Dead Man's Switch

aka: Dead Man Switch

Don Harvey: So, hanging on to this switch prevents the bomb from going off, correct?
Capt. Rhodes: Correct. Are you sure you're up to it?
Don Harvey: I'll remember to hang on tight, sir.
Capt. Rhodes: I'm not worried that you might forget to hang on, Mr. Harvey; what I want to know is this: if it becomes necessary to let go of that switch, can you do it?

— Between Planets

A backup plan in case of untimely death or incapacitation, used as a threat to protect the holder. If that person dies or fails to issue some form of communication within a set period of time, the plan goes into action automatically, making it in the interests of the threatening party to not harm that person. Provided, of course, that the threatening party knows about it. A common plot involving this trope is the switch is put in danger of being accidentally set off by somebody who had no way to know about it, or something in the system itself breaking causing it to reject attempts to turn it off.

A more common twist that is beginning to appear is that of the hero simply cutting off the hand or arm, thereby removing the threat entirely.

If an entire government or culture has a Dead Man's Switch, it usually sets off a Doomsday Device.

The Trope Namer is a device installed on train locomotives and heavy equipment that shut down the equipment if the operator dies, falls asleep, or otherwise loses control of the machine. Oddly enough, though, you don't see it really used on trains in fiction... or cars for that matter. The real-life counterpart to the threat aspect of this trope is a fail-deadly system.

A Super-Trope to Load-Bearing Boss, which usually applies to video games. See also Defeat Equals Explosion when the dead man switch is part of the holder. This can be a Sub-Trope of My Death Is Just the Beginning, if the plan is big enough. It's also a subtrope to The Dead Guy Did It. In some cases, the holder may trigger it deliberately to invoke Taking You with Me. May overlap with Death-Activated Superpower and Thanatos Gambit. Compare Betrayal Insurance.

As this is a Death Trope, all spoilers will be unmarked ahead. Beware!

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Examples:

Anime & Manga

• In Campione!, Erica blackmails Liliana about the erotic novels she secretly writes. Erica memorized them and inserted their contents in her will, so Liliana can't kill her to keep it secret.
• In Case Closed, Conan employs a Dead Man Switch on a tape recorder to keep Vermouth from killing him after his plan to capture her goes south and he's captured instead. If the recorder is disconnected or he dies, her boss's ringtone and all conversation captured will be sent straight to the police.
• In Code Geass, during his final standoff with Suzaku at the end of season one, Lelouch/Zero straps a bomb to himself that he claims will detonate if his heart stops. The writers admitted that it was added when they realized that otherwise, his opponent would have just shot him. When the cliffhanger is picked up next season, Suzaku tackles him to the ground and removes the bomb.
• Death Note:
  • Rem lets Light know that if Misa dies unnaturally, she'll assume Light did it and kill him.
  • L was able to safely reveal his identity to Light in private once L made it clear that, if he were to die soon after, other people would be able to use it as evidence that Light (the prime suspect) was the murderer.
  • Watari maintains a computer link to the orphanage he runs, and reports in at regular intervals. When Rem kills both him and L, at the proper time the computer reports "L is dead". This is a cue for the man currently operating the orphanage to send out L's successors, Near and Mello, to continue the Kira investigation.
• In Eureka Seven, Colonel Dewey pulls a literal Dead Man Switch upon his suicide, in which a collar that Eureka had been wearing through out the series forces her to become a second Control Cluster which will cause the end of reality as we know it. This from the guy whose stated aim was to save the world. He rationalizes minutes before that the Scub has irreversibly tainted the world, and thus it is better off not existing.
• Uryuu Minene uses one of these in Future Diary when she holds up a school, derailing an attempt to snipe her because it's attached to a bomb.
• In Hunter × Hunter Netero turned out to be wired to a "Miniature Rose" bomb that detonates when his heart stops in case he'd lose to Meruem.
• Subverted in JoJo's Bizarre Adventure: Battle Tendency when Lisa Lisa manages to get the Pillarmen to spare her and Joseph (for the moment) after bluffing that the Red Stone of Aja, which the Pillarmen really need, will be destroyed by a time bomb. They settle for sending Joseph to get it and battling for it, though Kars cheats in his battle, not caring about honor, only the stone.
• The Mobile Suit Gundam Wing sequel manga Frozen Teardrop has a particularly extreme version of this: the Perfect Peace Plan, in Relena Peacecraft's death would cause the Nanomachines secretly administered to Martian colonists to form blood clots and kill an estimated three billion people. Relena had to be put in cryogenic stasis until such a time as a solution could be devised.
• One Piece: In the Egghead Island arc, when Stella Vegapunk dies due to the actions of both Saint Saturn and Kizaru, his fading heartbeat triggers a computer system that will broadcast the World Government's secrets to the world. However, there is a delay of 10 minutes to allow the people to prepare visual Transponder Snails for the broadcast, leading a race against time between the Five Elder Stars and the Straw Hats.

Comic Books

• Dark Times: When Jedi Master Kai Hudorra tries to bluff Darth Vader with a thermal detonator set as one of these, Vader simply keeps it pressed with The Force, 'sabers the guy up, and then blows the place anyway just for the heck of it.
• In Fables, a plucky reporter investigating Fabletown (actually, he's under the impression they're vampires) has a system set up that if he's killed, all the information he's gathered about Fabletown will be released to the press. The Fables have to arrange an elaborate blackmail/con to convince him to defuse the threat. And then Bluebeard kills him anyway.
• In Forever Evil (2013), villainous speedster Johnny Quick attacks Captain Cold and relieves him of his trademark gun, taunting Snart by twirling it in front of him. An annoyed Cold voices a codephrase, which sets the gun off and freezes Quick's leg at the thigh.
• G.I. Joe: A Real American Hero (Marvel): The first issue of G.I. Joe Special Missions features a terrorist group who've hijacked an airplane; one terrorist wears an explosive vest with a dead man switch set to go off if he releases the trigger. He gets zapped with a taser, causing all of his muscles to contract while incapacitating him.
• In one issue of Global Frequency, a group of terrorists are wearing suicide vests that will go off if they die, killing their hostages. They're also planning to poison themselves if their demands are not met. Subverted in that the head terrorist was just planning to push the button as soon as he felt the first spasm of poison. Once the Frequency agents hear this, they just blow away the leader's hand.
• The Incredible Hulk: When Bruce Banner starts working for S.H.I.E.L.D., he first sets up one of these in case they decide to just kill him to neutralize the threat presented by the Hulk. Prior to his initial meeting with Maria Hill, he steals highly classified information — implied to be damning enough to bring down the whole organization if released — and gives it to a contact (who turns out to be Daredevil) along with instructions to release it if Banner doesn't check in with him on a regular basis.
• The prequel comics for Injustice: Gods Among Us reveal that Metropolis was destroyed by a nuclear bomb that was set off by a dead man switch in Lois Lane, who Superman killed by taking her into space, because he was under the effect of a Kryptonite-induced fear toxin that made him hallucinate that she was Doomsday. And to make matters worse, she was also pregnant with his child. The mastermind of this horror was none other than the Joker, who did all of this because he was bored with losing to Batman all the time and wanted to "liven things up a bit". This is the catalyst for the Start of Darkness for this universe's Superman, who brutally murders Joker in vengeance and then goes on to set up a dictatorial One World Government so that nothing like this can ever happen again.
• In The Punisher: Suicide Run, when The Punisher finds himself in a trap set up by various criminal elements, Frank plants explosives on the bottom floor of the skyscraper they're meeting in. When the trap is eventually sprung he tells his enemies that he has his finger on a dead man's switch, and is ready to blow them all away. He then proceeds to start shooting, and there's nothing that the criminals can do to stop him.
• The Sandman (1989): One story in the Endless Nights book has a version of this combined with He Knows Too Much. An archaeologist called out on a seemingly ordinary dig discovers it's not so ordinary. When The Men in Black finally come in and try to close down the site, the archaeologist reveals that a bot will email a detailed account of the dig to multiple online news sources unless she checks it every 24 hours. They let her go.
• Superman:
  • In one Villain Team-Up between Lex Luthor and Brainiac to take on Superman, Lex gave Brainiac an upgrade, but arranged it so Brainiac will automatically shut down every few hours unless Lex is around to turn him back on. Lex explains this is to ensure Brainiac doesn't betray or abandon him. Eventually, Brainiac hypnotizes Lex into removing that feature.
  • In The Death of Clark Kent, after Kenny Braverman dies, a mechanism is set off that tries to kill Jimmy Olsen and (if possible) Superman along with him.
• The Transformers Megaseries: Grimlock sets one up in Transformers Spotlight: Shockwave before the Dynobots go to fight Shockwave. Once they all get put into stasis lock, the ship fires on a nearby volcano, burying all six combatants.
• X-Factor (2006): Taylor and Arcade plant bombs across Mutant Town and rig them to detonate when Taylor's heart stops beating. After their initial plans to kill X-Factor fail, Taylor resorts to poisoning himself, detonating the bombs and destroying Mutant Town.

