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[[quoteright:279:[[VideoGame/SuperMarioBros3 http://static.tvtropes.org/pmwiki/pub/images/didnt-think-this-through_crop_smb_5505.jpg]]]]
[[caption-width-right:279:Somehow, I don't think you thought your cunning plan all the way through.]]

->'''Mr. Krabs:''' Plankton! You knew I would never distrust a dollar!\\
'''Plankton:''' That's right, Krabs! Now hand over the Krabby Patty secret formula!\\
''[Beat]''\\
'''Mr. Krabs:''' Or what?\\
'''Plankton:''' I don't know. I never thought I'd get this far.\\
'''Mr. Krabs:''' Well then, allow me to suggest your next move.\\
''[Mr. Krabs flushes Plankton down the toilet]''
-->-- ''WesternAnimation/SpongebobSquarepants''

A situational trope. One character will develop a plan designed to solve a certain problem they're encountering. However, due to their failure to plan ahead, there is a massive gaping flaw in their plan that they, and also perhaps the audience, missed. As a result, they are now in a situation where, rather than winning, they are stuck with either a stalemate or an outright loss. As indicated by the page quote, this may occur because the character never thought that their plan would actually progress as far as it did in the first place.

A more comedic, simple version of DidntSeeThatComing. See also AndThenWhat, when the flaw is not knowing what to do if the plan succeeds. If the person pointing this out is sufficiently annoyed, this can lead to WhatWereYouThinking. May also lead to a ThisIsGonnaSuck for the schemer when he realizes how screwed he really is. Compare MissingStepsPlan.

----
!!Examples!!

[[foldercontrol]]

[[folder: Anime and Manga]]
* Vegeta during the Saiyan battle in ''Anime/DragonBallZ'' after Gohan turned into a Oozaru. Escaping being crushed multiple times, he did seem proud of himself for a moment after cutting off the boy's tail, thus shrinking him to normal size. Given that, while Vegeta has taken a considerable beating fighting the various heroes, Gohan was the last one strong enough to present any kind of threat to him, it seems that [[TheBadGuyWins he's won]]. [[OhCrap Then comes the brief realization]] that Gohan is still semi-gigantic, not maintaining his place in the air and now falling towards him while semi-gigantic. All of this happens in about a second, leaving Vegeta no time to dodge. Not long after a crushed Vegeta is sitting in a crater, struggling to crawl to his ship.
** it's a running theme in this series that various character usually don't think their actions through, and end up suffering for it.
* Almost happens in ''Manga/MahouSenseiNegima''. The cast are discussing ways to retrieve Asuna and the Great Grandmaster Key from the Big Bads, and get the idea to use Natsumi's artifact (which makes the enemy completely unable to sense your presence) to get close for an ambush. Unfortunately [[spoiler: The AntiMagic field coming from Asuna would make that plan useless.]] They almost go with the plan until Ako realizes the flaw. Cue Yue coming up with a workable solution, and a CrowningMomentOfAwesome for everyone involved.
* ''Manga/OnePiece'' has the "Fake Straw Hat Pirates" based in Sabaody Archipelago after the time-skip. Since Monkey D. Luffy has attained even more infamy than ever before due to his part in the War at the Summit, one guy going by the name "Three Tongued" Demalo Black got the ''[[SarcasmMode bright]]'' idea of posing as him and setting up a crew to pose as the Straw Hat Pirates, usually getting his way by relying on Luffy's fame to threaten people and recruit fearsome pirates into his crew. Unfortunately, around the time they were recruiting, the ''real'' Straw Hats came back, and it got steadily worse when they try to recruit a pair of AxCrazy pirate captains who intend to kill the Straw Hats for more fame, and then Marines show up with [[MechaMooks Pacifistas]], with a Marine Captain personally knocking out Demalo Black with his axe [[TooDumbToLive for trying to talk smack to him while pretending to be Luffy]]. Because he forgot when you're one of the most infamous pirates on the planet, ''lots of actual strong people want to kill you.''
** During the Paramount War, the heroes expend an extraordinary amount of effort to get Luffy to [[spoiler: Ace's execution platform.]] Only after he gets there does he, and everyone else, remember that [[BigBad Sengoku]] is standing ''right next'' to their goal.
* At points in both the first and second seasons of ''Anime/StrikeWitches'', Minna pulls a gun on Mio in order to try to stop her from getting herself killed in battle. Mio is quite aware of the flaw in this bluff, and it doesn't work either time.
* [[spoiler:Harumi Kiyama]] in ''Manga/ACertainScientificRailgun'' plays this both ways. On the one hand, she's the only villain who realizes the damage her plot is causing, and actually creates a way to reverse the effects harmlessly once she's finished. On the other hand, she failed to account for what would happen if people randomly fall into a coma--such as if they're driving a car.
* In ''Anime/GirlsUndPanzer'', the Oarai student council revives its Tankery program in order to compete in a national tournament [[spoiler:which is a lie to cover up the fact that the school will be shut down, but they have made a deal to prevent that if they win]]. Unfortunately, the student council overestimated how many tanks they had left over, [[spoiler:i.e., the ones they weren't able to sell]], assuming that the school would have many in reserve from its past participation in tankery. StudentCouncilPresident Anzu admits that her assumptions were faulty, [[spoiler:but she couldn't think of any other way to keep the school open, and at least wanted them to have hope.]]

