->"No one but me can keep this heap running."
-->-- '''Nancy Callahan''', from the ''SinCity'' story "That Yellow Bastard."

Sometimes the owner or driver of a vehicle has [[MachineEmpathy a certain connection]] to their vehicle (be it a car or spaceship etc.) and a way to demonstrate that bond is to make the operator the only individual who can make it run. In the hands of someone else it will fail to start or come to a stop after a few seconds without the gentle touch of the person who knows the special trick to starting the engine or all the little adjustments you have to make.

It tends to happen with either the very best or very worst of cars. TheAllegedCar is so rotten through that it needs someone with great knowledge of all its faults to keep it going (and sometimes overlaps with PercussiveMaintenance when only the owner knows the sweet spot). The AceCustom CoolCar can also be full of complex gadgets that you need to keep track of. Or maybe it's just so cool it only deserves the really attentive owner.

Because [[AutomatonHorses horses are just another kind of vehicle]], a MoodyMount may respond this way to a FluffyTamer.

Related is EmpathicWeapon, which typically will ''only'' work for its owner. (Though it is not unknown for a character using this trope to talk as if that trope was in play.) A BlackBox is when the "I" in the equation is not present, and the people involved try to bulldoze their way into forcing the something to run, with unpredictable results. MagicPoweredPseudoScience is when the maker is the [[AWizardDidIt wizard who did it.]]
!! Examples:


[[folder: Anime & Manga]]
* Eureka of ''{{Eureka 7}}'' is [[spoiler:at first]] the only one who can pilot the Nirvash [=TypeZERO=].
* Simon is the only one who can pilot the [[TengenToppaGurrenLagann Lagann]].
** This seems to have more to do with the fact that he's the only one with a [[CoolKey core drill]], not counting [[spoiler:Lord Genome]], and they might not be interchangeable anyway.
** In addition to the key, the Lagann is attuned to Simon because of his latent Spiral power. Other characters develop Spiral power over time, [[spoiler: and eventually get their own Lagann-type mechs in the end]], so it's likely that someone else could pilot it if Simon gave them the core drill. The one time he tries, Kamina rebuffs him because he recognises that Simon is better suited to it.
* Kaneda's bike in ''Manga/{{Akira}}'' is tricked up enough that he's the only one who can keep it going. When Tetsuo tries to steal it, it ends up winding down and landing him in trouble.
* Hayato from ''Anime/FutureGPXCyberFormula'' is the only person who can drive Asurada, since the car has an AI system with a unique security feature.
* Explained as one of the problems with the [[Anime/MobileSuitZetaGundam Zeta Gundam]] by the time ''Anime/MobileSuitGundamZZ'' rolls around. By the end of its service life, the Zeta Gundam was so customized and tailored to Kamille Bidan's specs that while Judau and later Roux are able to pilot it with some effort, they can only as much as it's base specs allow. They can't access the biosensor to let it do the crazy things Kamille made it do in Zeta because only his mind could trigger it, even though Judau was an even stronger Newtype than Kamille.
** In ''Anime/MobileSuitGundamSeed'', Kira is told to place a lock on the Strike's systems that only he can open when they dock at an Alliance base. The reason for this is that the Alliance is [[FantasticRacism heavily racist against Coordinators]], and having that lock there gives Kira a bargaining chip to protect himself.
*** That was just to prevent the jerks from tampering with the Strike's systems. He had re-configured the mech's OS in order to get it to operate properly when he initially [[FallingIntoTheCockpit Fell Into The Cockpit]]. Being a Coordinator, he put in a system that was too complex for unaltered humans to use, so he was the only person on the base who ''could'' operate the Strike.
** ''Anime/MobileSuitGundamUnicorn'': The Unicorn Gundam has been hard-coded so that only Banagher Links can pilot it, which is the primary reason the various factions keep him around rather than just stealing the Gundam for themselves.
* In GaoGaiGar, the titullar mecha could only be piloted by Guy. Originally, anyway.
** It's likely any G stone powered being could use it. It's just that Guy was one of only two around and the other was kid that was too young to use it properly. Gaofaigar on the other hand was fueled by his evoluder powers which were unique to him (Mikoto's were different) which meant only he could use it.
* In ''Anime/CodeGeass'', Lelouch's second season mecha the Shinkirou features a scattering energy cannon and the strongest BeehiveBarrier in existence. However, it takes an exceptionally smart and quick-thinking pilot in order to draw out their full potential; in the hands of anyone but Lelouch, it's still high tech but not nearly as powerful.