Fan Works

• In Amazing Fantasy, the Prowler holds Mount Lady hostage by planting a bomb in her neck while holding a detonator with a dead man's switch. All Might rescues Mount Lady by using his Super-Speed to snatch the detonator and bind it with duct tape before the release could trigger. He then throws the detonator into the next prefecture, far out of the effective range to signal the detonation.
• In Evolution, Moya Jones must contact her superiors at regular intervals or else all the information she has on both Cole MacGrath and Alex Mercer will be sent to them as insurance should the both of them decide to kill her.
• The Great Ace Detective: Mael Stronghart had a back-up plan in case he was killed by Klint van Zieks. Namely, the autopsy report of Genshin Asogi getting sent to Herlock Sholmes, revealing that Genshin didn't die by the Professor's hound as reported but rather in a duel to the death.
• Haigha: As a precaution against Izuku being a potential Manchurian Agent, all of the staff members at U.A. are given devices that monitor their vitals. This comes in handy during the USJ, when three signals are simultaneously cut off by the invaders. Afterwards, they decide to keep the system in place, contemplating making it standard gear.
• In Harry Potter and the Nightmares of Futures Past, the Dursleys are prosecuted for their abuse of Harry — but their solicitor is clever enough to blackmail the Ministry with documents held by third parties, containing signed depositions regarding their interactions with Harry, to be mailed to Muggle publications if the prosecution goes ahead. The Ministry is annoyed, but agrees to drop the charges in exchange for avoiding a breach of the Statute of Secrecy.
• Mastermind: Strategist for Hire: Izuku has two separate dead man's switches set up to release murder plans for the top 50 Pro Heroes if he is captured or killed. One is a program written by La Brava, the other is that Giran has a copy of said plans with instructions to release them if anything happens to him.
• The New Adventures of Invader Zim: As revealed in Season 2 Episode 13, Norlock had one in place, namely an urn containing a Nightmare Weaver magically compelled to go after anyone who was near him at the time of his death, sealed up with a mystic time lock only he could reset; with his death at the climax of Season 1, there was no one to stop it from being released.
• In Origins, a Mass Effect/Star Wars/Borderlands/Halo Massive Multiplayer Crossover, clones of Athena are wired with such a device combined with Hollywood Acid to avoid Transformation Horror courtesy Parasite Zombies.
• In The Powers of Harmony, Ophiuchus has a variant of one of these. Namely, as the subconscious of Horizon, he can break the barrier over the Gate of Tartarus whenever he wants. Such a thing will obviously kill him, but he uses it as an ultimatum to control Blair and the other Echoes.
• In the first part of the Start Again series, The Count of Monte Crisco, Haru blackmails the Black Mask into taking her into the Metaverse and not to kill Wakaba Isshiki or she will tell the public that he, Goro Akechi, is really Masayosho Shido's bastard son and has been killing on his behalf^note Ironically, Akechi hasn't joined Shido at that point of time, and Haru's action prevented him from joining outright, and the news will be released if anything happens to her. It works, and Haru permits Makoto to keep the information in case the Black Mask goes after her. Makoto later uses the information to get the Black Mask to help save Haru when she gets overwhelmed in Kamoshida's Palace.
• A Thing of Vikings: Mildew warns Mac Bethad that if the latter kills the former, letters will be dispatched to Stoick explaining everything they did. It took over a year, but Mac Bethad's people managed to locate those letters, destroy them, and kill the people who had possession of those letters. Except they missed one. Mildew told Peader and presumably most of the others that he'll send them letters every four months. Taskill managed to trace these to Peader and the other possessors of the incrimating letters. However, he told Fraser that he'll contact him yearly. Without a letter to Fraser to trace, he escaped the fate of Mildew's other contacts. The incriminating letter Mildew gave him is still intact. Overall the plan is decent but nearly fails because no one actually likes Mildew all that much. The remaining letter winds up gathering dust in a tavern keeper's papers while he decides what to do about it... until it is seized by Berk as part of entirely unrelated fraud charges. It reaches Stoick and alerts him to Mac Bethad's treachery merely hours after Hiccup's retinue leave to talk to Mac Bethad about his spies.
• The Unabridged Memoirs of Darth Plagueis the Wise: Plagueis and Dooku both claim to have one ready to expose the other's corrupt dealings, in case of an assassination. Dooku's is eventually revealed to be a hologram recording wherein he confesses to his crimes and implicates Plagueis in them which Plagueis finds and replaces with a forged copy, featuring Zam Wesell impersonating Dooku and "confessing" to being Darth Sidious.
• With This Ring: A Reach ambassador attempts to blackmail Paul into leaving a world under her control, by wiring every incubation facility on the planet with detonators, and placing several dozen possible triggers, so if he tries to brand or assimilate or otherwise Mind Control her, or just kill her, the bombs will go off and kill every infant on the planet. He merges with the Ophidian and uses her power to move all the infants into subspace simultaneously; the explosives are triggered by this, but the children are already safe.

Films — Animation

• Batman: Hush: Hush stops Poison Ivy from attacking him by saying his vitals are hooked up to a herbicide bomb.
• In Zootopia, a proper train dead man's switch is shown when Nick and Judy find Doug's night howler lab, in an abandoned subway car. During the escape scene, Nick is shown having to apply constant pressure on the switch and deliver even more when Judy tells him to accelerate, which puts said character into the Non-Action Guy role in order to keep the escape going.

Films — Live-Action

• In Analyze This, mobster Paul Vitti declares that he wants to get out of the Mafia, and he knows some of his fellows Dons might have issue with this, so he's written down "a few things" about every other mob boss and put the documents in safe hands in case somebody decides to do him in.
• In The Big Heat, Mrs. Duncan's arranged to have her husband's confession/suicide note sent to the press in the event of her death. The Mafia is more than happy to pay her off, but someone with a grudge against the mob boss then murders her so the document will be released.
• Billion Dollar Brain: Midwinter's men catch up with Anya just as she's picked up the Styrofoam case holding the eggs that have been filled with a deadly virus. She just raises the case and threatens to smash them if they try to detain her.
• Black Crab: Soldiers catch Caroline Edh after she's stolen the weaponized virus from the laboratory, only to reveal she's taped the two vials to a hand grenade and is holding down the safety lever. The admiral tries to persuade her to hand them over, but she works her way to a ledge above the sea and jumps off, detonating the grenade in mid-air to destroy the virus.
• Blown Away: The cop Jimmy Dove sneaks up on Mad Bomber Ryan Gaerity and puts a gun to his head, but Gaerity then shows his finger is resting on a radio detonator. Dove tells him to go ahead and blow them both up, but Gaerity says the bomb is actually at the concert where Dove's wife is. Gaerity then tricks Dove into stepping on a pressure detonator which holds him in place while he activates the real detonator, because he was actually lying about the first one.
• In Captain America (1979), the superhero fights a villain trucking a Neutron Bomb for a terrorist plot by not only attacking the driver, but bending an exhaust pipe so it vents into the trailer to subdue any guards of the bomb. Unfortunately, when Cap investigates inside, he finds out that the main villain was in there, is near death from his attack and he has a Dead Man Switch that would detonate the bomb if the villain's heart stops. Thus, Cap and his Mission Control superior have to frantically apply first aid to prevent the detonation.
• The premise of Crimson Tide basically deals with this possibility on a government-wide level (see Real Life examples below).
• The grenade version is also used during the opening robbery in The Dark Knight, when customers in the bank being robbed are forced to hold grenades with the pins taken out. They're actually smoke grenades, judging by the one given to the bank manager — it's a bluff, or possibly the Joker's idea of a prank.
  "Obviously we don't want you using your hands for anything other than holding on for dear life!"
• Done with an actual dead man in The Dogs of War. In the Action Prologue, the mercenaries are escaping a Central American country on the last plane out, and insist on bringing everyone.
  Official: This man's dead! Get him out!
