye ends up being needed to help unlock one of the doors.]]

[[folder:Web Original]]
* In ''WebVideo/TalesFromMyDDCampaign'', the evil [[FishPeople Kua-Toa]] have found out how to power an alchemical InvisibiltyCloak using their skin secretions. This not only lets them produce the cloaks for 1/100th of what such a powerful item should cost, but also makes them impossible to steal, as only a living Kua Toa can produce the chemicals that power the thing.

[[folder:Western Animation]]
* ''WesternAnimation/RegularShow'' has the Sandwich of Death, which is deadly unless you eat it the right way: by wearing a mullet and cut-off shorts.
* The Elements of Harmony in ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' require wielders who embody their respective virtues and work together as a team. Otherwise, as shown in for example "[[Recap/MyLittlePonyFriendshipIsMagicS2E2TheReturnOfHarmonyPart2 The Return of Harmony]]" when five of the [[FanNickname Mane Six]] are "discorded", they simply don't work.
* ''WesternAnimation/StevenUniverse'': Gem technology (most obviously [[PortalNetwork Warp Pads]]) can only be activated by gems and lays dormant otherwise. It's unclear if this is a deliberate feature or [[OperatorIncompatibility accidental]], but the result is [[SufficientlyAdvancedBambooTechnology ancient-looking high technology]] sitting around the Earth unguarded for thousands of years without any human reverse-engineering. The only exceptions are the [[MatterReplicator replicator wand]] in "Onion Trade" and the Warp Whistle that lets humans active Warp Pads in "House Guest".
* An {{inversion}} in ''WesternAnimation/TheBatman''. When Batman goes up against Gearhead, who likes to use his {{nanomachines}} to hijack vehicles, he is forced off the road and the Batmobile is totaled. Bruce reverse-engineers one of Gearhead's nanite launchers (recovered from an ArmedBlag he pulled) in order to make his new Batmobile Gearhead-proof: it electrocutes him when he tries to take over its systems.