[[folder: Comic Books]]
* Archie in ArchieComics sometimes plays this trope straight, sometimes pokes fun at it. For instance, in one comic, Arch said he couldn't lend the car out to Betty because he was the only one who knew how to keep her running. Oh course, when the car ''did'' break down and he couldn't figure out what the problem was, [[WrenchWench guess who figures out how to fix the jalopy...]]
* Nancy Callahan of the ''SinCity'' story "That Yellow Bastard" has a car so old and in such bad shape that it will stall out on anybody who tries to drive it, except for her. When her kidnapper, the title character, can't get it working, he has to take her to the Roarks' infamous farm on foot, giving Hartigan time to catch up to them and save her.
* In ''SuicideSquad'', Briscoe claimed to be the only one capable of piloting the team's helicopter Sheba. Given how possessive he was about Sheba, and that she seemed to respond to the sound of his voice, no one was ever quite game enough to test his claim.
* DependingOnTheWriter, the Batmobile sometimes has anti-theft features specifically designed so that no one except Franchise/{{Batman}} can start it. An interesting incident happened during the tail end of ''[[ComicBook/{{Knightfall}} Knights End]]'': after [=AzBats=] drops into the river, Batman races to the Batmobile (which somehow followed them) and tries to get in. Jean-Paul changed the locks, but Bruce overrode them. He hops in, starts it up... and the Batmobile ''[[MadeOfExplodium explodes]]''. He survives and tells the Tim Drake Robin that he would have done the same thing for an anti-theft deterrent, but not like ''that''.

[[folder:Film-Live Action]]
* Biff in ''Film/BackToTheFuture: Part II'' had a very sweet ride which only he could start the ignition of (to the bemusement of his mechanic). After the {{Exposition}} of this in the scene with the mechanic, it's used as a sort of time travel TrustPassword by his future self who had come to give him [[TimelineAlteringMacGuffin Gray's Sports Almanac]].
** It's also notable that the [=DeLorean=]'s starter motor never stalls out for Doc, only for Marty.
* In ''Film/TwoThousandTwelve'', the car that's used to escape from the plane would only start from Yuri's voice recognition.
* ''Film/TheTransporter'' has his cars equipped with a keypad that requires a correct code to turn the key. The second film starts with a bunch of punks trying to steal his car only to find out that it won't start without the code. And Frank won't give them the code. Then they make the mistake of trying to [[TooDumbToLive beat it out of him]].

* This is kind of the point of ''Literature/AtlasShrugged''.
* When [[spoiler:Mr Gilbreth]] dies at the end of Literature/CheaperByTheDozen the family sells the car for scraps, seeing how he was the only one able to start it.
* In ''Corner of a Round Planet'' this is subverted, but not averted. All Auggies have a custom-built rig that responds to their particular brainwaves. The rigs lose significant efficacy when the wrong driver attempts to use them.
* In [[StarWarsExpandedUniverse Shadows of the Empire]], the ''Millennium Falcon'' is described as this, with Han Solo and Chewbacca having overcustomized the freighter to the point where even Lando can't do proper maintenance on it because the circuitry is such a mess. Interestingly, it fits ''both'' sides of the trope; it's [[TheAllegedCar The Alleged Spaceship]] to [[WhatAPieceOfJunk look at it]], but [[AceCustom one of the best ships in the galaxy]] with Han Solo flying it.
* Rangers' horses in RangersApprentice can only be ridden if rider asks for permission in specific words mounting for the first time. Anyone who didn't gets a free lesson in doing summersaults.