[[/folder]]

[[folder: Comic Books]]
* In the climax of ''Northwest Passage'', Montclave reveals critical information to Simon in the hopes of permanently turning him against his father, Charles Lord. [[spoiler: The information is that Simon's parentage is a LukeIMightBeYourFather situation, since Montglave raped Simon's mother at the time of conception. Unsurprisingly, Simon takes a rather dim view of this knowledge and promptly blows Montglave's brains out.]]
* ''Franchise/{{Batman}}'' villain Warren "Great White Shark" White successfully plead insanity to escape embezzlement charges. He was [[ComicBook/ArkhamAsylumLivingHell sent to Arkham]] and wound up at the mercy of Gotham's worst psychopaths. Oops.
* Doctor Octopus's plan in the ''ComicBook/SpiderMan'' storyline ''ComicBook/{{Ends of the Earth}}''. With the evil doc dying, Doc Ock plans to [[spoiler: flash-fry the Earth, leaving approximately .08 percent of humanity to live on and remember him as the greatest monster that ever lived]]. However, Spidey points out a glaring flaw in this plan: [[spoiler: they'll live. Brain dead, their brains flashfried, too.]] Doc Ock [[VillainousBreakdown flips]].
* In one issue of the ''WesternAnimation/BatmanTheBraveAndTheBold'' comic, {{Nightwing}} leads the {{Robin}}s from other points in time (Jason Todd, Tim Drake, Stephanie Brown, Damian Wayne and [[TheDarkKnightReturns Carrie Kelly]]) to one of Ra's al Ghul's bases in order to use a Lazarus Pit to save Batman's life. When they encounter the League of Assassins, Damian leaps out, demanding that they stand down as is his birthright as an al Ghul. The assassins look at each other, then charge at the Robins. Damian then remembers that he's not born yet.
* In an episode of ''Bruchbach Serenade'', Rick has just finished his summer job at city hall. In order to maximize his earnings, he had made the mayor give a speech that made fun of the audience and incorporated Nazi phrases, so he could sell the audience rotten tomatoes. Now the people in charge refuse to give Rick a certificate for the job.
* ''ComicBook/SonicTheHedgehog'': Dr. Eggman realizes that [[ComicBook/SonicTheHedgehogMegaManWorldsCollide trying to stop Super Sonic's]] ResetButton attempt was "a bit hasty" on his part. [[spoiler:When he finds a gigantic purple crack on Mobius' surface, he's quick to upgrade it.]]
* In ''ComicBook/{{Runaways}}'', during their first battle against Excelsior, Chase Stein decides to create a distraction by attacking with the Leapfrog's lasers... which quickly drains the Leapfrog's batteries, forcing the Runaways to flee with their highly distinctive vehicle fully exposed (because without battery power, they can't activate the vehicle's stealth mode) making it easy for Excelsior to track them down.
* During the Civil War arc, Jennifer Walters was outed as She-Hulk (again) by a New Warriors hate site. On the way into her office through an angry mob to help some former New Warriors keep their identities hidden from the public, one of the mob recognized her, grabbing her by the arm and ripping her shirt, proudly exclaiming "I've got She-Hulk!" Jen shifted and hoisted the guy up by his lapels.
--> '''She-Hulk:''' Alright, you've got She-Hulk! Now what?!
--> '''Angry Citizen:''' I. . . uh. . . guess I didn't think this through. . .
[[/folder]]

