->'''Batman:''' What would stop you from doing what the [[MirrorUniverse Lord]] Superman did?\\
'''Superman:''' There's always that kryptonite you carry around.\\
-- ''WesternAnimation/JusticeLeague Unlimited''

Your friend reveals that he knows of some weakness that you have, or has a tactic or piece of AppliedPhlebotinum in reserve specifically to take you down; you know, [[CrazyPrepared "just in case"]].

Maybe he has been betrayed before, maybe he doesn't trust [[ProperlyParanoid anyone at all]], or maybe he simply thinks you are too dangerous, might someday [[AGodAmI give in]] to the temptation to abuse your powers, or most benevolently, MindControl is real in this world, and you don't have any immunity to it. Whatever his motives, he's sitting on HiddenSupplies of the necessary items or substances to put you down in an instant if the need arises.

Regardless of why the Betrayal Insurance policy was originally created, it is rare for it to be used.

How ''you'' feel when you find out your friend has a policy out on you will vary. Mostly depending on where the show you're in falls on the SlidingScaleOfIdealismVersusCynicism.

This also occurs when [[FaceHeelTurn the betrayal]] has already happened and one of the betrayed reveals he has something for just this situation.

Compare to KryptoniteRing, where someone personally takes precautions in case he ever goes bad himself.

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!!Examples:

[[foldercontrol]]

[[folder:Anime and Manga]]
* Late in ''Manga/ZettaiKarenChildren'', [[spoiler:Minamoto]] is ordered to always carry [[spoiler:the gun with which he kills Kaoru in the precog's visions]], notably he feels pretty conflicted about it.
* In ''Manga/OnePiece'', [[spoiler: Ivankov allows Crocodile to join in the break-out of Impel Down, because he knows a "terrible weakness" of his that he will expose if Crocodile backstabs them.]]
[[/folder]]

[[folder:Comic Books]]
* In ''Comicbook/{{Runaways}}'', Chase gives Niko a list of LogicBomb questions that will shut their resident robot down if he ever does the FaceHeelTurn that a friendly time traveller warned them about. Given Niko's oft-stated feelings about the possibility of any of her friends betraying the group [[spoiler:again]] no one should be surprised if she has spells thought up for all of her comrades.
* This specific dynamic, Franchise/{{Batman}} holding Kryptonite, appears again and again, especially in the {{DCAU}}.
** In the JLA story-arc "Tower of Babel", it is revealed that Batman has very, very cynical methods set away in case any of the Justice League members go rogue. The plans are stolen and used against them by [[spoiler:Ra's al Ghul]]. The enemy starts by using a sort of third-party Kryptonite Ring against Batman: stealing his parents' bodies from the cemetery. This works to distract the Bat, drives him nearly mad, and leads him to abandon the JLA while searching for the culprit. After it's all said and done, the JLA (who had no idea about the plans) are pissed with Batman and consider throwing him out of the League. His plans are the following:
*** For Superman, there's an altered version of Kryptonite that shortens its half-life and turns it red. Though less lethal to Superman than the green variety, it turns his skin clear, making his body absorb huge amounts of yellow sunlight. This overpowers him so it takes all his will to keep himself from destroying everything around him.
*** Martian Manhunter gets his skin coated with nanites that convert loose atoms into magnesium. [[ArtisticLicenseChemistry This magnesium spontaneously combusts on contact with air]], trapping Manhunter in a ball of fire.
*** For Wonder Woman, Batman knows that her determination in battle will never die. A device makes her hallucinate so she thinks she's facing unending waves of enemies, with no chance ever to rest. She can't interact with the rest of the world, and eventually her heart will give out.
*** Green Lantern (Kyle) gets a mental suggestion that makes him block his eyesight with his power ring. Blinded, he can't use his ring for anything else.
*** For the Flash, there is an implant that gives him constant uncontrollable seizures at light speed. After 20 minutes of seizures he thinks he's been in them for days, in such pain that he prayed just to die.
*** Aquaman is dosed with an altered version of the Scarecrow's fear toxin. He becomes terrified of water, leaving him dehydrated and due to die in a matter of hours.
*** Plastic Man is frozen solid and smashed to bits.
**** What's also interesting is that most of these use tech from Batman's own RoguesGallery. Plastic Man's comes from Mr Freeze. Aquaman's comes from Scarecrow. Wonder Woman's comes from the Mad Hatter. Manhunter's may come from Killer Moth, and Green Lantern's may come from Hugo Strange. It's possible that Deathstroke's confiscated tech was used against the Flash.
** The ''ComicBook/SupermanBatman'' comic ''combines'' the this and KryptoniteRing: After a long-term mission to destroy all the kryptonite on Earth, Superman saves one piece, which he gives to Batman for emergencies. Batman takes it to a lead-lined room in the deepest area of the Batcave... which is ''already'' filled with multiple kinds of kryptonite!
* A very dark version occurs in ''{{Irredeemable}}'', where BadassNormal the Hornet stops trusting his team's Superman-expy the Plutionian when the latter refers to the Hornet's wife by name, which the Hornet hadn't revealed. Realising that this ally with god-like powers is spying on his team-mates, and that the Plutionian has a human personality with human faults, the Hornet looks for weapons against him.
** His chance comes when Earth is invaded by an alien conquering race called the Vespa. The Hornet offers them teleportation technology (incredibly rare in this universe) and the co-ordinates of peaceful and defenceless planets his team has encountered, on the promise that the Vespa won't attack Earth, and will return to fight the Plutonian if the Hornet asks them to (using a DeadmanSwitch failsafe so that if the Hornet ''doesn't'' signal them every month, they know its time to come fight the Plutonian). [[spoiler: The plan works, with the Plutonian captured and imprisoned by the Vespa. Temporariliy at least.]]
* The Xavier Protocols in the ''ComicBook/XMen'' comics are a detailed set of files compiled by Professor Xavier detailing the weaknesses of every member of the X-Men, as well as members of many of their spinoff groups, and plans for the quickest and most efficient ways to kill each of them. When the Protocols are revealed during the Onslaught event, it comes to quite a shock to Xavier's students, and they remain a sore spot in the X-Men's ongoing history.
** Notably, the Xavier Protocols include a file for Xavier himself as well, unlocked by brain-scan verification of the presence of Moira [=McTaggert=], Cyclops, and Phoenix and containing schematics for a suit of anti-psionic armor which turns out to be essential for the fight against Onslaught.
** During Grant Morrison's run on ''New X-Men'', the Professor revealed another, much more direct insurance against himself. In case his mind ever gets hijacked by another, more malicious telepath, he keeps a gun in his chair with which to blow his brains out.
* ''ComicBook/IronMan'' is also guilty of this, having "-buster" armors for his fellow heroes should they go rogue, with the Thorbuster and, of course, the much more well-known Hulkbuster ([[NamesTheSame the same name]] as the group that's organized by Thunderbolt Ross for the same purpose).
[[/folder]]