  [mercenary removes the pin from a grenade and wraps the dead man's fingers around it]
  Mercenary: He's live, you pimp!
  [fingers loosen slightly on grenade; official backs off]
  Mercenary Commander: Everybody who comes with me, goes home.
• Dr. Strangelove and the whole Soviet "Dead Hand" protocol. The big irony in this movie was that the Soviets hadn't got around to actually telling the world when General Ripper ordered his bombers to attack.
• At the end of Dredd, Ma-Ma tries to use one of these to get Dredd and Anderson to back off. It's hooked to her wrist, monitors her heartbeat and will set off all the explosives she's stashed on her floor — of which there are enough to level the upper stories of the megastructure. Dredd shoots her in the stomach without immediately killing her, notes that they are a kilometer above ground, and asks her if the signal is strong enough to get through 200 levels of concrete before throwing her off the balcony. As it turns out, it's not, denying her posthumous retribution.
• Elysium: To get a ride up to Elysium, Max holds a grenade with the pin removed to his head which holds the information Kruger's employer has sent him to retrieve. Kruger pretends to fold and coaxes him on board the Raven...where he has Frey and her daughter prisoner, so if the grenade detonates Max kills them as well. Then when they've almost reached the space station, Kruger and his men try to grab the grenade and things don't go well after that.
• In The Firm, when Mitch assures the mob that their secrets are safe, he also issues a veiled threat by letting them know that he knows all their dealings (purely to better serve them as their attorney, of course) and that he's made copies. But don't worry, he is bound to respect attorney-client confidentiality for as long as he lives — emphasis on lives.
• In Goldfinger, a captured James Bond bluffs that his death or vanishing will just activate another agent who will share Bond's knowledge of Goldfinger's "Operation Grand Slam" plan, presumably one that would assume 007's loss to be the direct result of Goldfinger himself. While Goldfinger at first (and correctly) concludes that Bond only knows the name of the plan, Bond convinces him that that is a chance he can't take. Goldfinger thus decides to keep Bond alive so that MI6 still believes him on top of things and won't send another agent who has Bond's knowledge and is at liberty.
• The Big Bad of Hancock is holding a Dead Man Switch that will detonate a bomb attached to his hostages if his finger releases the trigger. Hancock takes his hand with him.
• A legal variant in Hitman (1998). A Yakuza/war criminal type boasts he is protected by a "Revenge Fund" that will activate if he is killed, which promises a phenomenally large reward to the one who tracks down his killer. True to form, the entire city's Underworld wakes up at the promise of money when he is actually murdered.
• In I, Robot, Dr. Alfred Lanning left behind instructions for Del Spooner, in the event of his death. His suicide near the beginning of the film sets in motion Del's investigation.
• In Last Sentinel (2023) someone activating the Doomsday Device has to hold down a pressure switch before entering the activation code. Which leads to Fridge Logic in a scene where someone is entering the code and the others can't rush him because he's holding down the switch, except it shouldn't set off the bomb yet because he hasn't finished entering the code.
• Lethal Weapon (1987): During the hostage exchange, Murtaugh takes a grenade from his pocket, removes the pin and says he'll blow them all up if his daughter isn't released first. It's a smoke grenade.
  Joshua: Shoot him!
  Mercenary: He has a grenade!
  Joshua: He's bluffing! He'd never risk harming his own daughter.
  Murtaugh: If she's going to die, she's going to die with me! My way, not yours!
• Lock Up: In the climax, Frank Leone takes the evil Warden Drumgoole hostage and throws him into the reactivated electric chair in the prison's defunct death row section. Then he ties his hands to the switch, so he can make his speech about all the bad things the Warden did to the guards while they're unable to shoot him. Frank was bluffing. The chair was never active.
• In Machete Kills, Mendez has the missile programed to launch if his heart stops, preventing Machete from killing him. Voz eventually kills him, but keeps his heart functioning in a jar.
• In Point Break (1991), Bodhi tells Johnny Utah that if doesn't meet with another robber at a certain place, that robber will kill Utah's girlfriend.
• The Punisher (2004) has a variation where Frank Castle forces John Saint to hold down the pressure plate of an anti-personnel mine one-handed. Even though John's a fit man, he can only do this for so long before his Sound-Only Death.
• In Ronin (1998), Stellan Skarsgård's character does this when "negotiating" over the case. He has to call by a certain time, or the Russian's girlfriend will be shot by a sniper. The Russian elects to let her die.
• In Saw III, Jigsaw has his heart rate monitor hooked up to a device that will kill Lynn if he flatlines, which he eventually does when her husband Jeff kills him. This example of the trope has a twist in that it's not about preventing somebody from killing him, but coercing them into keeping him alive (despite John's late-stage cancer) for as long as possible.
• The Soldier. The Heroes "R" Us have to seize an ICBM base. When they reach the launch control room, one of the airmen there holds down a Big Red Button on an extendable cable before answering the door. When they burst into the room, our heroes have to grab and hold down the airman's hand before knocking him out, so he won't release the button and set off an alarm.
• In Spawn (1997), CIA director Jason Wynn, who Spawn wants dead for sending him to Hell, has a device installed near his heart that, if his heart ever stops, will send a signal out to an automated system designed to release a devastating virus all over the Earth. Oddly, even the "normal" members of the CIA are shown thinking that this was a good idea. ("Now, no one will dare kill you, sir!) It apparently never occurs to anyone to think about what would happen if the guy gets into a car crash, has a heart attack, or is assassinated by somebody who doesn't know about the top-secret weapon. When informed about this, Spawn manages to use his magic to remove and deactivate the device.
• Speed:
  • Howard Payne has a bomb wired to a Dead Man Switch, so that if he is killed, his finger releases the switch and it goes off. He does this while taking the Love Interest hostage, since last time he tried this he was the victim of Shoot the Hostage. The main trigger for the bomb is also a Dead Man Switch, activated if the bus drops below 50.
  • The bus also has a second Dead Man Switch in that the bomb will be triggered if anyone tries to get off, and with a plethora of news crews filming and a secret camera installed on the bus, Payne will know if someone tries. In essence, he's installed two switches, one that will blow if his instructions are disobeyed while he's alive, and one if the same happens when he's dead.
• A plot point in The Taking of Pelham One Two Three, about the hijacking of a New York City Subway train for ransom. The police are wondering how the criminals intend to get away, and suggest they might try jumping off while the train is moving. The dead-man's handle is explained; however the criminals rig up a construction that holds down the lever for them.
• Tenet. Andrei Sator has a device that constantly measures his pulse. If it ever stops, an email will be sent that reveals the location of The Algorithm, ensuring that it will be found and used in the future. However Sator is Secretly Dying, so the intent is not to deter his death but to take the rest of the world with him.
• Terminator 2: Judgment Day: Inventor Miles Dyson makes a Heroic Sacrifice by standing between the escaping heroes and a pursuing SWAT team, hand-holding a heavy piece of wreckage over a detonator switch as his last labored breaths flutter from his bullet-riddled body. It also shows that he doesn't really want to kill them, as he warns them to get out.
• An unintentional version in Thor: Ragnarok: Odin's death triggers the release of his rebellious daughter Hela from the prison he sealed her up in many eons ago, freeing her to conquer Asgard.
• In The Usual Suspects, Kobayashi lets the protagonists know that if he dies under suspicious circumstances, his boss Keyser Söze will immediately know who did it and take revenge on them and their families.
• WarGames: At the end, WOPR attempts to extract the silo launch codes itself. General Berenger asks why they don't simply shut WOPR down, but the techs answer that the system would interpret this to mean that NORAD has been destroyed and initiate an automatic "counter-strike" against the USSR.
• Wrong is Right. A Middle Eastern dictator threatens to set off a couple of suitcase nukes in New York if his demands aren't met. At one stage the US President is desperate enough to consider nuking the dictator's entire country, but it's pointed out that the bombs could have been set to detonate if they don't receive a signal.