[[folder: FanWorks]]
* ''Fanfic/AllYouNeedIsLove'': L's plan to expose Light as Kira hinges on [[spoiler: [[ThanatosGambit Light trying to kill him]]]] but Light doesn't need to [[spoiler: kill L]]. All he has to do is [[spoiler: kill [[TheCaretaker Watari]]]] and [[FlawExploitation L's system collapses.]]
* ''FanFic/VoldemortGoesBackToSchool'': [[VillainousBreakdown in a state of panic,]] Voldemort creates massive wards on an abandoned classroom door that only Dumbledore or Grindelwald could hope to break in the hopes of avoiding further interactions with Harry and Draco. He realizes the gaping flaw in his plan when he begins to worry that [=McGonagall=] might get around his wards if she were to transfigure the door into something else and as it is Harry circumvents the door and all of his carefully laid warding altogether by dropping in through the window on his broomstick. And because he's so heavily warded the door he's essentially locked himself in.
** Later [[KingIncognito Voldemort (in his schoolboy disguise)]] [[WhatAnIdiot antagonized Snape, the only person who can supply him with the potions he needs, and hopes to just control him with blackmail and didn't think to obliviate him afterwards.]]
* One of the antagonists of ''FanFic/TheNuptialverse'' story ''Families'' is an ImmortalitySeeker who riled up a huge anti-Princess group and took Twilight Sparkle and Rainbow Dash, among others, hostage in order to force Princess Celestia to divulge the secret of her and Luna's immortality. Celestia's response is to laugh in his face and point out all the holes in his plans, such as having no way to avoid royal retribution after everything was done, almost certainly not having {{Power Limiter}}s strong enough to hold Twilight, and (accurately) stating Rainbow is useless as a hostage because she would never want Celestia to risk all of Equestria for her sake alone.
* ''FanFic/{{First Try Series}}'' has Sasuke realizes this during his confrontation with Itachi during the Search for Tsunade arc. Namely Sasuke notes that Itachi used to be in ANBU before becoming a criminal on the run and he's been a Genin for little over six months. Right before he gets [[MindRape hit with a Tsukuyomi]] he says the trope name verbatim.
* Neji in ''[[https://www.fanfiction.net/s/5537220/12/The-Darkest-Light The Darkest Light]]'' realizes this after he tries to have Hinata "manhandled" by hiring Naruto/Naruichi to give her a massage. Not only does Naruichi have an acceptable explanation for [[NotWhatItLooksLike what Hiashi walks in on]], he also has the receipt saying he was hired by Neji.
* In Fanfic/OfWhiteTreesAndBlueRoses, Rhaegar's abduction of Lyanna blew up spectacularly. Also, the Knight of the Laughing Tree participating in the Tourney of Harrenhal.
* ''[[https://www.fanfiction.net/s/7774132/3/Oops Oops]]'' has this happen for [[Literature/HarryPotter Harry's]] (accidentally made) [[SoulJar horcrux]]. It gets Harry to brew and drink a luck potion of the "May you live in interesting times" variety by making him think it was a good luck potion. After Harry calls the horcrux out on not only how messed up his luck usually is but that he's already in Britain during World War II, the horcrux admits that it didn't think things through but in its defense, Harry rarely does either and it is a portion of Harry's soul.
[[/folder]]

[[folder: Films - Animated]]
* ''TheIronGiant'': Mansley, single-mindedly obsessed with destroying the Giant, personally orders the ''Nautilus'' to launch a nuke at the Giant after the military realizes that they were tricked, failing to realize at that moment that the missile was locked on to the Giant's current location; as the Giant is standing right in the middle of Rockwell at that very moment, the nuke will take out the entire town, including Mansley himself, when it hits. Fortunately, the Giant intercepts the nuke itself and saves the town.
* In ''Disney/{{Aladdin}}'', [[EvilChancellor Jafar]] is defeated when Aladdin tricks him into wishing to become an all-powerful genie. Jafar either forgot or was not aware that genies in this setting are bound to a magic lamp and obliged to grant wishes ''by nature''.
--> '''Genie:''' It's all part and parcel of the whole Genie gig. [[LargeHam PHENOMENAL COSMIC POWER!]] ... Itty-bitty living space.
** Actually, it's even worse. Right when he makes the wish, Jafar angrily addresses Genie as "slave" -- which is what he becomes in turn.
* Gil's plan to escape to the sea in ''WesternAnimation/FindingNemo'' which succeeds past the audience's expectations only to run into a snag at the end.
* A StrangeMindsThinkAlike style gag in ''MeetTheRobinsons'' often said to Bowler Hat Guy. When a CEO, a frog and a Tyrannosaurus Rex think your evil plans need work, you aren't doing that well.
-->"It's just, I have this big head, and little arms. I'm just not sure how well this plan was thought through!"
* The last line on ''WesternAnimation/CloudyWithAChanceOfMeatballs'', spoken by [[spoiler: the Mayor, who is adrift at sea after eating the food boat he was escaping in.]]
* ''WesternAnimation/RecessSchoolsOut'': Why did Prickly call the villain insane? Maybe because [[spoiler: creating another ice age to end summer vacation forever would bring forth TheEndOfTheWorldAsWeKnowIt]]?
* ''WesternAnimation/KungFuPanda2'': Po's plan to rescue the Furious Five where he admits he hadn't thought what he would do when he got close enough to do that. Mainly due to the fact he didn't expect to make it this far.
* ''SinbadLegendOfTheSevenSeas'': After braving many dangers, Sinbad and Marina finally make it to [[EldritchLocation Tartarus]] and come face to face with [[PhysicalGod Eris, the goddess of discord]]. The faces they make ''really'' show that they didn't have any plan whatsoever past that point.
[[/folder]]

