It is a fact that no safe can ever be impregnable. Even a meter thick titanium box could be cut through eventually. Security measures are designed with the intent of making any attempted break in so time consuming and recognizable that the thieves will be apprehended before they can succeed. So long as the thieves were somehow able to secure themselves sufficient time and privacy however, there are ways of penetrating just about any physical security.

But while you can't make it impossible for thieves to get in, you can make it impossible to get anything out intact if they don't use the proper access method. So long as it's more important that the contents stay out of the wrong hands than in one piece, you setup a failsafe that will destroy the contents before an attempted break in can be completed. The technique also has the advantage of not requiring any staff to check on the security regularly, and so is good for security that will be unattended for long periods.

This is typically used to protect information rather than unique objects, as it's easier to have a backup copy so that the loss of any single copy doesn't mean it's lost forever. However it can also be found used with unique items that would be dangerous in the wrong hands, under the logic that it's better for no-one to have it than the wrong people.

Compare SelfDestructMechanism, which is typically deliberately triggered by the owner of vehicles, buildings and bases, and ThisPageWillSelfDestruct where messages self destruct on a timer to avoid falling into the wrong hands, rather than being triggered by an attempted theft.

See also BoobyTrap, which the intent is to destroy the thief more than the loot. When this technique is used by a person to kill themselves to avoid torture/giving up secrets, that's CyanidePill. If said person is wired to kill themselves involuntarily before they divulge important data, it's InvoluntarySuicideMechanism instead.
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!!Examples

[[foldercontrol]]