Literature

By Author:

• From Robert A. Heinlein's writings:
  • In Between Planets, to prevent the ship Little David from being captured by the Federation, it has a bomb attached to a Dead Man Switch, to which Don Harvey is assigned as his battle station.
    Capt. Rhodes: ... I'm not worried that you might forget to hang on; what I want to know is this: if it becomes necessary to let go of that switch, can you do it?
  • A better one is in The Long Watch. A colonel on a nuclear missile base on the Moon launches a Military Coup, so his Bomb Officer locks himself in the room where the nukes are stored. To prevent the colonel blowing the airlock and killing him with Explosive Decompression, he rigs up a deadman switch. He hasn't the guts to kill himself and set them off and foil the coup that way, but if it only works if he's dead...
  • This backfires in Podkayne of Mars. Podkayne's brother Clark has got hold of a minature atomic bomb. He sets the bomb to explode so their kidnappers will get killed if their escape attempt fails. It succeeds, but he forgets to defuse the bomb in the excitement, and when it goes off his sister is still within the blast zone.

By Title:

• In Against a Dark Background, the Big Bad claims to have rigged his Dead Man's Switch to a whole network of bombs rigged destroy most of the critical infrastructure in the star system in which the novel is set, plunging it into (yet another) post-apocalyptic dark age. The heroine is unimpressed, and messily kills him anyway. (The ending is ambiguous about whether he was lying to try to keep her from trying that.)
• In Matthew Reilly's Area 7, the villain Caesar traps the President and his bodyguards in a remote facility, and has placed a transmitter on the President's heart. If his heart stops beating and the signal stops, dozens of nuclear bombs around America will detonate. However, in the case that the President survives and Caesar and his men die to the President's bodyguards, Caesar has placed a transmitter on his own heart, that will detonate the bombs if he dies.
• The short story "A Brief History of Death Switches" by David Eagleman, though the eponymous death switches are not of the revenge sort but rather the "communicating from the grave" sort.
• In the Codex Alera series, the High Lord Kalare has one of these. If he dies, he has magically set the Great Fury Kalarus to destroy his entire city, killing tens of thousands of people. One of the plot threads in Captain's Fury is centered around it, ending with the switch being intentionally set off early to end Kalare's rebellion.
• The entire village of Caer Dallben is protected by a magical version of this in The Chronicles of Prydain. Played with in that no one knows the "switch" even exists until an attack is attempted in the final book, since the village's protector, Dallben the enchanter, had mostly concealed the full extent of his powers up to that point in the story.
• In Dean Koontz's Frankenstein, Helios used several methods to ensure that his creations couldn't turn on him. One of these was a signal that would be sent out on his death, killing every one of his creations.
• Different Seasons: In Apt Pupil, Todd Bowden, while blackmailing Kurt Dussander, claims he left a letter (exposing Dussander) with a friend, to be opened and read in the event of his own death. Then when Dussander turns the tables and blackmails Todd, he claims that he left a complete account of Todd's actions in a bank deposit box, to be opened and read on the event of Dussander's death. They're both bluffing.
• In a slightly different example, Havelock Vetinari of Discworld fame installed multiple Gambit Roulette Dead Man Switches in the city of Ankh-Morpork which are neither magical nor mechanical, but political in nature, thus ensuring that a Discworld with him will be much better than a Discworld without him. However, he is also slowly taking the time to set up a proper police force and bureaucracy for the city, making sure that after he's gone, the city will still thrive.
• The Dresden Files:
  • Mavra in Dead Beat had one set up in one of the books. She had evidence that Murphy had killed people (they were Renfields) and that Mavra was going to send that evidence to the cops. In Mavra's words, "I won't kill her. I'll unmake her." Dresden quickly comes to the idea of killing Mavra. Seconds later, Mavra tells him that, unless she says otherwise, the evidence will still be sent. So if she dies, there's no one to rescind the order. Fortunately, at the end of the book, Dresden makes up for it by threatening Mavra in an incredibly ballsy and spectacular way.
  • Every wizard is potentially one of these. When a wizard is dying they can unleash a Death Curse that will seriously mess up its target. The scope of the effect varies by the power of the wizard. Some Death Curses will just strip the killer of all their magical power (potentially lethal to another wizard or magical being) while others might destroy a few city blocks or an island.
  • In the Side Jobs short story "The Warrior", the villain holds one of Michael Carpenter's daughters hostage with detcord (i.e., explosive dynamite-like cord) wrapped around her, with his hand on a dead-man's switch. If the villain dies OR Harry gets too close or uses too much magic (he is a Walking Techbane), it detonates.
• Done several times in Orson Scott Card's Ender canon:
  • Valentine threatens Peter with something like this in Ender's Game.
  • In the Ender's Shadow series, Bean and Petra are concerned that the Mad Scientist Volescu had one set up for after his capture, possibly triggering a virus to fundamentally change the human race. In a more heart-warming example, Sister Carlotta has a note prepared to be sent to Bean that will automatically be sent to him if she doesn't check in for a period of time. Considering that he only receives it after her death, he realizes that Carlotta cared enough for him to do something every day of her life.
• The Enemy Papers: In The Tomorrow Testament, an alien whose scheme has been uncovered asks those confronting him what would prevent him from killing them all right away. The answer is that a big fleet moves to bombard his planet, and if they are dead, no one will be able to cancel the current order in time. There would be some repercussions, a lot of turmoil... but this will happen after the fact.
• The Executioner:
  • When Mack Bolan takes on the San Francisco mafia, The Dragon insists that the soldiers of every underboss are brought under his direct control to deal with The Dreaded 'Bastard in Black'. He then smugly waits for Bolan to kill his boss so he'll have control of the entire city. Next thing The Dragon knows, his irate boss is on the telephone saying that Bolan strode into his house, killed all his soldiers and left him alive (as Bolan is running his own Batman Gambit). The boss declares that he's put out a sealed contract on The Dragon — if he dies by Bolan's hand, The Dragon also dies. Not knowing who, or even how many, killers might have the contract, The Dragon has no choice but to get serious about stopping Bolan.
  • In "Bloodsport", Bolan is posing as a corrupt army sergeant selling guns to terrorists, and uses the grenade trick (a tactic used by the same terrorists he's dealing with) to get them to put their guns away and talk business.
• In The Fate of Paul Twister, Amber tells a problematic duke that she's arranged one that will bring the wrath of the king down on his head if anything happens to her. It's left unclear as to whether or not this is a bluff, but he backs down.
• The Heartstrikers: Bixby wraps the unconscious Katya in enough explosives to level a city block, then holds a deadman switch to make sure the heroes can't kill him. They cut off his hand and Julius holds down the switch himself. But that proves to be its own problem, so Bob, the clan Seer, walks up and casually pulls a seemingly random wire, disabling the bombs.
  Julius: What are you doing!? How did you know that would work?
  Bob: I DON'T KNOW! It's almost as if I can see the future!
  Julius: ...oh. Right.
• Honor Harrington: There's a double version of this in Honor Among Enemies; a terrorist has taken over an entire planet, and when Honor tries to liberate it, he reveals that he has bombs planted under major population centres, which he can detonate himself, and will be detonated if she tries to take him out with an orbital strike; he uses this to bargain for safe passage out of the system. When he leaves the planet's orbit, he'll be out of range and can't set them off any more - so he insists on having Honor as a hostage until he can meet a waiting ship. Honor agrees, but brings her own dead man switch; a charge on the outside of their shuttle that will detonate if she doesn't enter a code at regular intervals. Unknown to the terrorist, she has another plan; her "switch" is concealing her old-fashioned gun, undetectable by common modern technology, and when they're out of range she uses it to kill the terrorist.
• A character negotiating with pirates in Invasion of Kzarch tries to use a deadman's switch and bombs to ensure his safety. The pirates simply toss him out of the gunboat and shoot him.
• In Leviathan Wakes, Naomi remotely programs the bomb Miller was carrying into the heart of Eros Station to blow up if its trigger was released for more than 5 seconds, ensuring it would still go off in case Miller was incapacitated.
• In the Millennium Series, counselor Bjurman rapes Lisbeth. Lisbeth secretly videotaped the event, and sets the video to be spread to authorities, if Lisbeth dies or gets captured.
• In John Grisham's The Partner, the eponymous character had stolen millions of dollars from his law firm and fled the country. When mercenaries track him down and abduct him, his failure to call in to his co-conspirator puts into action an elaborate plan to locate and free him.
• In Ragtime, when Coalhouse and his allies take over the Morgan Library and rig it with explosives, it's mentioned that Mother's Younger Brother has the detonator set up so that it will be triggered if he (Younger Brother) is shot. (This being the early 1900s, this just means that he's sitting in such a position that he'll fall on it if he dies.)
• In Revelation Space, Dan Silveste claims to have an antimatter bomb concealed in his tooth that will destroy everything within a kilometer if he dies or if his demands are not met. He's not bluffing, and he uses it during an entirely different situation as a suicide bomb.
• Raven from Snow Crash is very large, very deadly, and has poor impulse control, but the reason why almost everyone gives him a wide berth is that if you were to somehow kill him, allegedly a trigger attached to his brain would set off the (very real) nuclear warhead attached to the sidecar of his motorcycle. No one wants to risk it.
• In the Star Quest novel Roboworld by Terrance Dicks, Mad Scientist Faber finds that his android Ultimo is helping the heroes escape. To force him to comply, Faber pulls a lever that when released will detonate the anti-matter powering his asteroid base, and orders his android to kill the humans. Ultimo refuses, but can't stop his creator because he's not close enough to grab the lever himself. Fortunately, Faber decides it will be amusing to wait till just before the spaceship is about to launch. However, the heroes blast their spaceship straight through the hanger doors without waiting for them to open, so the asteroid blows up too late.
• Star Wars Legends:
  • In The Thrawn Trilogy, Talon Karrde defeats an enemy's attempt to steal his ship by holding down a switch on the control board and bluffing that it's a dead-man's switch controlling the ship's self-destruct mechanism. The switch actually just turns on the ship's headlights.
  • In The Hand of Thrawn, it's established that Thrawn had a clone in his secret base who would be released a period of time without Thrawn's intervention. Although, given the period of time that passes... he obviously didn't put a great deal of thought into the delay.
  • In the X-Wing Series novel Mercy Kill, a rather literal version is pulled by the Wraiths. They're currently besieged in an old observatory, with rescue inbound, but their leader has been killed. The Wraiths are unable to take the body along, but they also can't let the enemy know any of their identities, even of the deceased. The body is partially disguised, placed upright, and left out in the open for the enemy to find, while the Wraiths escape. Soon enough, Mooks find the body, but a single curious tap tips it over... triggering the pressure-sensitive explosives underneath, blowing up the entire installation.
• Star Trek: New Frontier:
  • The Redeemers place a special virus in their priests' blood. Should that priest be slain by anything other than natural causes, the virus goes airborne and obliterates all life on the planet it's on. In Dark Allies, they place a priest on a random world to blackmail the Excalibur into helping them fight the Black Mass...thus using a Dead Man Switch as a Dead Man Switch.
  • In Double Helix, the Big Bad knows the circumstances between Calhoun and his Dragon,^note Basically, Calhoun brings the guy's operation down around him and nearly kills him before the Big Bad rescued him but he also makes it abundantly clear that they're both on the same team now. (Calhoun is deep undercover again.) Thus, he tells them that should one of them die, he'll immediately assume the other did it and kill him.
• In Strega by Andrew Vachss, the police corner Burke and his outlaw friends in a subway tunnel. To give them time to escape, he throws a spare grenade pin in the direction of the police and claims to be holding the safety lever down, while sitting on an entire crate of grenades. After enough time has passed, he allows himself to be 'persuaded' to put the pin back in and drink the (drugged) coffee they're offering him.
• In a Superman Which Way game book, Lex Luthor uses one of these. He informs Superman that his computer equipment would shoot a deadly laser at Metropolis if it detected any physical injury inflicted on Luthor.
• Vorkosigan Saga:
  • In Cryoburn, a doctor who discovers a deadly secret about the cryo-preservation company he works for goes to outsiders for help, and is instructed to secure a copy of his information with a lawyer or a bank, to be released in the event that he dies or disappears or gets frozen. When the doctor gets caught by the company and dosed with Truth Serum, his savvy questioners get him to reveal where it is; however, he also reveals that two of the outsiders he talked to had taken copies of his information and made their own arrangements, giving the doctor's dead man switch some redundancy. And since the Corrupt Corporate Executives had, in the meantime, turned one of them into a Human Popsicle and killed the other one Deader than Dead...
  • Mark's brilliant business meeting in Mirror Dance. He had a valuable piece of merchandise — in this case, a code-ring worth billions of dollars, still on the original owner's hand — attached to a charge, while he held the dead-man switch and negotiated with the man's business rival/half-brother.
    Mark: Stun me or shoot me, and it will go off. Frighten me, and my finger might slip. Tire me out, and it might give way. Annoy me enough, and I might let go just for the hell of it.