[[folder: Films - Live-Action]]
* In ''Film/MontyPythonAndTheHolyGrail'', when King Arthur's knights attempt to copy the Trojan Horse ploy with a giant wooden rabbit, none of them remember that they're supposed to get inside the rabbit until after it's been taken into the castle.
** Of course, given the French knights' predilection for catapulting just about everything they can find, actually getting into the rabbit would have been even worse.
** [[ExplainExplainOhCrap Look, if they had just built a giant wooden badger]].....
* {{Lampshaded}} in ''Film/ThreeAmigos''. Dusty Bottoms has found Carmen in her place of imprisonment.
-->'''Dusty:''' We have a plan.
-->'''Carmen:''' What is it?
-->'''Dusty:''' First, we break into El Guapo's fortress.
-->'''Carmen:''' And that you've done. Now what?
-->'''Dusty:''' Well, we really didn't expect the first part of the plan to work, [[IndyPloy so we have no further plan]]. Sometimes you can overplan these things.
* Hermione says this very thing to Harry in the ''Literature/HarryPotterAndThePrisonerOfAzkaban'' movie, when she saves their past selves from the werewolf... by luring it over to their current selves.
* ''Film/TheDarkKnight''
-->'''Fox:''' {{Let me get this straight}}. You think that your client, one of the wealthiest, most influential men on the planet, is secretly [[Franchise/{{Batman}} a vigilante who spends his nights beating criminals to a pulp with his bare hands]]. And your plan is to blackmail this person? ... [[WhatAnIdiot Good luck]].
-->'''Reese:''' *{{beat}}* ... [[ScrewThisImOuttaHere Keep that]]...
* In ''ItsABoyGirlThing'' Woody ([[FreakyFridayFlip in Nell's body]]) decides to get her a reputation for being easy. So he decides to have her sleep with this really sleazy guy. The DidntThinkThisThrough example occurs just before the deed is to be done when Woody realizes that ''[[GenderBender he]]'' is actually going to be the one to experience the drunken sex with a guy. Also counts as an OhCrap moment.
* Done ''hilariously'' in ''Series/MysteryScienceTheater3000 TheMovie'' with Crow's plan to ''tunnel out of the Satellite while it's in orbit''.
-->'''Crow:''' Oh, wow, this ''is'' confusing! Hey, Mike! Can you hand me my calculations? ''[paper flies into his mouth]'' Thank you! Oh, well, look at that: "Breach hull, all die!" Even had it underlined!
** Then lampshaded with his explanation:
-->'''Crow:''' Well, believe me, Mike, I calculated the odds of this succeeding against the odds I was doing something incredibly stupid and... I went ahead anyway.
* In ''Film/TheRundown'', the sidekick's "Thunder and Lightning" attack never works. He becomes dumfounded when it does work and needs a moment to think up the next stage of the attack.
* In ''Film/TheAvengers'': "Okay, we've got its attention. What the hell was step two?"
* In ''Franchise/PiratesOfTheCaribbean'' Elizabeth stabs her host/captor captain Barbossa with a knife. It somehow slipped her mind, that even if she'd succeded, she would still be on a ship full of vicious pirates, whose captain she just killed, in the middle of the raging sea.
* ''Series/{{Rome}}''. Brutus and his fellow conspirators kill Caesar, justifying it by declaring him a tyrant. However Marc Antony points out that if Caesar is a tyrant, by Roman law all his previous acts are void, including the appointment of the conspirators to their positions of power. Rather than risk an election (given that Caesar was well thought of by the common people) they're forced to make a truce with Antony (giving him time to rally the mob against the conspirators with his RousingSpeech at Caesar's funeral).
* At the climax of ''Film/GhostRider'', Blackheart absorbs the souls of the damned of San Venganza, which makes him ''incredibly'' powerful and ''incredibly'' [[AssimilationBackfire susceptible to the Ghost Rider's Penance Stare]] (which he had [[NoSell shrugged off]] in their previous encounter).
[[/folder]]