[[folder:Anime and Manga]]
* ''Manga/DeathNote'': Light goes to great lengths to protect the Death Note. Not only is it hidden in his locked bedroom in a secret panel of his desk drawer, but opening the panel without first deactivating the failsafe will incinerate the notebook before it can be found. After all, if someone else takes it he's unlikely to get it back, and it links him to hundreds of murders.
* ''Anime/LupinIIITheWomanCalledFujikoMine'', in the sixth episode, [[Recap/LupinIIIS4E6 "Prison of Love"]]: The pendant Fujiko steals from Oscar is locked by a code ([[spoiler:Ze-Ni-Ga-Ta]]), and the wrong code will destroy the other half of the thesis.
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[[folder:Comic Books]]
* Franchise/{{Batman}} has this on his [[CoolCar Batmobile]]. He has a number of deterrents to prevent crooks from jacking the Batmobile, up to five levels. The fifth level being detonating the Batmobile. Batman nearly became a victim of this in the final part of the ''KnightFall'' storyline, ''[=KnightsEnd=]'' when he attempts to use the Batmobile to hunt down the rouge "Az-Bats" Jean-Paul Valley and it ends up blowing up on him. The incident causes {{Nightwing}} to go on a RoaringRampageOfRevenge on Jean-Paul, but Robin later finds out Bats is safe. Turns out he realized that Valley did the same thing he would have - just not that deadly.
* ''Comicbook/JudgeDredd'' has a variant of this in the [[SwissArmyGun Lawgiver pistol]]. The weapon has a built-in identification device that scans the user's fingerprints for the right ID. If the person's profile doesn't match the DNA for the Lawgiver, the weapon triggers a [[StuffBlowingUp built-in explosive device]] that severs the entire weapon [[AnArmAndALeg and the limb of the wrong person attempting to use it]].
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[[folder:Film]]
* The Holy Grail in ''Film/IndianaJonesAndTheLastCrusade'' is protected by many layers of secrets, guards and traps. The final resort, however, is that the Grail can never pass beyond "The Great Seal". Doing so results in the entire place self destructing and the Grail being lost forever.
* ''Film/JamesBond''
** ''Film/FromRussiaWithLove'': Bond's attache case has numerous built-in gadgets including a magnetically attached tear-gas canister stored inside. Opening the case without first rotating the clasps triggers the grenade and gives any would-be-snoop a face full of the gas. [[spoiler:This turns out to be just the edge Bond needs when held at gunpoint by Red Gran, whose greed Bond uses to trick him into opening the case.]]
** ''Film/{{Goldfinger}}'': As a shout out, it's implied that Bond's case still has similar defensive measures in the following film, even though they're never explicitly mentioned. After being captured, he talks to one of Goldfinger's henchwomen on the plane.
-->'''Bond:''' Did any of my luggage survive with me? And my attache case?
-->'''Mei-Lei:''' Black attache case damaged when examined. So sorry.
-->'''Bond:''' Apologies quite unnecessary.
** ''Film/ForYourEyesOnly'': Bond's car has an anti-theft measure which blows it up if it's broken into. Considering all the high tech gear in every car Bond drives, it's probably more to protect those things than the car itself.
* In ''TheItalianJob'' the villain's big safe has a piece of glass inside the door; if the glass breaks - and drilling into the safe will almost definitely achieve this - the lock's tumblers will be unable to rotate properly and the safe will be permanently sealed. Doesn't actually destroy the gold inside, but the safe is ''huge''; if you have the tools to rip the door off, doing so would have been your first option, not second.
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[[folder:Literature]]
* In ''TheDaVinciCode'', the cryptex protects its contents with a combination lock. Attempting to force the cryptex open will break the vial of vinegar inside, which would dissolve the papyrus along with its message before it could be read. As a result, only the right password will grant access to the message.
** This is demonstrably a case of ArtisticLicenseChemistry, though; vinegar isn't a powerful enough solvent to dissolve papyrus, which is fairly sturdy stuff.
* The MatthewReilly short story ''Altitude Rush'' ([[http://www.matthewreilly.com/resources Available in pdf on his website]]) has documents protected by a self destructing case that will release hydrofloric acid on the papers unless properly accessed. The case also has an altitude sensor that will trigger the self destruct if it goes above 1000 feet or below 10 feet, necessitating the thieves to execute a frantic escape across the NY skyline.
* In ''Literature/TheDresdenFiles'' the stolen [[PublicDomainArtifact Shroud of Turin]] is kept like this, with a remote to deactivate the security. In this case it's a precaution against the seller being subjected to YouHaveOutlivedYourUsefulness after handing it over.
* ''Literature/TheDarkIsRising'' series novel ''The Dark is Rising''. The Book of Gramarye is kept in a grandfather clock with a magical security mechanism. If the Book touches the clock's pendulum while it's being removed or returned, it is totally destroyed. The same thing will occur if an Old One tries to remove the book and they're not touching a specific human being[[note]]who, unlike the Old Ones, could be killed by the Light if necessary to stop the book from being removed[[/note]] at the time.
* In the Creator/TomClancy novel ''[[Literature/JackRyan The Cardinal Of The Kremlin]]'', the information from the title spy would be typed up in the American Embassy on flash paper and inserted into a container which would ignite if anyone tried to mess with it. It was then transported by diplomatic courier[[note]]specifically, not in the diplomatic pouch, but carried personally by the courier to prevent it from being knocked around, as it also had an accelerometer to activate the incendiary device[[/note]] to CIA headquarters, where it was disarmed in the office of the CIA Director.
** It's mentioned a couple of times that with the case actually in the courier's breast pocket (it looks like a cigarette case), if it went off, the courier would likely be set on fire.
* Creator/RobertAHeinlein's ''Literature/TheNumberOfTheBeast''. Computer software expert Deety mentions that if anyone except herself attempts to access her college computer account it would show them her "clean" financial records while secretly deleting the "dirty" copy.
* In Jeffery Kooistra's ''Dykstra's War'', the eponymous Dykstra receives a thumbprint-coded package that, if accessed by the wrong person, will explode with sufficient force to take out ''the whole building''. Clearly one wants to be ''very careful'' about checking the address labels.
* In HarryHarrison's ''The Ethical Engineer'' (second book of the {{Literature/Deathworld}} series), Jason crash-lands on a LostColony where remains of technology are with a religious-like fervor by various clans/cities. One of them builds primitive cars and have booby-trapped the engines should someone attempt to open and reverse-engineer them (or repair them - they make the cars so that they break after a few months). Jason is trying to break the monopoly and allow progress, currently working for the group making petroleum (to run said cars). He tries to make an impression by making repairs to one car. One of the traps (poison gas canisters) is triggered by attempting to remove the screws holding the cover. Jason figures out that the screws are deliberately threaded the wrong way (i.e. you have to turn clockwise instead of counterclockwise). Attempting to turn counterclockwise tightens them and smashes the canisters. He then defeats another trigger mechanism by using melting ice to slowly lower the engine from the housing.
* In ''Literature/CarterBeatsTheDevil'', the plans for the prototype [[spoiler: television]] are in a safe set to spill acid on the plans if the wrong combination is set three times.
* In ''Literature/AtlasShrugged'', John Galt protects the shed containing his {{utopia}}'s power source (a PerpetualMotionMachine) and his secret laboratory in his obscure flat in New York City in such a way that anyone trying to break into the rooms or force the locks will cause everything in the rooms to disintegrate into dust by the time they get the door open. How? Who is John Galt?
* An anti-handling device kills some MI5 safecrackers in the ''Literature/BernardSamsonSeries''. According to the mission post-mortem, the confines of the safe turned the document destruction device into an accidental bomb. However there's also the possibility that it was a BoobyTrap meant to kill Bernard Samson.
* Mentioned in the ''ArtemisFowl'' series. After pulling off a heist for a painting, Artemis checks for pyrophoric/explosive chemicals in the storage tube, in case the person he's stealing from is particularly spiteful.
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[[folder:Live Action TV]]
* In Season 4 of ''BurnNotice'', an important MacGuffin is buried in a graveyard in an airtight container, which also contains highly reactive chemicals that would explode when exposed to the air. [[spoiler: Filling the grave with machine oil allows them to get inside safely.]]
* In the New Year's Day 2012 ''Series/{{Sherlock}}'' episode "A Scandal in Belgravia," Irene Adler's phone, containing lots of politically-sensitive data, contains miniature explosives that will destroy it if anyone attempts to physically remove the hard drive, or enters the wrong passcode too many times.
* The pilot episode for the show ''WhiteCollar'' features this in the beginning. Peter and his team are attempting to crack open a safe that has a counterfeiter's information in it. If they can get into the safe, they'll have enough evidence to arrest the counterfeiter. Unfortunately, as soon as they crack the safe, an explosive charge destroys everything inside, showing Peter and his men with confetti.
* In ''Series/{{Farscape}}'', the ancient Luxan ship is equipped with a self-destructing security mechanism powerful enough to blow up the ship it's parked in. Thankfully, it also loops through a vocal message explaining how to defuse it: It requires [[spoiler:any one of three keys only a Luxan is supposed to have; Qualta blades are one of them]].
* In ''Series/LaFemmeNikita'', some sensitive information is stored on shadow drives -- hard drives which must be read backwards, or they will erase their data.
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[[folder:Tabletop RPG]]
* ''TabletopGame/{{Shadowrun}}''.
** Matrix software
*** The Scramble IC program is often used to protect computer datastores with valuable information. If a decker tries to break through the Scramble and fails, it will overwrite the stored information with random characters, rendering it worthless.
*** A decker tries to disarm a Data Bomb protecting a file and fails. If the Data Bomb was programmed to do so, it will erase the file it was protecting.
* ''DungeonsAndDragons''
** Basic D&D module [=CM1=] ''Test of the Warlords'', Encounter 1 "The Ruins of Alinor". The {{PC}}s can find a golden box that radiates magic. If they smash or pry open the box, its contents burn up in a flash. If it is unlocked normally or its lock is picked by a thief, they will find two magical scrolls and a diary.
** In early editions the Explosive Runes spell could be used like this. The caster would cast the spell on the object to be protected. If anyone read the runes, they would explode and destroy the object and whatever it contained.
** Occurs twice in the adventure T1-4 ''{{TapletopGame/Temple of Elemental Evil}}''.
*** In one room there's a chest with a chlorine gas trap that functions no matter how the {{PC}}s try to disarm it. When they open the chest they find what appears to be spell books and a magical scroll that have been partially dissolved by the gas. In fact they were covered with gibberish and therefore worthless - it was just a trick to make the {{PC}}s think they had lost a chance to gain valuable items.
*** Senshock, one of the demon lord Iuz's minions, knows some of his master's secrets. If anyone (such as a group of {{PC}}s) uses Charm or any other MindControl effect to make him reveal these secrets, Senshock will suddenly and mysteriously die, slain by luz himself.
** Module [=DA1=] ''Adventures in Blackmoor''. All of the Iron Duke's agents in the Comeback Inn (as well as the Warden in the Prison Out Of Time) have a special Geas placed on them. If anyone uses torture or magic to try to force them to tell about the plane to kidnap King Uther, the Geas will kill them.
* ''Hot Chicks'' RPG. Escorts from the Arcturus Escort Corporation have built-in cybernetic data recorders to capture their clients' secrets. If anyone tries to tamper with an escort's recorder it overloads, destroying the stored data and killing the escort.
[[/folder]]