[[folder:Literature]]
* The AnitaBlake series has characters set such things up for themselves when they realize how close to [[JumpingOffTheSlipperySlope the edge]] they're getting. Anita is none too happy about being Jean-Claude's, and it's implied later that it's because she has to find someone else to do this in case ''she'' ever goes bad.
* In StarTrekColdEquations, the leadership of the Breen Confederacy tries to pull this on the Gorn, telling them that the Gorn Hegemony is the weak link in the Typhon Pact alliance because of their previously almost-friendly relationship with the Federation (the Breen, along with the Tholians and Tzenkethi, view the Pact in part as a means of triumphing over the Federation). The Gorn agree to serve as a distraction as part of a Breen plot, by seeking a private summit with the Federation President at which they drag out proceedings pointlessly, but they have misgivings when it becomes clear the Breen see them as expendable. When confronted about it, the Breen tell the Gorn Imperator that they suspected his people would eventually seek to form a relationship with the Federation anyway, but if he ever tries to get close to the Federation again, they'll remember the fiasco that took place this time and reject them. The Breen call it "a preemptive investment in your loyalty". [[spoiler: This backfires when the Gorn privately vow to repay the Breen for their treachery and start channelling intelligence on Breen politics to the Federation, while seeking to strengthen their ties with fellow moderate Pact member, the Romulans]].
* In Literature/TheLostFleet, Rione mentions that a large part of why she had originally befriended Geary was to be able to kill him if he ever tried to take over the alliance.
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[[folder:Live-Action TV]]
* On ''{{Smallville}}'', Chloe has (or had) caches of Kryptonite stashed around the world, in case Clark goes bad again. Clark didn't know about them for a while.
* On ''Series/{{Angel}}'', Cordelia keeps around crosses and other anti-vampire equipment in case Angel [[EnemyWithin loses his soul]] again.
* [[Series/HogansHeroes Colonel Hogan]] seems to factor this in to all his plans. When blackmailed by a Gestapo agent for a million dollars in diamonds, Hogan deliberately tips off Klink to part of the deal (obviously not telling him that Hogan is secretly running an escape and sabotage unit right under Klink's nose) so that if the Gestapo agent tries to kill them anyway, Klink will (unknowingly) save their lives, and if the agent sticks to the deal, the Heroes will cover for him and let him get away. Even day-to-day operations involve this - Sergeant Schultz "knows nussing" and turns a blind eye to their antics and even helps the crew out on occasion because if he were to report anything of what he's seen, he would immediately be transferred to the Russian front because he's responsible for preventing things like that from happening. Their insurance on him forces him to help keep the status quo.
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[[folder:WebOriginal]]
* In the WhateleyUniverse novel "Ayla and the Mad Scientist", Phase has been pulling a Batman on this. As the holographic simulator jockeys run the team through a series of 'Dark Phoenix' scenarios, Phase has lists of methods for taking out all of his teammates. And himself. His team all know about this, and none of them are surprised. After all, this is a fifteen year old who doesn't plan to be a superhero but already has a loaded utility belt.
[[/folder]]

[[folder:Web Comics]]
In ''ComicBook/PS238'', [[spoiler: the American goverment create Argos's KryptoniteFactor (Argonite) in case he ever goes evil. Then they tell him it came from the destroyed remains of his homeworld, which is just BlatantLies]]
[[/folder]]