[[folder: Literature]]
* ''Literature/TheHobbit'': To enable the dwarves to escape from the Wood Elves, Bilbo secures them inside barrels so they can float away downriver. Unfortunately:
-->It was just at this moment that Bilbo suddenly discovered the weak point in his plan... Of course he was not in a barrel himself, nor was there anyone to pack him in, even if there had been a chance!
** Not that being packed into a barrel himself would have been an improvement. Getting out again wouldn't have been easy.
** Not to mention ''the entire journey itself.'' The one weak spot in the dwarves' scheme to get their gold is that Smaug is still sitting on it, and a baker's dozen of dwarves are no match for the dragon, which is why Gandalf insisted that they rely on burglary. However, Bilbo, seeing the size of the hoard he's supposed to steal, states that they should have brought an army of burglars, as there's only so much he can steal at once. Then Smaug smugly asks Bilbo how he's supposed to get his share back home. Only a series of lucky breaks (for a given definition of [[BittersweetEnding luck]]) keeps the adventure from going to waste.
** [[Film/TheHobbit The movie]] works around this by planning to have Bilbo fetch the Arkenstone, which can be used to convince all the armies of the six other dwarven settlements to come to Thorin's aid.
* Twice in ''[[KittyNorville Kitty Goes to Washington]]''. Kitty had good reason to [[spoiler: banish Elijah Smith back where he came from]], but she didn't consider that this would mean [[spoiler: the collection of vampires and lycanthropes under his control would then be ''out'' of control. Cue chase scene, followed by calling in backup to deal with the fallout.]] Later, Kitty tries to distract the guards on the first floor of a building by throwing rocks at the upstairs windows, hoping they'll investigate the crash. She realizes belatedly that if they instead put two and two together and look out on the street, she'll get caught red-handed. (Luckily, they're [[TheGuardsMustBeCrazy typical guards]].)
* In the ''KnightAndRogueSeries'', when told he must, in order to regain his legal rights, capture a murder suspect he released from jail and become his brother's steward, Michael sets out to bring the criminal to justice. Upon learning [[spoiler: she's innocent]] he decides to not even bother with bringing her to trial, opting to be tattooed as a horrible criminal instead. It's not until afterward that he realizes this will make people hate him by default and take advantage of him due to his being unable to go to the law for help. Bonus points for his father forcing the situation on him in the hopes that only his oldest son will hire Michael for a stable job if he's marked, as he apparently didn't notice that Michael spent the whole past year funding his adventures by stopping for the day in random towns and doing odd jobs for people who don't need to see the area on his arm where he gets marked.
* ''Literature/HarryPotterAndTheChamberOfSecrets'': The Trio devises a plan to impersonate students from House Slytherin, so that they could sneak into the Slytherin's dorm and hopefully uncover some information about the titular Chamber. They spend a month concocting an extermely advanced shapeshifting potion, and make some thoughtful arrangements, like stealing appropriate robes and preparing drugged cupcakes to put said students out of conditions for the duration of their foray. Finally, everything is ready, and they perform the transformation... whereupon they realise that they have no idea where the Slytherin dormitory is.
** In the same book, Harry and Ron miss the train to go to Hogwarts, and in order to get there they steal Mr. Weasley's flying car. They promptly get seen by about seven Muggles across England. As [=McGonagall=] points out to them, they had an owl and perfectly legitimate reasons to be late, so they could have just sent a message to be picked up.
** There's also Viktor Krum's ill-fated transfiguration during the second task of the Triwizard Tournament in ''Literature/HarryPotterAndTheGobletOfFire.''
* ''[[Literature/TheStainlessSteelRat A Stainless Steel Rat Is Born]]'': Young Jim diGriz gets himself imprisoned so he can [[HadToComeToPrisonToBeACrook meet other criminals and learn from them]]. The problem is that the criminals he finds in prison are the ones who were ''dumb enough to get caught''.
[[/folder]]