[[folder:Video Games]]
* In the videogame ''{{Uplink}}'' one of the security measures you can purchase for your gateway is a self destruct mechanism as a last resort if the Feds are closing in on you. You lose all the hardware, but get to keep your reputation and avoid being disavowed (ie, gameover).
* In Creator/{{Infocom}}'s ''VideoGame/{{Enchanter}}'' there's an mechanical egg with a scroll inside. No matter how you open it, the egg shreds the scroll so it's unusable. You later get a spell that allows you to reconstitute the scroll and learn the spell on it.
* In ''SystemShock 2'', if you [[CriticalFailure trigger an ICE node]] when hacking open a security crate, it sets off a built-in explosive charge, destroying the crate and its contents (and on any difficulty higher than Easy, probably kills you in the process).
* {{Downplayed}} in ''VideoGame/TheRiddleOfMasterLu'': When Ripley finally grabs the MacGuffin from the tomb of the first emperor of China, he finds out that Master Lu had some final mechanism designed to keep it from falling to the wrong hands whose secret Ripley didn't uncover, and which causes liquid mercury to start flooding the place. It happens so slowly you can just walk away, so it should be useless, but it just happens that [[spoiler: the game's last villain shows up to slow Ripley's escape and ends up taking the MacGuffin with him as he gets flooded by the mercury, effectively helping the mechanism do what it was supposed to do.]]
[[/folder]]