[[folder:Western Animation]]
* Much like the comics, animated Batman, in all different forms, practices this trope.
** In ''WesternAnimation/BatmanBeyond'', the aging Bruce Wayne seems to have been keeping a piece of Kryptonite locked away for years just in case.
** In ''WesternAnimation/JusticeLeague'', the android A.M.A.Z.O. manages to copy Superman's powers, after which Batman pulls out a piece of kryptonite and manages to subdue A.M.A.Z.O., at least temporarily.
--->'''Hawkgirl:''' Do you always keep that in your belt?\\
'''Batman:''' Call it insurance. ([[GrapplingHookPistol grapples away]])\\
'''Hawkgirl:''' And they say I'm scary.
*** It's even fore-shadowed in the preceding episode, Batman and Superman have a falling out over the latter's supposed obsession with killing Darkseid. By the end of the episode, Superman glares somewhat menacingly at Batman, saying "you're not always right". Cue the next episode, where Batman shows up with kryptonite.
** ''WesternAnimation/TheBatman'' has an incredibly cynical version. When Batman got a piece of kryptonite off of Metallo, not only did he keep it, he ''lied about giving it back'' (he gave Supes a fake one and kept the real one). He did it to "get even" with Superman for finding out his identity. However, by the end of the episode, it's the idealistic version, as they have settled their differences, and when Batman offers to give Supes the ''real'' kryptonite, Superman says to keep it. It still goes to show you that Batman really doesn't like anyone being nearly as CrazyPrepared as him.
*** This is also used by the end of ''The Batman'': Batman gives each member weapons that simulate each League member's weaknesses because aliens have invaded and copied their powers.
** Batman makes an oblique reference to having Kryptonite in reserve in ''ComicBook/JusticeLeagueTheNewFrontier'', when he warns J'onn J'onzz that he [Batman] knows ''his'' weakness [fire], too.
--->'''Batman:''' I have a seventy-thousand dollar sliver of radioactive meteor to stop the one in Metropolis. With you, all I need is a penny for a book of matches.
** In ''WesternAnimation/YoungJustice'', the League is brain washed and forced to fight the team. Superboy grabs Superman so Robin could expose him to enough sliver of Kryptonite that weakens him until so that they can apply the cure-tech. Superboy comments that Kryptonite ''hurts'', "Which is why Batman keeps it in an overwhelmingly impenetrable vault in the Batcave... well, more like a ''whelmingly penetrable'' vault."
** In ''WesternAnimation/BatmanTheBraveAndTheBold'', Batman reveals that information about his friends' respective weaknesses is stored in his computer just in case they go bad. Owlman, his EvilCounterpart from a MirrorUniverse, uses the information to capture the other heroes.
* ''WesternAnimation/JusticeLeagueDoom'' is an adaptation of the "Tower of Babel'' storyline, with Vandal Savage and members of each hero's Rogues' Gallery pulling it off. Batman mentions that each plan was supposed to be non-lethal, but Savage made adjustments in order to kill the League. Some of the plans were different from the comics:
** Superman is tricked by Metallo disguised as a suicidal man, and shot with a Kryptonite bullet.
** The Flash gets a bomb impaled through his wrist. The bomb has a three-mile blast radius, and will go off if he slows down.
** Green Lantern (Hal) is tricked into a faked situation in which a civilian (with a strong resemblance to Carol Ferris (Star Sapphire)) is killed, while exposing him to a variant of Scarecrow's fear gas to sap his will.
** The scenarios for Wonder Woman and Martian Manhunter were the same.
** While the remains of Batman's parents are still stolen, unlike the "Tower of Babel" storyline, Batman is knocked out after finding out about the theft and is buried alive while inside the coffin of one of his parents.
* In the ''WesternAnimation/{{Legion of Super Heroes}}'' animated series, it's Brainiac 5, otherwise portrayed as Superman's ''[[HoYay very loyal]]'' RobotBuddy, who keeps Kryptonite for emergencies. This is very much the cynical version; Superman not only doesn't know Brainy has it, but he doesn't even know Kryptonite exists yet.
** Although Brainy seems conflicted about having the stuff; after it's been stolen, he says he's glad to be rid of it.
* In ''WesternAnimation/GeneratorRex'', White Knight uses a mechasuit when he is forced to leave his sanctuary in Providence to help Rex with a world wide problem. Rex realizes that the suit was in fact originally designed to take ''him'' out if he ever went rogue on Providence.
** [[spoiler:Agent Six]] was also ordered to kill Rex if he ever [[spoiler:became his evil giant robot self again]].
* In ''WesternAnimation/TeenageMutantNinjaTurtles2012'', Dogpound attaches a collar to Baxter Stockman's neck with small canisters of mutagen attached to it, threatening to release the mutagen if Baxter doesn't play nice (he had previously trapped Dogpound and Fishface in a deadly obstacle maze). [[spoiler:Given concept art of a mutated Baxter exists, it's fairly safe to say that this will probably be activated, though how and why has yet to be revealed.]]
[[/folder]]

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