History UnwittingInstigatorOfDoom / LiveActionTV

* Narrowly {{averted}} by Princess Mithian on ''Series/{{Merlin|2008}}'', who, in a bid to impress Myth/KingArthur, shoots a young deer in the forest. Unbeknownst to her, the deer is actually [[BalefulPolymorph Guinevere under an enchantment]]. Only Merlin realizes what she's done and returns to the forest at night to hunt for Gwen and heal her from her injury.

* In the second season of ''Series/CriminalMinds'', [[spoiler:the team was trying to bring in a delusional war veteran who is panicking because the construction sounds like the war zone. Now, they find him and have SWAT surround the suspect as they coax him to surrender. They tell these construction men nearby in plain view of the drama to stop working until they are done, but naturally the men resume construction before the suspect is apprehended. This causes the suspect to panic and he runs towards a kid on a bike, forcing a SWAT marksman to fatally shoot him.]]

* A particularly heartbreaking episode of ''Series/ColdCase'' gave us a girl who had a crush on the VictimOfTheWeek, who was a mentally-challenged teenager. One day alone in class, she tried to kiss him when her [[BastardBoyfriend meathead boyfriend]] walked in and she lied and said ''he'' tried to sexually assault ''her'' so that she wouldn't get a "bad reputation", which essentially caused him to be beaten up by the said boyfriend and his gang of thugs (as well as his only friend, who was embarrassed by him), her parents deciding to file charges against him, him ending up in an institute instead where, due to his alleged sexual deviance, is in the worst tier of the facility where the care for the patients is horrifyingly neglectful, quite frankly. In addition to this, the boy's loving mother (and one of only two people at this point who gave a damn about him) is dying of cancer as all of this is occurring, the boy's [[JerkAss father won't take care of him because of his mental status]] and the boy's [[spoiler:caregiver, who was also dating the mother, takes him from the institute and [[TearJerker rather than have him live a life of loneliness and neglect, has him run over by a train.]]]] In present day, the girl FINALLY realizes the effect of her actions and is remorseful, but it's still too little, ''way'' too late.

** Julia is pretending to be her dead twin sister Sara half to hide from the PoliceState, half because her brother-in-law Hugo needs Sara to be alive to keep a job. The police eventually takes Julia in for interrogation as Sara, and Hugo insists on going with her. This happens while Hugo and Julia's employer Luis is visiting Julia's mother. With Hugo away, Luis is driven home by Hugo's brother Álex. By that point, Álex has met a few members of LaResistance, including a RichKidSocialActivist who lives in the same area of town as Luis. Of course, Álex being Luis' driver instead of Hugo results in him finding out who the resistance member is in real life.

* ''{{Series/Legion|2017}}'': Charles Xavier inadvertently sets in motion a chain of events which would gradually lead to his son David's descent into supervillainy. Charles travels to Morocco to meet Amahl Farouk, who turns out to be a malevolent entity, so they engage in a BattleInTheCenterOfTheMind. Charles defeats Farouk by pushing the latter's consciousness out of his body, but Charles fails to kill his opponent. A formless Farouk then finds his way into baby David's mind, latching on to it like a parasite. Charles is unaware that Farouk had already infected David's psyche, and fearful of what a vengeful Farouk might do to his infant son, Charles gives David up for adoption, believing that Farouk will not be able to find him (and thus keep David safe). Farouk then poisons David's mind for decades, and the latter becomes increasingly unstable as he gets older, with little to no control over his vast array of mutant powers. To make a long story short, insanity and winning the SuperpowerLottery are a terribly destructive combination, and David can bring about the end of the world. All of this could've been avoided if Charles had simply remained at home, caring for his wife and son.

* ''{{Series/Legion|2017}}'': Charles Xavier inadvertently sets in motion a chain of events which would gradually lead to his son David's descent into supervillainy. Charles travels to Morocco to meet Amahl Farouk, who turned out to be a malevolent entity, so they engage in a BattleInTheCenterOfTheMind. Charles defeats Farouk by pushing the latter's consciousness out of his body, but Charles fails to kill his opponent. A formless Farouk then finds his way into baby David's mind, latching on to it like a parasite. Charles is unaware that Farouk had already infected David's psyche, and fearful of what a vengeful Farouk might do to his infant son, Charles gives David up for adoption, believing that Farouk will not be able to find him (and thus keep David safe). Farouk then poisons David's mind for decades, and the latter becomes increasingly unstable as he gets older, with little to no control over his vast array of mutant powers. To make a long story short, insanity and winning the SuperpowerLottery are a terribly destructive combination, and David can bring about the end of the world. All of this could've been avoided if Charles had simply remained at home, caring for his wife and son.