[[folder: Live Action TV]]
* In ''TheWire'', Detective [=McNulty=]'s cunning plan to fake a serial killer in order to get money for an investigation into a murderous drug crew becomes a textbook example of this. Although command showers him with resources, people gradually get wind that he's giving overtime out to people for different cases, so he ends up getting blackmailed into giving people overtime to go and play golf in Florida. Because the eventual bill runs into the millions, [=McNulty=] makes himself liable for not only firing, but serious jail time. Because the case becomes a political football, he ends up having to bullshit the entire police command staff and all of city hall. And because [=McNulty=] hadn't thought what he'd do when the drug crew were busted, leaving him with a non-existent "serial killer" to catch, he ends up having to find a way to de-escalate the thing rapidly. For a while, you think he'll manage to stay on top of things. [[spoiler: He doesn't. The wheels come off. Spectacularly.]]
* An episode of ''Series/BlakesSeven'' [[PlayedForLaughs plays this for laughs]] with its [[JustifiedTrope justification]]: when Vila asks Tarrant if he can actually dock their tiny ship into the [[CoolShip Liberator]] that they have just reclaimed from [[BigBad Servalan]], the following exchange occurs. (Incidentally, it's just a throwaway gag, since the very next scene has them already back on the Liberator safely.)
-->'''Tarrant:''' I hadn't really considered it.
-->'''Vila:''' What?
-->'''Tarrant:''' I thought we'd be dead by now.
* ''Series/BuffyTheVampireSlayer'':
** Spike schemes to both break up the Scooby Gang and plant evidence to lead Buffy into a trap. It takes the BigBad he's working for to point out that he's given Willow the evidence, and Willow won't be speaking to Buffy now.
** Apparently, when she had Willow activate all Slayers worldwide, it never occurred to Buffy at that moment that not all of the newly empowered Slayers would be willing to use their powers for good, with one Slayer in particular, Simone Doffler, becoming a terrorist and obsessed with killing her.
* In the ''Series/DoctorWho'' episode "World War Three", the Slitheen get into 10 Downing Street, and chase the Ninth Doctor, Rose and Harriet Jones. The Doctor activates a defence mechanism that means there is 3 inches of thick metal between them and the Slitheen - or any way of escape.
--> '''The Doctor:''' They'll never get in.
--> '''Rose:''' But how do we get out?
--> '''The Doctor:''' ... Ah.
* In a ''Series/SavedByTheBell'' episode, Zack has detention on the day of a trivia contest for a trip to Hawaii. He sends Screech in his place, who comes back to ask him a question. Mr. Belding explains only those in detention can talk to others there, so Screech purposely gets in trouble. When he sits down, Zack tells him the obvious problem with that plan.
* On an episode of ''Series/{{Seinfeld}}'' Kramer is at a department store when he decides to sell the clothes he's wearing to another customer. When he's left naked in the store's changing room with nothing to put on, he whimpers, "I didn't think it through!"
** Kramer does this kind of stuff a LOT. Like betting that he would turn his apartment into a triple tiered deck.
** Topped when he tells Elaine a story about how he was going to return a pair of pants he had borrowed to a friend. On the way, he slipped and fell in mud, ruining the pants he had intended to return. When Elaine confirms that he was wearing the pants he planned to return, [[FridgeLogic she asks the obvious question of what he would have done had he successfully returned the pants and been left without anything to wear.]] His response? [[InsaneTrollLogic He never got that far, so it doesn't matter.]]
* In an episode of ''Series/TopGear'', there was an amphibious car challenge, Hammond's car looked like a boat (with the steering wheel near the back) with an upper portion for the "girls in bikini to go," which he then noticed was so high up he couldn't see over while driving.
** Then came Jeremy Clarkson's mobility scooter in Season 18, which was arranged so that the drive wheels had nothing actually pressing them against the ground.
** The motorhome challenge: Clarkson designed a three story home on top of his car. It was barely able to clear overhead passes, and proved to be top-heavy, nearly tipping over several times on the road, and finally did during a very windy night.
** None of their cop car vehicle-stopping devices proved well planned. Richard neglected to consider that cars can turn; James neglected to consider that cars have windscreen wipers; and Jeremy neglected to consider that a car's axle can handle only so much stress. The net result was that none of them managed to stop the Stig and as an additional bonus one of Jeremy's wheels [[FreeWheel ended up a substantial distance from his car.]]
* ''Series/TheBigBangTheory'' shows [[OnlySaneMan Leonard]] trying to slip out to meet his then-girlfriend and getting [[CannotTellALie Sheldon]] to cover for him. Given that Sheldon cannot do this convincingly, Leonard almost immediately wonders why he didn't think this through.
* (Also counts as a Real Life example) ''TheTonightShow'' - Johnny Carson would often have non-celebrity regular folks as guests (often the most interesting and entertaining part of the show) - one was a self-styled "idea man" who came up with get-rich schemes, none of which really panned out. He had high hopes for his latest - shaving his head and painting advertising on it (this was way, way before shaved heads were commonplace). Johnny commented that, coming on this show, he must have been able to charge some pretty high rates - and the guy froze...''he never thought of that.'' Johnny tried to keep the tone light, but the guy spent the rest of his time there looking like he'd swallowed a foul-tasting bug.
* In one episode of ''Series/ThirtyRock'', Kenneth pitches an idea for a game show he had to Jack: a show like ''Series/DealOrNoDeal'' where the contestants must find out which briefcase has a million dollars of gold inside. While filming it, the contestants only need to look for which model is having difficulty holding her briefcase. The show is then quickly canned. Kenneth even lampshades it:
-->"Ooooh, gold's real heavy, innit?"
[[/folder]]

[[folder: Music]]
* [[http://www.youtube.com/watch?v=3FAFbvZYyvE Have you heard the story of Bottleneck Bob?]] He tried to rob the train with cattle, but evidently forgot they needed to be corralled somehow: "The cattle ran all over the place / And there was Bob with the longest face"
[[/folder]]

[[folder: Newspaper Comics]]
* [[http://www.dilbert.com/2011-10-22/ This]] ''{{ComicStrip/Dilbert}}'' strip.
* In one ''ComicStrip/CalvinAndHobbes'' comic, Calvin creates the world's biggest snowball, and comments how he can't wait to throw it at somebody... that is until Hobbes asks him how he was going to pick it up.
[[/folder]]