[[folder: Live Action TV]]
* [[KnightRider Michael Knight]] gave the explanation that the car's onboard computer could read his fingerprints - it's more plausible than the car having AI.
* Implied in the old ''Series/DoctorWho'' episode "The Pyramids of Mars" that only The Doctor can operate his TARDIS. He may have been lying, though...
** TheMaster sure had no trouble using it, though it may be that only a Time Lord can use it and the Doc is ''usually'' the only one around.
** Steven and Leela have both managed to pilot it.
** So has River Song - though it's been both denied and implied (in that order) that the Doctor taught her to drive it.
*** Ultimately denied: she was taught by the TARDIS itself.
** In the 2010 Christmas special ''A Christmas Carol''; this time it's not the TARDIS in question but, a device that will save the lives of people aboard an out-of-control shuttle craft in a cloud belt storm. Although it's not a vehicle, it's a machine that controls a planet's clouds. Too bad the only one who can work the controls is a bitter old sod who couldn't give two dumps about what happens to the people aboard. The Doctor gets so fed up with the man's heartless personality that he goes back in time to directly alter that man's past so he doesn't grow up into such a monster. Unfortunately, the Doctor's meddling works ''too'' well and [[spoiler: the machine no longer recognizes the man because his personality has become remarkably different.]]
* A partial example occurs in ''{{Lexx}}'': Only one person has the "key" to the titular ship (a small EnergyBeing that embeds itself on the recipient's hand) at any given time and it can only be passed on by the original holder dying or being "brought to the height of sexual ecstasy". Severing the owner's hand seems to work too.
* Played for laughs on an episode of ''{{Cheers}}''. The gang takes a road trip in Cliff's car and crash. Getting the car back on the road requires some things Cliff didn't tell them.
-->'''Sam''':Cliff, I'm turning the key, but nothing's happening.
-->'''Cliff''':That's because I've got it rigged up with a Cliff Clavin Anti-Theft System. What I do is I turn the wheel all the way to the left.
-->(Sam turns the wheel.)
-->'''Sam''':Got it.
-->'''Cliff''':And then I turn the key as hard as I can.
-->(Sam turns the key.)
-->'''Sam''':Oh dear. Cliff, I just broke off the key in the ignition.
-->'''Cliff''':I said as hard as ''I'' can, Sammy!
* ''Series/StargateSG1'' and ''Series/StargateAtlantis'', and their Ancient technology, which can only be used by those possessing the Ancient gene.

[[folder: Tabletop Games]]
* The [[OurOrksAreDifferent Orks]] of ''TabletopGame/{{Warhammer 40000}}'' have a latent psychic field that allows their vehicles to function in bizarre ways because [[ClapYourHandsIfYouBelieve they believe they can]] ([[FunetikAksent Red wunz go fasta]], planes keep flying until the pilot is informed they ran out of fuel a while ago, etc). So when a non-Ork uses one, it tends not to work.
** [[DependingOnTheWriter Depends on the writer]] though, as Literature/CiaphasCain ('''HERO OF THE IMPERIUM!''') at one point had a sizeable fleet of commandeered ork vehicles for his ragtag refugee army. Granted, he had a techpriest along (who was fascinated by them, as they shouldn't have worked at all), but most worked without her help.
* In ''TabletopGame/{{Pathfinder}}'', the gunslinger class starts off with a basic gun which only they can use properly, and can therefore only be resold for scrap. This is something of an ObviousRulePatch, since firearms are among the most expensive non-magical items (the ones available as starting weapons should cost 1000 to 2000gp; more money than they should see for at least a couple of levels).