* ''{{Series/Legion|2017}}'': Charles Xavier inadvertently sets in motion a chain of events which would gradually lead to his son David's descent into supervillainy. Charles travels to Morocco to meet Amahl Farouk, who turned out to be a malevolent entity, so they engage in a BattleInTheCenterOfTheMind. Charles defeats Farouk by pushing the latter's "essence" out of his body, but Charles fails to kill his opponent. A formless Farouk then finds his way into baby David's mind, latching on to it like a parasite. Charles is unaware that Farouk had already infected David's psyche, and fearful of what a vengeful Farouk might do to his infant son, Charles gives David up for adoption, believing that Farouk will not be able to find him (and thus keep David safe). Farouk then poisons David's mind for decades, and the latter becomes increasingly unstable as he gets older, with little to no control over his vast array of mutant powers. To make a long story short, insanity and winning the SuperpowerLottery are a terribly destructive combination, and David can bring about the end of the world. All of this could've been avoided if Charles had simply remained at home, caring for his wife and son.

* ''{{Series/Legion|2017}}'': Charles Xavier inadvertently set in motion a chain of events which would gradually lead to his son David's descent into supervillainy. Charles travels to Morocco to meet Amahl Farouk, who turned out to be a malevolent entity, so they engage in a BattleInTheCenterOfTheMind. Charles defeats Farouk by pushing the latter's "essence" out of his body, but Charles fails to kill his opponent. A formless Farouk then finds his way into baby David's mind, latching on to it like a parasite. Charles is unaware that Farouk had already infected David's psyche, and fearful of what a vengeful Farouk might do to his infant son, Charles gives David up for adoption, believing that Farouk will not be able to find him (and thus keep David safe). Farouk then poisons David's mind for decades, and the latter becomes increasingly unstable as he gets older, with little to no control over his vast array of mutant powers. To make a long story short, insanity and winning the SuperpowerLottery is a terribly destructive combination, and David can bring about the end of the world. All of this could've been avoided if Charles had simply remained at home, caring for his wife and son.

* ''Series/ControlZ'': It turns out that [[spoiler:Sofia]] actually gave the hacker the idea for exposing everyone's secrets with a comment she'd made.
* In the second season of ''Series/CriminalMinds'', [[spoiler:the team was trying to bring in a delusional war veteran who is panicking because the construction sounds like the war zone. Now, they find him and have swat surround the suspect as they coaxed him to surrender. They tell these construction men nearby in plain view of the drama to stop working until they are done, but naturally the men resume construction before the suspect is apprehended. This causes the suspect to panic and he runs towards a kid on a bike, forcing a SWAT marksman to fatally shoot him.]]

* In ''Series/QuincyME'' episode "Tissue of Truth", a kidnapper abducts a boy and [[BuriedAlive buries him]] somewhere, promising to give the location after his ransom demand is met. Monahan and the police plan to find and follow him after the RansomDrop, but unfortunately, [[SpannerInTheWorks a local sheriff]] overhears what's going on over the police band and chases after the kidnapper's car, causing the guy to get into an accident and die. Since he was the only one who knew where the boy was buried, Quincy and the others are forced into a RaceAgainstTheClock to find him before his oxygen runs out, relying only one GPSEvidence.

* In the second season of ''Series/CriminalMinds'', [[spoiler:the team was trying to bring in a delusional war veteran who is panicking because the construction sounds like the war zone. Now, they find him and have swat surround the suspect as they coaxed him to surrender. They tell these construction men nearby in plain view of the drama to stop working until they are done, but naturally the men resume construction before the suspect is apprehended. This causes the suspect to panic and he runs towards a kid on a bike, forcing a SWAT marksman to shoot him.]]