Live-Action TV

• The Season 5 finale of Arrow has one of these as a major plot point. As part of his final gambit against Oliver, Prometheus kidnaps all his loved ones and drags them to Lian Yu, which he's rigged with enough explosives to completely destroy it, set to go off if he dies. As such, his plan to either kill Oliver in combat or goad Oliver into killing him (thus proving that Oliver's as big a monster as him) is guaranteed to kill Oliver either way. Prometheus later further goads him by threatening that either Oliver kills him to set the bombs off so his son William lives, or he doesn't and he snaps the boy's neck, killing him. Oliver takes a third option by only incapacitating Prometheus to save William, but Prometheus just kills himself, ending the season on a massive cliffhanger as the entire island explodes.
• Babylon 5:
  • Lennier saves the day by programming the White Star's computer to immediately leave the area (Z'ha'dum) if he doesn't touch a control every few minutes. Sure enough, a Shadow device starts screwing with everyone's mind, and the White Star is able to escape because he stops touching the control while under the influence.
  • In an earlier episode, a villain was threatening to blow up a station using one. The explosives were removed before the switch was released.
  • After gaining control of Edgars Industries, Garibaldi fires the Board of Directors and warns them that any further assassination attempts will trigger large bounties on each of their heads. In fact, the bounties will be triggered even if Garibaldi or his wife suffer accidental deaths, such as falling down the stairs, just for good measure.
• Blake's 7:
  • In "Deliverance", the Liberator is hijacked by a man desperate to get medical supplies to his father. When it looks like he's going to collapse from fatigue and his injuries, he rigs his Ray Gun so it will fire automatically if he loses consciousness. This is exactly what happens, but fortunately Blake shouts a warning and Cally rolls away in time.
    "I've put the energizer onto automatic. If I let it go, it will spring back and the gun will fire. If I pass out, the gun will fire by itself. Now you make certain that I don't go to sleep!"
  • In "Rescue", our heroes kill a villain and inherit his Elaborate Underground Base, only to find in the next episode that he'd set a nuclear implosion device to detonate if he hadn't sent a signal every 48 hours. No-one knows how long it's been ticking down either. And they can't get through the door to the hanger deck to escape.
• Blindspot: In "Any Wounded Thief", the heroes confront a corrupt general and find him in a building full of chemical weapons. He reveals he's wired the place with explosives, and warns that if his thumb comes off the detonator, the building will blow, releasing a multitude of deadly gases into the air that will likely wipe out the city. Jane manages to get close enough to simply snatch the detonator away, put her own thumb over the button lightning fast, beat up the general, then disassemble the detonator.
• The Boys (2019): In the season one finale, Billy Butcher puts Madelyn Stillwell (who has a Parental Substitute relationship with superhero Homelander) in an explosive vest set off by a radio detonator that will explode when he releases it. Unfortunately, his hostage proves useless because Homelander murders her instead. Butcher then sets off the detonator, but Homelander saves him as a Cruel Mercy.
• In the two-part season one finale of Burn Notice, Michael plants various C4 charges around a nightclub owned by a heroin dealer and uses a detonator with a Dead Man Switch to force the dealer into giving him the information he needs to rescue Sam.
• Criminal Minds: One episode has an unsub's henchman storm the police station wearing a suicide bomber vest with a dead man's switch so she can deliver the unsub's message. They deal with it by having JJ clamp down on her hand immediately after she's shot so she doesn't have time to release.
• Daredevil (2015): Leland Owlsley and Madame Gao conspire to have Wilson Fisk's girlfriend Vanessa poisoned in an attempt to get Fisk to focus on his crime business. When Fisk finds out and confronts Owlsley, Owlsley reveals that he has a switch: he's stashed away Carl Hoffman, one of the corrupt cops on Fisk's payroll. Owlsley checks in with him once every 24 hours and if Owlsley doesn't show, Hoffman will go to the FBI and rat on Fisk. The enraged Fisk kills Owlsley by throwing him down an elevator shaft, then sends the other corrupt cops in his pocket to search for Hoffman.
• Doctor Who: In "The Sound of Drums", reporter Vivien Rook sets a video message to automatically be sent to Torchwood if she dies confronting Harold Saxon, which Jack receives via his Vortex manipulator later.
• The Equalizer is protecting the ex-wife of a Corrupt Corporate Executive, whom McCall discovers has hired a man to kill her. McCall arranges for his Friend on the Force to put information in the police database that he is also a contract killer, then explains to the executive that if his ex dies of any cause, even natural ones, McCall will kill him.
• The Expanse: An accidental version in "Godspeed". The detonator on a bomb gets damaged, and the only way to stop it going off it to keep pressing the reset button. Unfortunately, this means that someone has to stay behind until it's time for the bomb to go off, as the reset time isn't long enough to push the button and get to a safe distance. In the following episode "Home", the bomb ends up being used this way for real, as Miller has to carry it right into the middle of the protomolecule which could easily assimilate him if his spacesuit got punctured. This leads to some tense moments when Miller almost doesn't hit the reset button in time.
• Farscape: near the end of the series, John walked into enemy territory to negotiate wearing a portable nuke with Dead Man Switches "from every culture on my ship and a few cultures I haven't heard of," that would activate if his heart stopped, sped up, or if he got "too hot, too cold, too happy, too sad, thirsty, hungry, bored..." The "too happy" was actually true, he had to tell his girlfriend not to stand too close to him because then the nuke would start beeping faster as his heartbeat sped up.
• The Flash (2014): In the Christmas Episode "Running to Stand Still", Captain Cold claims to have built one into his cold gun. It's left ambiguous whether he really has, but he's certainly Crazy-Prepared enough to do so, and Barry decides not to call his bluff.
• In the Haven episode "Chosen", Mara turns Duke Crocker into a "Trouble Bomb" and warns that he will activate if she is either killed or not allowed to return to her home dimension by the end of the day. Charlotte tries to get around this and end her threat by merging Mara back with Audrey Parker, with Audrey in control, but to everyone's horror, this apparently counts as killing her and Duke "detonates".
• Highlander:
  • In the third season two-part finale, Kalas got his hands on a CD-ROM disk that contained information on every known Immortal and Watcher. He has it rigged up to his computer so that if he does not return in a certain amount of time, the information on the disk will be sent to the media, telling the entire world about Immortals.
  • An episode from the last season had a man wearing a bomb vest that was wired to his heart rate so it would go off if he was killed. The female bounty hunter Immortal pursuing him got around it by shooting him in the head so his heart wouldn't stop right away, allowing her a few seconds to tackle him out the window and into the water below.
• Law & Order: The accidental activation of a fictional website similar to "You Were Left Behind" (see "Real Life" below), notifying those Left Behind that the Rapture has occurred, was the event that triggered the discovery of the body in the episode "Rapture".
• In Lost, the mercenary Keamy, the man who killed Ben's daughter Alex, has one of these connected to his heart, set to trigger a large explosive in the event of his death. Ben Linus doesn't care.
• Appears in the series 2 finale of Luther, where the villain holds a dead man's trigger attached to a suicide vest, and walks around London, untouchable. Averted when Luther convinces him to disable it under the ruse of a game and has him shot. At the end of the episode, Luther gets a female gangster who was blackmailing him to back down by saying that if anything happens to him or the woman he's protecting, a certain sociopath of his acquaintance will do something very nasty in response.
• An episode of Modern Family references the actual switch on trains when a mystery novel author with a focus on realism is frustrated by how all of his attempts to figure out how an engineer can cross a train unseen to commit murder are dashed by having the switch described to him.
• Motive: In "The Dead Hand", a woman wearing an explosive vest takes over the squadroom and hold Angie hostage. The bomb is linked to dead man's switch consisting of a heart rate monitor: if her heart stops, the bomb goes off.
• Nikita:
  • Percy has one set whereby, should he die, it will send a message to the Guardians of all of the black boxes to release all of the information on the boxes to the public. The boxes are hard drives containing all of the illicit operations of the United States government for a long time. Should that information be released, it would tip the balance of world power. Because of this, Team Nikita is currently working on plan Gotta Kill 'Em All before launching an assault on Division HQ.
  • Percy later uses another variation of the same system. If he dies, his henchman Roan will receive the signal to immediately start a nuclear meltdown in the middle of Washington DC. As a second layer of protection, if Percy does not phone Roan by a certain time, Roan will also start the meltdown since it will mean that Percy has been captured.
• In one episode of NUMB3RS, a federal fugitive who is essentially cornered takes refuge in a garbage dump full of explosive materials (It Makes Sense in Context) and activates a flare, knowing that if he is killed and it falls, the entire dump will blow up. Fortunately, Reeves is able to talk him down before anyone gets hurt.
• The Outer Limits (1995):
  • In "Dead Man's Switch", after an alien fleet is detected approaching Earth, a Doomsday Device is prepared by linking every nuclear, chemical and biological weapon in existence. Five people are placed in five bunkers around the world. When an alarm sounds, they have 30 seconds to hit a dead man's switch to disarm it. If none of the five do so in time, the doomsday device will detonate.
  • In "Final Exam", Seth Todtman has his 50-megaton cold fusion device rigged up so that it will detonate if his heart stops.
• The Professionals:
  • In "Old Dog with New Tricks", a nurse is taken hostage by a lunatic armed with a hand grenade with the pin removed. Bodie and Doyle make a reckless bid to free her because the longer he holds down the safety lever, the more cramped his hand will get.
    Doyle: The right technique is to keep him talking, play him and tire him out.
    Bodie: Yeah and suppose his left hand tires first? It takes about four pounds of pressure to keep a hand-grenade lever clamped down. But after an hour, it feels like eight... and then twelve... and then cramp sets in. And then suddenly it's raining Nurse Emma Bolding!
  • In "Lawson's Last Stand", the eponymous Colonel Lawson is holding up a cannister of nerve gas, strapped to a hand grenade with the pin wired to an overhead pole. He's standing out in the middle of a field wearing rear view mirrors so he can see if someone sneaks up on him, and has trained himself to hold up the weight of the cannister for one hour, by which time he wants his demands met or he'll drop it and kill millions.
• The Punisher (2017): Used three separate times. The first is by David Lieberman, who rigs his base with cameras that will send their feed directly to multiple news outlets if he doesn't input a code and complete a retinal scan every three hours — he does this so that if he is murdered, either by Frank or the various government agencies that are after him, the details of his death will be made public. The second is by Lewis Wilson, who uses a more traditional setup with an explosive vest when he attempts to assassinate Senator Stan Ori and takes Karen Page hostage. The third is by Lieberman again, using a modified version of his first setup, to blackmail the villains by making their actions public if they do not comply with his and Frank's demands. However, this one turns out to be a trick, as he had already given Homeland Security all of the information by the time Rawlins and Russo found out about the switch. He keeps the charade up to give him and Frank some leverage over the bad guys, who had taken his family hostage.
• In the final Quatermass series, the eponymous British scientist is not happy about his planned Moonbase being used to launch nuclear missiles for a proposed Dead Man deterrence strategy — the idea being that if an aggressor nuked Britain, missiles would launch from the Moon and wipe out the attacker three days later.
• In Robin Hood: The Sheriff of Nottingham has stated that if he dies an unnatural death, the entire county of Nottingham will be effectively destroyed by Prince John's forces. Recently, the system was accidentally activated when the Sheriff went sleepwalking and it was only shut down just in time.
• Smallville: In "Resurrection", Garrett straps a kryptonite bomb to his chest with his finger on the trigger and holds a hospital hostage. A deputy sniper kills him and his finger comes off the trigger, but Clark Kent manages to wrap the bomb in a lead apron and rush it away at super speed before it explodes.
• Sons of Anarchy: A variant with drug kingpin Damon Pope who, to ensure his own survival, has arranged a kill contract to be activated in the event of his death, offering a huge reward to whoever assassinates his killers. Jax gets around it by framing Clay Morrow for Pope's murder.
• In the pilot episode of Stargate Atlantis, the hero kills a Wraith Queen. As she dies, she tells him she and her underlings were not the only Wraith, but just the caretakers for other Wraith, and that when she dies, it will awaken all the Wraith. Once it happens, they see the pods holding the Wraith begin to come alive, and they discover that not only the Wraith on the planet, but all the Wraith in the galaxy had been awakened early from their periodical hibernation.
• Star Trek: Voyager: In "Scorpion", Voyager forms an Enemy Mine alliance with the Borg, who grant them passage across their territory in exchange for a weapon against Species 8472. To prevent the Borg from simply assimilating everyone, all information on the weapon is downloaded into their Emergency Medical Hologram, who promises to delete his own program at the first sign of trouble. "Well, maybe not the first sign..."
• In an episode of S.W.A.T. (1975), the boss of a bunch of crooks tries to escape by wiring himself to a bomb, with the switch in his hand. He demands and gets a truck, which he tries to escape in, driving one-handed. Naturally, something gets in his way, and he has to put both hands on the wheel — releasing the switch. Boom.
• In V (1983), Nathan Bates forces the Visitors to declare Los Angeles an open city with himself in charge, by revealing that his death will trigger the release of storage tanks of the Red Dust toxin that his company manufactures. He's bluffing as the toxin is fatal to humans (in the long term) as well as aliens.