[[folder: Video Games]]
* Quite a far out example, but in ''BreathOfFire II'', your town can be turned into a FloatingContinent that can only be controlled by your father, who has been wired into the technology.
* In ''Franchise/MassEffect'', Joker says something along these lines when asked about piloting the Normandy.
* In ''JadeEmpire'', Kang says the same for the [[GlobalAirship Marvelous Dragonfly.]]
** Both of those expand the trope from just being about clunkers in the hands of someone used to their quirks, to extremely sophisticated devices in the hands of a specialist.
*** And in Kang's case he spends literally every hour of the day making modifications to the Dragonfly (he doesn't sleep). The controls probably change completely from flight to flight.
* The Alteisen from ''VideoGame/SuperRobotWarsOriginalGeneration'' is an impractical junk heap of a HumongousMecha that's very hard to handle due to its grossly encumbered frame, unbalanced weight, and ridiculous amount of thrust. Only Kyosuke is stated to be able to handle the machine within the story, thanks to his devil's luck. [[GameplayAndStorySegregation However, in gameplay, there's nothing that's stopping you from switching in any other pilot.]]
** The thing about the Alt, and it's upgrade, is that piloting it is much like gambling. To use it effectively, the pilot has to dash in and hammer the enemy with close-to-mid-range weapons. The pilot can do a lot of damage this way, but it also leaves them wide open enemy retaliation; It's a high-risk-high-reward style of fighting. Kyosuke, being TheGambler, likes to fight that way, and has the skill to pull it off.
** In the mainstream series, on one hand, it's justified with certain pilots always driving certain robot as it would be illiogical to let pilots from different series do. On the other hand, real robots such as Gundam usually plays with this. While UC and [[TurnAGundam Black History]] pilots are interchangeable, unique Gundam series such as ''Wing'', ''X'', and Seed'' are stuck with their respective mechs.
* The third ''VideoGame/DynastyWarriorsGundam'' combines this with MythologyGag. Any Mobile Suit with AttackDrones, [[PsychicPowers psycommu systems]], or is otherwise confirmed to require superhuman or extrasensory abilities to pilot can only be selected by pilots with the Newtype attribute, even when the license to unlock it for everyone other than its signature pilot is obtained.
* In the original ''[[RatchetAndClank Ratchet & Clank]]'', only Clank can start Ratchet's ship at the beginning of the game, since Ratchet is missing crucial components that makes it start. This aspect is almost immediately forgotten, until Clank reminds us of this after the first boss fight.
* [[spoiler: Licia]] from [[DarkSoulsII Dark Souls 2]] says this about a certain rotating door. of course, [[spoiler: she's lying her heart out.]]
* The Last Hydral in VideoGame/TheLastFederation is the only one who can control Hydral technology. Occasionally you'll find a battlefield where another race has managed to switch something on, but it's always berserk and attacking indiscriminately.
[[folder: Western Animation]]
* A large part of the premise of ''MegasXLR'' is that Coop messed around with the mech's interfaces while refurbishing it, to the point that Kiva can no longer make heads or tails of it. Therefore he has to pilot it.
** Note that the mech's interface now consists of a [[CoolCar Plymouth Barracuda]], [[IKnowMortalKombat several different game controllers]], and many, many {{Context Sensitive Button}}s. Even Coop has trouble with it.
* In an episode of the ''TheFlintstones'' where Fred gets himself fired, Mr Slate is forced to get him back after discovering that his handling of his dinocrane has made it so that only he can use it properly. [[FridgeBrilliance Which makes sense, since its an animal that he "tamed"]]

[[folder:Real Life]]
* Certain high end cars, such as Mercedes, tried this particularly those sold in countries prone to carjacking, sometimes offer thumbprint recognition as an ignition lock. Unfortunately, this just makes carjackers cut the driver's thumb off. Some thumbprint recognition devices also make sure the thumb is alive first (i.e. check for temperature and blood flow).
** Additionally, manual gearboxes are not as common in the United States as they were previously. Which makes for excellent theft deterrence.