* Hilariously and perfectly summed up in the ''Series/MarriedWithChildren'' episode "976-SHOE" where Marcy yells at Steve for his [[WhatAnIdiot boneheaded]] decision to loan Al $50,000 from his bank for an unsuccessful shoe hotline to win an office sweepstakes contest to Hawaii:

** This also happens in ''Series/KamenRiderGaim'' in the form of [[spoiler:Mai Takatsukasa as the Woman of the Beginning. After being turned into an Overlord, she attempts to use her newfound powers to travel back into the past befor everything went to hell in order to convince Kouta, Mitsuzane, and Kaito to abandon the battle. Unfortunately, because she didn't know how to use her powers properly she was only capable of VaguenessIsComing messages. Her actions only pushed her friends into fighting a brutal war.]]

%% This page has been alphabetized. Please add new examples in the correct order.

** Moira Queen is the indirect cause for the events of Season Three. During the events of Season Two, prior to her death, she informed the League of Assassins of Malcolm Merlyn's survival. The League, specifically Ra's al Ghul himself, were ''not'' happy with Malcolm after the Undertaking, and marked him down for death. Malcolm became so desperate to get off the League's hit list that he went as far as to brainwash Thea, ''his own daughter'', into killing Sara Lance, and taping it to blackmail Oliver into accepting the blame for Sara's death and issuing a challenge to Ra's al Ghul -- by killing Ra's, Oliver would be able to get everyone, even Malcolm and Thea, out of the red.
* ''Series/BandOfBrothers'' has Dick Winters and Moose Heyliger deciding to take a stroll one evening just to check on the men's morale. A sentry mistakes them for the enemy and [[UnfriendlyFire shoots Moose]]. This results in him being pulled off the line and the incompetent Lt Dike is put in charge of Easy Company - just in time for the horror of Bastogne and the Battle of the Bulge, during which many men lost their lives. The sentry in question was quickly transferred to another regiment for his own safety.

** [[Recap/DoctorWhoS30E1PartnersInCrime "Partners in Crime"]] has a minor example — Donna unwittingly causes Stacey Campbell's death by fiddling with the Adipose Industries necklace she stole. This causes an Adipose to be created from Stacey's fat cells out of schedule, which she witnesses, leading the company's head, Miss Foster, to convert the rest of her into Adipose in order to hide what the company is doing.

** Subverted with Harrison Wells in Season One. Initially, it's played off as though the particle accelerator explosion in the pilot was a complete accident (which would be this trope). However, eventually, after the revelation that he is in fact secretly [[spoiler:Eobard Thawne aka Reverse Flash]], we end up learning that he intentionally created the explosion in order to give Barry Allen his speed and create Flash's famous Rogues Gallery in order to eventually have Barry go back in time so he could return to his time period.
** Played straight in season six with Nash Wells. He becomes so desperate to get revenge on the Monitor that he ignores how convenient all of the events that lead him to Earth-1 are, and ultimately [[spoiler:releases the Anti-Monitor from his prison and unleash an antimatter wave on TheMultiverse, thus causing ''Series/CrisisOnInfiniteEarths2019''.]]

*** His decision to support the Lannister regime in Season 2, just to prevent Stannis and Melisandre from taking over, leads the corrupt Lannister regime to assert its dominance, as a result of which Westeros becomes a chaotic despotic regime ruled by Cersei Lannister who plunders, robs, and murders her supports creating a regime where the likes of Euron Greyjoy and the corrupt Iron Bank are in charge. Likewise, by hampering Stannis' campaign, he damaged the only candidate of Westeros who could have peacefully resolved the War of the 5 Kings and rallied Westeros for defense in the Long Night, since Stannis' attempt to aid the Night's Watch and rescue the North from the Boltons collapsed because of a lack of support, and Jon Snow is meaningfully hampered in trying to pick up where Stannis left. Much of this could have been avoided had it not been for Varys.

** Baelfire is one of the main causes of the plot in the show. His father Rumpelstiltskin became the Dark One to protect him from becoming a child soldier. [[spoiler:His disappearance into another world]] is what caused Rumpelstiltskin to search for a land without magic - and so create a curse dooming the entire populations of multiple worlds to years of misery. All of Rumple's deals and schemes, including turning Regina Mils into a "monster," was part of his plan to [[spoiler:find Baelfire.]]