[[folder: Video Games]]
* In ''VideoGame/BioShockInfinite'', Booker and Elizabeth risk life and limb to get to Chen Lin's impounded tools, only to realize when they get there that the "tools" are more like ''machines'' — way too big (and numerous) to be transported ''anywhere'', let alone all the way back the way they came from the shop. Booker even lampshades it:
-->'''Booker:''' Well we sure as hell aren't gonna be able to ''carry'' all this back to the shop. ''God'' we didn't think this all the way through...
* A frequent experience in ''VideoGame/{{Bomberman}}'': Place bomb, walk into alley, [[ExplosiveStupidity realize alley is a dead end because of said bomb...]]
* VideoGame/WorldOfWarcraft:
--> '''Draenei Male:''' Step one, we land the Exodar. [[MissingStepsPlan Step three, we defeat Legion and go home.]] There is only one detail missing...
* In ''VideoGame/KingdomHeartsChainOfMemories'', Larxene is trying to cheer Namine up about the plan. Namine replies that they want part of Kairi to replace Kairi in Sora's memories so that he'll forget Kairi. Spot the flaw in this plan.
* Something you can do in Smackdown vs Raw 2011 ladder matches. Have you and your partner both climb up a ladder. The opponents get up and realize they could just tip the ladder over. Cue doing just that.
* Much of the "[[BlackComedy fun]]" in ''VideoGame/DwarfFortress'' comes from the player neglecting to think things through, such as forgetting to make a proper drainage system for your water (or magma!) devices, cooking all the fort's seeds so they have nothing to plant for crops, building a prosperous fort without regard for thieves, [[GravityIsAHarshMistress knocking the last support out from under your megaproject]]...
* Name a [[Franchise/MetalGear Stealth]] [[{{Manhunt}} Game]], any [[SplinterCell Stealth]] [[Franchise/AssassinsCreed Game]], where a player gets impatient and decides to do something such as enter an unknown area without scouting ahead, shoot/stab someone in plain view, or run past a guy thinking "he won't see me if I'm fast about it." [[SaveScumming Load previous save and hopefully learn from your mistake]].
* ''VideoGame/PokemonBlack2AndWhite2'' has a fabulous example from [[spoiler: Ghetsis, surprisingly. He orders Kyurem to attack the player character directly, [[BatmanGambit rightly expecting this to force N into action to stop the attack]], so he can steal N's legendary dragon and fuse it with Kyurem, which he controls. The thing he didn't take into account? N's actions ''did'' save the player character...]]
* In the ''VideoGame/MassEffect3 Citadel DLC'' Shepard is targeted by someone who wants to be Shepard. [[ButtMonkey No, not Conrad,]] it turns out a plan to kill and replace Shepard [[spoiler: by a Shepard clone.]] Turns out they're a BadBoss, worse than pure renegade Shepard and a xenophobe. If the idea is to become the legend then they'd need to gain crew loyalty for the suicide mission, follow the paragon path Shepard had only to find out they're hosed upon learning Shepard's love interest is an alien.
* In the ''VideoGame/{{Borderlands 2}}'' expansion ''Mr. Torgue's Campaign of Carnage!'', one side mission you get from Mr. Torgue involves a contaminated batch of beer being served at the tournament (a diseased midget fell in the vat). [[InsaneTrollLogic Mr. Torgue hires you to do a "product recall", and by "product recall" we mean "storm the bar the beer went to, kill everyone inside, and get the beer back so nobody gets hurt by the contaminated beer."]] Only when you've completed the mission does Mr. Torgue realize that what he just asked you to do "MADE NO SENSE G*D DAMNIT!"
** He later hires you to go kill people with Torgue guns so he can use footage of it in an advert for Torgue guns. A ''radio'' advert. This time he doesn't realize it.
* In ''VideoGame/StarWarsTheOldRepublic'', the Republic has a top-secret prison on the planet Belsavis, where they send people who will never be allowed back into the galaxy again. Unfortunately, they never thought about what would happen when a closed population inevitably started having children, none of whom had ever been convicted of a crime, yet were still considered prisoners. Eventually, these descendants started a movement to gain their freedom, which left them open to the Empire's offers...
[[/folder]]

[[folder:Web Animation]]
* In episode 8 of ''WebAnimation/{{RWBY}}'', Weiss falls out of the sky. [[ButtMonkey Jaune]] leaps up and catches her in his arms. He manages to look badass for a moment, then realizes that they are now both in midair with no landing strategy. He crashes, but at least provides Weiss' landing cushion.
-->'''Weiss''': [[SarcasmMode My hero]].\\
'''Jaune''': My back!
[[/folder]]