[[folder:Western Animation]]
* ''WesternAnimation/StarTrekTheAnimatedSeries'' episode "The Slaver Weapon". The title device had an {{AI}} computer programmed to make sure its user was a Slaver authorized to operate it. When the Kzinti that found it asked ignorant questions of it, it assumed that it had captured by its master's enemies and tricked them into activating a self-destruct setting which destroyed it...and them.
** This might be more accurately described as a CyanidePill, if the AI was truly making a decision rather than simply executing a built-in program. The episode doesn't give enough information to tell either way.
* In ''WesternAnimation/TeenageMutantNinjaTurtles2012'', Donatello has a failsafe on the T-Phone (their personal communicators and cell phone service), just in case. If anyone yells "T-Phone, Self-destruct", the tech inside will blow out, making getting any information off the phone impossible.
[[/folder]]

[[folder:Real Life]]
* U.S. top-secret documents are carried in briefcases that are booby-trapped with oxidizer bricks, which incinerate the documents if the case is opened without the disarm key inserted.
* WW2 Uboat codebooks were printed on paper that would dissolve in water. Not only did this make the codebook easy to destroy, even if the crew were killed before they could do so, an attack on the sub would be very likely to cause the codebooks' destruction anyway. That didn't stop the Allies from seizing ''[[CrowningMomentOfAwesome half a dozen]]'' of them.
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