** Mr. Gold's [[KickTheSonOfABitch pursuit for revenge at the end of season 3]] winds up severing the ties with that arc's BigBad and her AmplifierArtifact. This results in the magic triggering her [[spoiler:TimeTravel spell which got Emma and Hook trapped in the past where they, [[NiceJobBreakingItHero along with several other things]], end up bringing with them a golden urn that spills over, leading to the release of Elsa and the first half of Season 4's plot]].
** The season 4 crossover arc with ''WesternAnimation/Frozen2013'' is another case, according to the episode "The Snow Queen". Basically, the Duke of Weselton tried to seduce his betrothed Helga's sister Ingrid. This caused Helga to be killed by Ingrid, which causes Ingrid's other sister Gerda to develop a fear of her family's magic, which led to her and her husband seeking to find a way to treat Elsa's magic, and caused the events of the movie to happen and the events of the ''Frozen/OUAT'' crossover to happen.

* Halfway through season 3 of ''Series/PersonOfInterest'', Simmons kills [[spoiler:Carter]] in revenge for the fall of HR. This causes Reese to go into a TenMinuteRetirement, requiring Fusco to track him down and drag him back to New York. This leaves Team Machine critically understaffed during their next case, while allows Decima to get a hold of the source code of the Samaritan AI, which would become the BigBad of the next two seasons. That's right: a revenge murder by a DirtyCop at the wrong moment nearly caused the entire world to be taken over by an evil supercomputer.

* Valerie in the ''Series/SabrinaTheTeenageWitch'' episode "Sabrina and the Beanstalk". She decides to phone Sabrina to ask about shampoo, which makes Sabrina forget she was supposed to pick up spell ingredients from the Other Realm. When she gets off the phone, the store is closed, so Sabrina substitutes the ingredients for magical jumping beans. When they don't work, she throws them out and a beanstalk grows in the backyard. What's more is that Harvey eats one and gets sent to the top of the beanstalk - where he bumps into a WickedWitch (apparently '''the''' [[UrExample Wicked Witch]]) who likes to eat mortals.

* Narrowly {{averted}} by Princess Mithian on ''Series/{{Merlin|2008}}'', who, in a bid to impress KingArthur, shoots a young deer in the forest. Unbeknownst to her, the deer is actually [[BalefulPolymorph Guinevere under an enchantment]]. Only Merlin realizes what she's done and returns to the forest at night to hunt for Gwen and heal her from her injury.

** Played straight in season six with Nash Wells. He becomes so desperate to get revenge on the Monitor that he ignores how convenient all of the events that lead him to Earth One are, and ultimately [[spoiler:release the AntiMonitor from his prison and unleash an antimatter wave on the multiverse, thus causing ''Series/CrisisOnInfiniteEarths2019.]]

** Yeong-shin thought that he was just feeding a bunch of starving people when he [ImAHumanitarian put Dan-i's body into the stewpot]]. Suddenly, what was a very limited and isolated condition becomes dozens of highly-infectious zombies.

* In ''Series/TheAndromedaStrain'', the satellite containing the eponymous [[ThePlague plague]] crashes near two teenagers who decide to pick up the satellite and bring it back to town where it is opened by the clueless and curious townsfolk, which unleashes the plague and decimates the town. Had the military actually gotten to the satellite first, they planned to open in a much more secure location, averting the crisis.

** Julia is pretending to be her dead twin sister Sara half to hide from the PoliceState, half because her brother-in-law Hugo needs Sara to be alive to keep a job. The police eventually takes her in for interrogation as Sara, and Hugo insists on going with her. This happens while Hugo and Julia's employer Luis is visiting Julia's mother. With Hugo away, Luis is driven home by Hugo's brother Álex. By that point, Álex has met a few members of LaResistance, including a RichKidSocialActivist who lives in the same area of town as Luis. Of course, Álex being Luis' driver instead of Hugo results in him finding out who the resistance member is in real life.
** [[spoiler:Julia's legally dead boyfriend Carlos breaking into the room used by Hugo's daughter to drop off an item he want Julia to find]] results in Hugo getting worried enough about his daughter's safety to bring her to work with him. One of Hugo's employers spent time using his daughter as experimental subject, and the girl being in their house allows for the experiments to continues without Hugo being the wiser.
** An acquiantance of Hugo's and Julia's employer dying via an implied assassination results in the employer's orphaned nephew being underfoot.