Podcasts

• The Magnus Archives: According to Elias, if he is killed, everyone that works for the Institute will die, too. Melanie doesn't buy it for a second, and repeatedly tries to kill him.
• Lovelace has one of these in the second season of Wolf 359. If her heart stops or speeds up too much, a bomb on board her shuttle detonates, taking the Hephaestus with it. During "Who's There", she takes shrapnel to the stomach, resulting in heart failure on the operating table. While Hilbert manages to get her heart going again, the bomb still explodes, leaving Eiffel — who was in the shuttle at the time — stranded in deep space in a broken vessel for 180 days.

Radio

• Earthsearch. Before going into cryonic suspension on Challenger, Grand Emperor Thorden tells the Angel computers running the ship that he's brought his well-armed Killer Robot Fagor on board, and if he suffers a Cryonics Failure it will activate and destroy them. Unfortunately the Angels think he's bluffing, because Who Would Be Stupid Enough? to make a robot that can self-activate its weapon system? They turn off Thorden's life support and when the robot can no longer pick up his heartbeat, it proceeds to rampage through the ship looking for those responsible.

Tabletop Games

• Dungeons & Dragons:
  • The spell contingency is built for this trope. A wizard can set their death as the trigger for pretty much any spell they have in their collection... to the point that the Forgotten Realms have a special kind of The Undead, Blazing Bones, that is created when someone protected by death-contingency is killed by fire while casting a spell.
  • AD&D2 dragon magic of Forgotten Realms includes a death matrix spell. When a dragon "loaded" with it dies, it initiates a massive explosion loaded with scales, bones and dragonbreath. It's permanent and not dispellable.
  • D&D3.5 Complete Scoundrel introduces "Fatal Flame" — if the target dies before the spell expires, a mini-fireball explodes immediately, with the power dependent on Hit Dice.
  • Still 3.5, Spell Compendium includes the 5th-level "Death Throes" spell, which makes the caster explodes violently if he is killed. It's more powerful than "Fatal Flame", in fact much powerful than most damaging spells (since it has no level cap), but with the drawback that it can only be cast on the caster (and makes resurrection a lot harder when you've blown the body to bits).
• Exalted:
  • The Scarlet Empress ensured that the most ambitious of her children would not only not kill his siblings, but would be forced to be their protectors, by decreeing that he would be executed if they should die under any circumstances.
  • The Guild, the worldwide alliance of merchants largely made up of mortal humans, also has a favoured tactic of protecting themselves against gods and Exalted by setting up disasters to be enacted if they should die.
• In Magic: The Gathering, several cards give benefits to you or harm other players upon their removal from play. The most successful of these is Standstill, a card whose switch is a spell being cast. An entire deck archetype was built around it.
• Warhammer 40,000:
  • Due to the highly dangerous nature of the game's magicians (psykers), they are all shipped off to Terra where most of them are psychically fed to the Emperor and a few are trained to use their abilities for the Imperium. The places they're held at on their planets usually come equipped with a Dead Man Switch: If anything goes wrong, all the held psykers are instantly gassed. Considering what kind of trouble several hundred untrained and unsanctioned psykers can be, either on their own or as fodder for another entity, this can be considered justified.
  • Also, the Imperial Infantryman's Uplifting Primer recommends shooting any psyker seen without his "honor guard" of three other guardsmen (whose main purpose also entails shooting him if he happens to show signs of unusual behavior — like having a tentacle grow out of his chest).
  • Let's not forget the Penal Troopers, who are convicted criminals given one last chance to serve The Emperor. They get to charge the enemy wearing explosive collars, with a commissar holding the detonator. If the bomb doesn't go off, they are absolved of sin and free to go. Of course, they are also standing in front of a hostile army, unarmed.
  • The new Space Wolves Hero Unit, Lukas The Trickster, has one of his hearts (ripped out by a Dark Eldar pirate, he survived) replaced with a stasis bomb — if he's ever killed, everyone around him (probably including his killer) will be trapped in stasis for eternity with his laughter.

Video Games

• In Batman: Arkham Knight, some of the Arkham Knight's soldiers exploit Batman's Thou Shalt Not Kill methods by wearing suicide vests programmed to explode and kill the wearer should they fall unconscious, and making damn sure Batman knows it, thus protecting themselves from being on the wrong end of a Bat-beatdown. Being that the Arkham Knight is Jason Todd, who wants Batman to throw his code against killing to the winds, this is quite intentional.
• A bug in Call of Duty: Modern Warfare 2 allowed for a similar situation... with a Javelin guided-missile launcher. Whenever someone using the glitch died, their missile would launch straight into the ground, killing everyone within 20 feet unless they had a specific combination of perks and equipment to reduce damage from explosions.
• Command & Conquer: Red Alert 3: After President Ackerman goes rogue and activates the intercontinental laser targeting the USSR in Rushmore Roosevelt's head, he announces that there's a system tied to his heart that is set to fire the laser if his heart stops beating, meaning you can't just target his limo to end the level (as it will fire when the limo reaches the firebase controlling the laser). It also leads to a Kaizo Trap if a clever player think to use a Cryocopter to freeze the limo in place: the AI regularly spawns fighter jets precisely to prevent this, and as the jets position themselves over the limo it's entirely possible for a jet to die and the wreckage to fall squarely on the limo, destroying it and failing the level.
• In Fallout: New Vegas: Dead Money, the death of any one character will cause a timed detonation of the others' bomb collars, including yours, except inside the casino, where it can only trigger yours while you're on the same floor as them. At the end, once you kill Elijah or he traps himself in the vault, it also triggers your detonation timer, and you only have about a minute to escape the basement before your head explodes.
• Final Fantasy:
  • The "Auto-" spells and effect materia in various Final Fantasy games and inspired series work much the same way as Contingency in Dungeons and Dragons (useful when the Dead Man's Trigger is set to bring the operator Back from the Dead).
  • Final Fantasy VI has the Optional Boss at the top of the Fanatic's Tower. If you manage to survive the incredibly lengthy staircase gauntlet (with no save points), and beat the boss, he'll cast Ultima before dying, killing the party. Fortunately, it was the game that introduced the Auto-Life spell to the series, which is the only way to win without excessive grinding or taking forever to drain the boss's MP to zero. He's far from the only one, too; the game has many bosses and Elite Mooks that have some kind of desperation attack they'll perform right before they die, in an attempt to take someone with him.
  • In Final Fantasy VII, the Final Attack materia is a linking materia to set up a spell or action when the character is killed. Linking either Revive or Phoenix to it pretty much guarantees immortality, as long as you have a way to keep your MP up (MP Absorb + Knights of the Round or Master Summon is a good idea). The number of uses is limited by the materia's level (at most 5), though.
• The Rebel Flagship in FTL: Faster Than Light has an AI that will take over take over the ship if all its crew gets killed, repairing its systems.
• In Half-Life 2, whenever a Civil Protection Officer is killed, his radio emits a loud audible screech, followed by a female voice giving information on the location and officer's status, and ordering other nearby officers to respond.
• Hitman:
  • An early mission in Hitman: Contracts has you targeting a man in possession of nuclear explosives who is also the target of a SWAT Team; shortly after they storm the ship he's holed up in, he activates one of these to force them to comply with his demands.
  • In Hitman (2016), the plot of the Patient Zero campaign starts with one of these. The first mission is a routine contract, murdering the founder and second-in-command of an Apocalypse Cult. However, the founder's death trigger's a dead man's switch that sends orders to all the cult's operatives throughout the world to begin a global bioterrorism plot to bring about The End of the World as We Know It, resulting in the following three missions to foil said plot.
• Horizon Forbidden West: It's revealed that Ted Faro put a deadman switch on his reactor, so that if any of the other survivors he dragged with him ever killed him, they'd shortly after die too. By the time of the game, the reactor is still going strong because Faro managed to survive as a hideously mutated immortal blob, clinging to the reactor. When the Ceo (who had worshiped Faro as a god until that moment) see it, he orders it destroyed, which promptly causes the reactor to melt down.
• Big Bad Clement uses one of these in the finale of The House of the Dead: OVERKILL. He uses a remote switch that will blow up the surrounding area, explicitly calling it the trope's title. However, he soon hands it over after revealing he wants to redeem his evil ways, not minding when Isaac Washington claims he's chucking it out the nearest window as soon as he and Agent G are out of the blast radius (which he indeed does once they're in a helicopter).
• In Invisible, Inc., guards are equipped with heart monitors which raise the alarm when the individual is killed.
• In Marathon, if a player has his fusion pistol charged when he is killed, it will discharge its blast, possibly killing from beyond the grave.
• The first four Robot Masters you fight in Mega Man 7 were activated by a Dead Man Switch a couple months after Dr. Wily was sent to prison at the end of the last game.
• Metal Gear:
  • Metal Gear Solid 2: Sons of Liberty:
    • The Patriots are holding Olga's child hostage, and if Raiden ends up dying before completing the mission, they'll kill her too. They claim that Rose is in the same dilemma, but given the circumstances of that ending, nobody's can really be sure if that's actually the case.
    • Inverted in the case of the nuclear strike; the President needs to both be alive and input his code of his own free will (meaning no coercion or drugs or the like) in order to activate it, and if he fails to willingly reconfirm every hour, if his vital signs don't line up right or if he gets killed, the launch sequence will be nullified (specifically, launch authority will shift to the Vice President, ending the nuclear threat because he's not among the bad guys' hostages). It sadly doesn't stop Dead Cell from preparing a purified hydrogen bomb once Ocelot assassinates the President, though.
  • The various members of the Quirky Miniboss Squad in Metal Gear Solid 3: Snake Eater appear to have switches that blow up their bodies upon their deaths, presumably to prevent Snake or other enemies from capturing them alive or acquiring any intelligence from their remains, with Snake also believing that they're fully prepared to die. The Fear's and The Fury's switches also come close to being a Taking You with Me, as the former results in shooting out dozens of poisoned crossbow bolts, while the latter turns into a giant human-faced fireball that chases Snake down.
  • In Metal Gear Solid: Peace Walker, the eponymous Peace Walker is this for the US government; a mobile nuclear launch platform with a top-of-the-line AI capable of launching on its own initiative if the chain of command is out of touch. The main villain, Hot Coldman, takes advantage of this by programming Peace Walker to launch a nuclear attack mere seconds before he dies of his wounds, leaving everyone else unable to stop it in any way other than destroying the mech itself.
• In Mission: Impossible (Infogrames), if any of the mooks on the train alert MAX to Ethan's presence, she will immediately detonate the bombs, taking him with her.
• Security guards in PAYDAY 2 carry pagers that activate when they are killed or taken hostage. Up to four can be answered during a heist — answering a fifth (or failing to answer within the 12-second time limit) will set off the alarm. The guy on the other end will warn you of this once you've answered four pagers, however.
• Pagers return in PAYDAY 3, and are a bit more merciful — failing to answer in time will count as two answered pagers, and answering too many will trigger a search under normal circumstances, only raising the alarm if a search is already active.
• The Aftermath ability in Pokémon (called Detonate in Japan) does damage to the opponent equal to one-quarter its max HP when the Pokémon bearing the ability is knocked out. The Destiny Bond attack has a similar effect except that it KOs the opponent when the user is defeated if they don't switch out.
• In the final mission of Rainbow Six: Rogue Spear, Kutkin radios his Mooks every two minutes. If you kill any of them before taking him down, he will trigger the nuclear meltdown.
• The first campaign of Shadowrun Returns is called Dead Man's Switch, for good reason: The plot starts when the victim of a serial killer contacts the player through one of these.
• In Silent Scope, if you miss the final bullet or hit the Big Bad anywhere other than the head, he detonates the bomb and kills the President.
• Splinter Cell:
  • This trope is the crux of the plot of Pandora Tomorrow; the Big Bad radios certain people once a day to give them the code phrase "Pandora Tomorrow" to delay his plan to strike America by a day, requiring the player and their allies to remove the smallpox-carrying bombs that would be the first strike before the player can take out the bad guy. In a meta-sense, this sort of thinking is also why they specifically capture him rather than just assassinate him like they did with the big bad of the first game, Lambert specifically claiming that dead leaders tend to be "stubborn ghosts".
  • The prologue mission in Double Agent has a similar situation, where the commander of the facility you're infiltrating, once he realizes what's going on, ignites a flare and threatens to drop it into a vat of gasoline. Where it kind of falls flat is that if you shoot him or get spotted by him, he drops it and blows the place up, but if you sneak up and grab him... it still falls through the catwalk and into the gas, but doesn't ignite it for some reason.
• Syphon Filter: In the first game, killing Girdeux with explosives will set off the virus bomb. In the second, shooting Morgan before the bombs are defused will blow up the expo center.
• Star Wars: The Old Republic: After Keeper disobeys the Dark Council one too many times, they threaten him with execution. Keeper, who has been a part of Imperial Intelligence for many years and is privy to most, if not all, of the Empire's dirty little secrets, implied that certain documents would be released in the event of his death. The Dark Council was forced to grant Keeper early retirement.
• The Hijacking mission in Target Terror has the pilot held hostage by a terrorist with a Dead Man Switch that will trigger a bomb if you kill him. Shoot the remote to disable it. The painful thing of this is that the hijacking mission is the last mission in the game to complete and it's supposed to be the hardest where the terrorist holding the pilot hostage is supposed to be the boss.
• In Trials of Mana, Belladonna places a Choker of Death on Hawkeye's Love Interest Jessica. If Belladonna dies, the Choker of Death will kill Jessica in return, leaving Hawkeye unable to just gut the witch like he wants. It apparently also works in reverse, as Belladonna has the choker removed before she attempts to sacrifice Jessica to the Firestone.
• World of Warcraft:
  • When adventurers kill the corrupted Titan Watcher Loken, he utters in his dying breath, "My death... heralds the end of this world." Loken was tasked by the Pantheon to imprison the Old God Yogg-Saron, and an "Algalon fail-safe" mechanism put in place to trigger if Loken met his demise. Unfortunately, the Titans didn't factor in the possibility of Loken's corruption by the whispers of the Old God that he was imprisoning. Hence, in the Ulduar raid instance, adventurers must "convince" Algalon that all is normal.
  • Subsequently, in Icecrown Citadel, the spirit of Uther the Lightbringer warns Lady Jaina/Lady Sylvanas and adventurers that there must always be a Lich King, and that if the Lich King was destroyed without a successor, resulting in loss of control over the Scourge, the undead would overrun Azeroth like locusts.
• X-COM: UFO Defense:
  • Soldiers can prime a grenade or a bundle of TNT to explode when they collapse.
  • Fallen "Cyberdisk" units have a habit of blowing up (and taking out entire buildings with them). It requires some effort to kill them in such a way that they won't explode and thus leave Cyberdisc remnants for research.

Visual Novels

• Danganronpa: Trigger Happy Havoc: Junko invokes this to pressure the remaining survivors into succumbing to despair and hide in the school forever.
  Junko: Oh, that's right! I almost forgot! The outside world is barely habitable. What keeps us safe here is tthe air purifier purring away in the physics lab. I'm isometrically linked to it, so if I die, that's all she wrote~!

Webcomics

• In Ask Dr Eldritch, the titular hero brings one on a mission to rescue his house troll.
• One Bug Martini strip has Bug plan to do this for his Twitter account, so it displays a dignified death message instead of leaving his last tweet to be about something like his farting problem.
• In this Casey and Andy strip, it's revealed that Lord Milligan has explosives in his base triggered on his own heart stopping. He is a traditional villain, after all.
• In General Protection Fault, Nega-Ki faces off against Ki's group as they're raiding the palace, telling them that she has a dead man's switch to flood the hallway with poison gas. Ki tells her counterpart that she's willing to die to save Nick, but questions whether her counterpart is willing to die to fulfill Nega-Nick's evil plans. Nega-Ki backs down, but moments later, soldiers arrive to capture Ki's group.
• Genocide Man: Each of the Genocide Agents does their work with a backpack-sized bioweapon lab that's programmed to release an extraordinarily virulent plague if the equipment is stolen or the Agent is killed. One Agent's suicide took 250 000 people with him and evacuated Washington State because diving into fresh concrete wasn't quite enough to stop it. Joey doesn't have one anymore, however, because he kept setting it off on purpose for a quick laugh and got hundreds of thousands of people killed in the process.
• As seen above, in Girl Genius, a member of the disorganized swarm of assassins attempting to kill reluctant tyrant Klaus Wulfenbach carries one of these, although it proves less effective than he'd hoped.
• Homestuck: If Snowman dies, the entire Alternian universe goes down with her. Initially it stops Spades Slick from even risking hitting her, but after Doc Scratch forces his hand he goes through with it.
• Schlock Mercenary: The ridiculously massive and powerful Eldritch Abominations known as Paa'nuri do this with entire stars. They use gravity control to grab a massive planet and throw it at something, while forcefully increasing its density until it initiates fusion and becomes a star. So now there's a planet-sized flaming projectile flying at whatever the Paa'nuri doesn't like. If the Paa'nuri is killed, the gravity knot at the center of the new star unravels, and since the star isn't massive enough to sustain fusion naturally, it explodes. Shielded warships can handle a supernova without too much trouble (or just escape), but since these fights happen in heavily populated systems, the defenders are left trying to evacuate entire planets before the blast wave reaches them.

Websites

• SCP Foundation: The SCP-712 ("The Impossible Colors") apparatus has a fail-secure system installed in it. If the researcher viewing the Fictional Color is incapacitated and releases pressure on a thumb switch, their view of the color will be blocked by a light-absorbing panel.

Western Animation

• In the Batman Beyond episode "Final Cut", the last surviving member of the Society of Assassins blackmails Batman into protecting him from the villain who has wiped out the rest of the League by hiding a bomb in Gotham City, programmed to go off if he does not enter the proper code every twelve hours. It doesn't do him much good.
• In the Batman: The Animated Series episode "Fear of Victory", when confronted by Batman in the stadium rafters, Scarecrow holds a vial of potent fear toxin over the side. If Batman attacks in any way, he will drop the vial and drive the entire audience below into a violent, panic-induced frenzy. Robin is able to catch the vial afer Scarecrow drops it.
• Miraculous Ladybug: In "Startrain", Max's mom, a train conductor, shows off the actual dead man's switch when the class takes a fieldtrip on her train. She's shown holding it later, even using her nose to check for emails on her smartwatch to avoid releasing it. It becomes the akumatized object when her anxiety over potentially being rejected from the astronaut program gets the better of her.
• My Little Pony: Friendship Is Magic:
  • In "The Crystal Empire - Part 1", King Sombra's Establishing Character Moment in Celestia's flashback involves a magical equivalent: after she and Luna banished him, his backup curse warped the Crystal Empire through time until his return, thus rendering their victory pyrrhic at best.
  • The threat in "Princess Twilight Sparkle - Part 1/Part 2" turns out to be a failed attempt at this. Back when Discord was first defeated by Celestia and Luna, he spread seeds that would grow into vines that would destroy Equestria, just seconds before being turned to stone. However, they didn't do so for another 1,000 years, well after not just his second attempt at conquering the land, but also after his later Heel–Face Turn. Given that he's Discord, he doesn't explain this until after the day has been saved.
• In Star vs. the Forces of Evil, Queen Moon's deal with Queen Eclipsa essentially turns Toffee into a living Dead Man's Switch. When he dies, she fulfills her side of their Magically-Binding Contract and is freed from her Crystal Prison, and dealing with the fall-out from her release takes up much of the plot of the rest of season 3.
• Star Wars: The Clone Wars: In "Hunt for Ziro", Ziro the Hutt reveals that he has a holodiary filled with incriminating evidence against the Five Hutt Families, information that will be transmitted to the Republic should he face an untimely end. He later breaks out of jail with help from his ex-girlfriend Sy Snootles to recover the diary and move it to a safer location, but unfortunately for Ziro Snootles is on Jabba's payroll and very pissed off that Ziro abandoned her in the past, murdering Ziro and turning the diary over to Jabba once she gets her hands on it.
• In The Transformers, Starscream gains control of the Combaticons by adjusting them so that only Starscream can recharge them. Thus, if they betray or abandon him, they will doom themselves. Eventually, they manage to disable that feature, gaining their freedom.
• Brock Samson uses this as a security measure in The Venture Bros. when he has surgery to remove H.E.L.P.er's head, stuck in his chest like giant annoying shrapnel after the explosive finale of season 3. He nonchalantly pulls the pin on a frag grenade, and sticks it in H.E.L.P.er's mouth. He didn't trust his Argentinian Back-Alley Doctor.
• Young Justice (2010): The villains have captured several heroes during an attack on Mount Justice, and Blue Beetle is trying to stop them, when Aqualad threatens to detonate a bomb powerful enough to destroy the entire mountain, and says he will disarm it only if Beetle surrenders. Beetle is tough enough to survive it, but stands down to not risk killing the other heroes, much to the protest of his Scarab, who doesn't care about them and is convinced that it's a bluff. The Scarab briefly takes control and attacks Aqualad, causing his finger to come off the switch... and nothing happens, as it really was a bluff.

Real Life

• British missile submarines had (and may still have) the "bolt-from-the-blue" procedure, in case Britain is destroyed by a surprise nuclear attack. This is referenced in the VX episode of Spooks: when each new Prime Minister enters office, he or she writes letters to the captains of the four Vanguard-class submarines, which are placed unopened in the safe (once the PM leaves, the letters are destroyed unread.) If the submarines lose contact with London, they perform a considerable number of checks (including checking whether they can still pick up the Today radio programme on longwave). Once they are convinced that Britain is no longer there, they open the safe. There appear to be (according to the Peter Hennessey book The Secret State, the source for this) four things that can be in there:
  • Go to Australia, if it's still there.
  • Put yourself under American command, if the US is still there.
  • Nuke Moscow or whoever actually launched the attack.
  • Use your own judgment.
• In some Pennsylvania prisons, guards are equipped with a distress radio that will call in reinforcements if they pull a rip-cord buttoned to their shirt, or if their torso tilts by more than 45°. Thus, if they get into a fight with an inmate and are incapacitated, the distress signal automatically alerts the entire facility.
  • Wisconsin prisons have phones that activate alarms if they are left off the hook for 30 seconds.
  • Firefighters wear something similar called a PASS Device (Personal Alert Safety System), also called a DSU (Distress Signal Unit). If the firefighter stops moving, it emits a loud siren to alert another firefighter.
    • In North America this device is incorporated into the firefighter's breathing apparatus and the motion sensor activated when the air supply is turned on. That way, users cannot fail to arm the device in hazardous environments.
• Perimetr. A largely, though not entirely, automated "Dead Hand" system which was created as a Soviet nuclear-control system. It's generally speculated to function by use of elaborate, unmanned sensors that track pressure, light, and radiation throughout the country, but must be armed first (hence not being fully automated), which is done so in times of crisis. It's believed that it was created to give the Soviet leadership a way out of being compelled to launch a first strike—even if the entire leadership was annihilated by an American first strike, they could rest assured that Perimetr would retaliate, thereby absolving them of that responsibility (an attractive premise, especially to the aging Kremlin leadership of the late 1970s and early 1980s).
  • One possible explanation for a mysterious radio signal known as UVB-76, or just "The Buzzer" is that it's related to Perimetr in some way: If it suddenly ceases to transmit, and no coded voice message is heard within a certain period confirming that it was a false alarm, the Russian military will go to the local equivalent of DEFCON 2 or higher.
  • Israel's Project Samson plan can be set to work similarly, meaning that once the nuclear devices are armed even if the entire government is killed at once they will still go off. That being said, the government could decide not to use it, depending on the nature of the threat.
  • The Swiss Alps are rigged to blow up with a Dead Hand, should the country ever be invaded. Though there's little reason for anyone to bother. Still, were this ever to happen the dirt and rock blown into the atmosphere would plunge the world into darkness for days and likely cause crops to fail worldwide. Also not a true Dead Man's Switch, as it does have to be armed by the Swiss military first.
• A website called "You Were Left Behind" sells itself as a service for devout born again Christians who are worried about being taken up into heaven during the Rapture, and want to leave messages for friends and loved ones just in case it happens during their lifetime. The site works (or claims to work) by having a small inner circle of administrators who have to log in at least once every three days. If all of these brave Christian soldiers miss two updates in a row at the same time, then the Rapture must have happened and all the clients' messages will be delivered.
• A similar all-purpose site exists, fittingly enough called Dead Man's Switch.
• During the Beslan terrorist attack in Russia in 2004, the men set up dead man's switches so that if the terrorist were gassed, the bombs they set up would still go off.
• One group of people tried to escape from East Germany by running a checkpoint in a truck. Loaded with dozens of propane tanks on the bed. As expected, none of the guards shot at the truck or tried anything to make it crash and instead just ran out of its path and let it pass through unchallenged.
  • Partially subverted, the propane tanks were empty, so shooting them would have done nothing. Of course, the guards didn't know that.
• Some smaller boats, such as RHIBs (Rigid Hull Inflatable Boat), have dead man cords which are connected to the boat's batteries and the helmsman. Should the helmsman fall overboard, the deadman will detach from the boat and shut down the engines. The same goes for jetskis; when you're out in open water, you certainly wouldn't want your jetski to go zooming off without you on it.
• This is the principle of the safety key in most exercise machines, especially treadmills. It's nothing but a magnet attached to a piece of cord that has a clamp on its end for the user to stick to their clothes; the magnet is vital for the circuitry to work, and if it's pulled off (either by the user falling down or distractedly walking away from the machine, the two most common scenarios), the equipment instantly shuts down.
• Websites that you log into that contain sensitive information or are expected to be accessed on public machines will often automatically log out after a period of inactivity to prevent someone from doing something with that account, either by accident or with ill intent.
• North Korea has a massive number of Cold War era artillery cannons aimed at Seoul in the event a war breaks out or the ruler is killed. The amount of artillery is enough to completely destroy Seoul, the 9th largest city in the world with a population of 23+ million. Of course, the South Koreans and their allies could do much worse to North Korea if it were to attack first, so it goes both ways.
• According to some sources, spies who were to be dropped into Nazi-occupied Europe were guarded by British soldiers who carried grenades with the pin removed so they wouldn't sleep on duty. Even assuming this happened, it's hard to believe a soldier in that circumstance wouldn't just tie down the lever or 'acquire' a replacement pin.
• Modern locomotives often have a "Dead Man's Pedal" in the cab, which is, as the name suggests, a foot pedal on the floor of the locomotive that must remain pressed for the locomotive to operate. Should it be released for any reason (such as in the case of the engineer becoming incapacitated) it will automatically shut down the engine and apply brakes, hopefully bringing the train to a stop before it hits something. Another version is a handle that must be briefly released every thirty seconds or so, stopping the train if it's held down by a dead body. Since it is possible that an incapacitated driver could slump over and hold the pedal down and drivers have been known to deliberately subvert the dead man's pedal by placing a heavy object on top of it, another version incorporates a 'vigilance button', that beeps at random intervals and, if not pressed within a couple seconds, activates the brakes.
• Most braking systems found on trains and semi-trailers also function on a form of Dead Man's Switch, by virtue of the pneumatic pressure being used to release the brakes rather than apply them; if the trailer becomes disconnected from the cab or locomotive, the loss of pressure that holds the brakes open will automatically apply, stopping the trailer/train car from freely rolling out of control.
• In information security this is a pretty common type of logic bomb (not that Logic Bomb). At least it's commonly discussed in cyber-security courses. A typical scenario goes like this: Bob the sysadmin gets wind that he might be next in a round of layoffs. He writes a little script that checks Active Directory every day to see if his name comes up. If his name doesn't come up, it assumes he's been let go and retaliates by deleting all important backups, or any number of other destructive things.
  • Of course, this only works if the script is run by an account with sufficient privileges, which is one reason that sysadmin best practices often discourage the use of "system accounts" (accounts not tied to a specific user) when not absolutely necessary. Bob would thus need to find a way to get the script into a different account he could control somehow once his had been removed. Assuming HR remembered to make sure his account was actually disabled once he was let go, of course.
• Watchdog timers are used in embedded systems to reset the processor (or at least raise a non-maskable interrupt) if it gets stuck in a loop and fails to clear the timer before it times out. Many older Arcade Games implemented watchdog timers by using a simple logic circuit to increment a counter once every frame, with the last counting stage or carry output asserting the master reset signal. The Neo Geo MVS included a watchdog timer, but the AES home console did not, and many game cartridges exploited this to distinguish between the two systems during the boot sequence. Watchdog timers have also been integrated into numerous microcontrollers, many of which make the timeout interval programmable and/or require a specific sequence of magic numbers to be written to a certain register within a few machine cycles in order to clear the timer (to make it harder for a malfunctioning piece of code to do this accidentally).
• This is at the heart of the internet’s self-healing ability. Routers will send packets to their immediate neighbors letting them know that the routing protocol is running properly and the communication medium between the two routers is in order. Should a line get cut or a router go offline, the effected router’s neighbors will notice the lack of communication and let the rest of the network know. Packets will then be rerouted through another path, ensuring an uninterrupted flow of cute cat videos.
• Ervil LeBaron, leader of Mormon fundamentalist group Church of the Lamb of God, had rival fundamentalists or dissenters murdered as "blood atonement." Shortly before he died in 1981 while serving a term for murder, he had published and smuggled out of prison a list of around twenty persons he wished to see dead. In 1988, several of those on this list were murdered, simultaneously yet separated by several kilometers, by his disciples acting on his posthumous orders.
• Opera GX (a gaming-oriented spinoff of the Opera web browser) has an option called "Fake My History" that automatically erases your browsing history if you don't use the browser for 14 days ("we'll assume you're dead, or using a different browser"), and additionally replaces said history with a sanitized fake history.
  "Think volunteer work, single-source chocolate and composting at home – a rose-tinted redux of your web life, even if it is a little… embellished. As in the browse, so in the after-browse."

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