[[folder: Web Comics]]
* An early strip of ''Webcomic/SluggyFreelance'' starts off with Riff and Torg talking about how Zoe has a date with this guy she has a huge crush on. Riff then mentions that he is going to visit his ex-girlfriend Gwynn at her apartment, which she shares with Zoe. Torg is surprised that Riff going to see her alone like that. Riff insists that they're not alone, that Zoe will be there... at which point he realizes that even though he was aware of both of these pieces of information he only just now realized that they were related.
* ''Webcomic/ElGoonishShive''
** Referenced, but [[AvertedTrope averted]] by [[http://www.egscomics.com/?date=2005-02-18 discussing the plan]] ''before'' trying it, allowing someone else to point out the flaw ahead of time.
--->'''Female Immortal:''' I hate being invisible and intangible; it feels like cheating.\\
'''Male Immortal:''' We can't exactly claim to be "everyday students" and expect to pass unnoticed in Elliot's house.\\
'''Female Immortal:''' We could pretend to be burglars! That would make sense, right?\\
'''Male Immortal:''' ... I don't think you've thought this through...
** Abraham. Almost ''everything'' he ever did and we know about, starting from an enchantment GoneHorriblyWrong for which he became infamous. He (among other things) swore to destroy every creature created by his botched enchantment, the Dewitchery Diamond, on the assumption that the Diamond would be used against curses, thus creating monsters. He hadn't accounted for the Diamond being used to rid people of relatively harmless conditions [[spoiler: such as Elliot's use of it to cure his GenderBender problem by creating Ellen, an (mostly) innocent OppositeSexClone]]. At one point, he claims he did everything he could to destroy the diamond, which failed. Within ten seconds, someone is able to think of something he didn't: ''Chuck it into a volcano''. Maybe it wouldn't work, but c'mon, it didn't even occur to him? Even if that didn't destroy it, nobody's going to be able to use it for a good long while.
* Webcomic[=/=]webgame ''Webcomic/WickedAwesomeAdventure'' points out how often this befalls adventurers in the course of escape and exploration.
** J.E.T. enlists the help of a wounded and unwilling Candimp to disarm a trap.
** Rhys solves a puzzle to access a new area of the Haunted House for exploration- opening a trap door, too.
* ''Webcomic/GirlGenius'' got a few examples. Like [[http://www.girlgeniusonline.com/comic.php?date=20060630 this]] [[http://www.girlgeniusonline.com/comic.php?date=20060703 guy]].
* [[http://www.giantitp.com/comics/oots0286.html This]] appropriately titled ''[[Webcomic/TheOrderOfTheStick Order of the Stick]]'' strip.
* ''Webcomic/FontesRants'': Fontes uses the Life Note, a {{parody}} of the ''Manga/DeathNote'' which creates a life form he writes in it, to create an AxCrazy MartyStu character. When he recovers after inevitably being knocked out;
-->'''Fontes''': ... I really shouldn't have made him able to summon firearms...
* ''Webcomic/{{Spinnerette}}'' has two groups trying to clone Adolf Hitler and Robert E Lee so they can lead their respective people again. Dr Universe, the scientist who promised to do the cloning, only did so because he knew the plan would fail, because nobody would follow a clone of Adolf Hitler or Robert E Lee.
* From ''Webcomic/SuperStupor'', [[http://www.superstupor.com/sust12282010.png this strip]], after Punchline explains why The Anarch's plan is really just [[SuicideByCop Suicide by Superhero]]:
-->'''The Anarch''': I may have made a slight error in my calculations.\\
'''Punchline''': When you were adding up the numbers, did you remember to carry the stupid?\\
'''The Anarch''': [[NoExceptYes Yes! ... no]].
* In ''Webcomic/SchlockMercenary'', the UNS tries to use a court case to trick a nearly [[DeusEstMachina all-powerful AI]] into admitting that he has been performing morally questionable actions (specifically, "disappearing" problematic people).
-->'''Kerchak:''' And then what?
-->'''Breya:''' I... haven't thought that far ahead.
-->'''Kerchak:''' I'll bet you a bushel of pureed bananas ''he has''.
* In ''Webcomic/TheWotch'', the Uricarn Demon killed all the other members of his species. He didn't think it through.
-->'''[[http://www.thewotch.com/?date=2006-02-27 Uricarn:]]''' I enjoy being your bit of controlled chaos. Beats just wandering aimlessly finding cheap thrills like I was doing after exterminating the rest of my kind... Which was kinda stupid in retrospect. Probably should have let myself grow up a bit before making that decision...*
* In WebComic/CommanderKitty, Nin Wah tries to turn herself over to the [[PoliceAreUseless Triple-I]] by teleporting herself to one of their ships... while CK is busy shooting them down.
-->'''[[http://www.commanderkitty.com/2010/04/04/i-can-goes-back-now/ Not one of your better ideas, kid.]]'''
* In ''Webcomic/QuestionableContent'', Angus, Marigold, and Faye get drunk together. Faye asks Marigold if she has ever dated anyone (she hasn't). She says that she think she has a chance with someone and looks at Angus as he returns to the couch. Faye, feeling incredibly awkward walks out and goes home. Thing is, Angus likes Faye (which Faye knows) and Faye may like Angus. Angus doesn't like Marigold like that, but she left them together drunk and alone. When Dora points out the obvious, [[http://questionablecontent.net/view.php?comic=1629 Faye has the appropriate reaction.]]
* In ''Webcomic/MenageA3'', during a Girls' Night Out Zii notices that every man in the bar is buying [=DiDi=] drinks and decides to intercept them. Problem is that she does so [[http://www.ma3comic.com/strips-ma3/for_your_own_good by drinking them down herself]], not the best move especially considering that [[StatuesqueStunner DiDi]] has at least 50 pounds on her.
* The first story arc of ''Webcomic/TheInexplicableAdventuresOfBob'' climaxes with Bob volunteering to save Ahem by fighting a monster. He reassures Voluptua: "Trust me, I know what I'm doing!" The monster appears, and it's a horrific thing with mandibles bigger than his whole body, and he realizes suddenly, [[http://bobadventures.comicgenesis.com/d/20060617.html "No I don't!"]]
* ''Webcomic/EightBitTheater‎'' - During their battle with the Lich King, the Light Warriors manage [[spoiler: to remove his soul from the earth orb - and then realize they have to get it back in him.]]
--> '''Red Mage:''' In other words, we've only succeeded in making the invincible king of death even ''angrier'' at us.
--> '''Thief:''' Y'know, I really hadn't planned this far ahead in the scenario. I presumed we were going to be dead about five minutes ago.
[[/folder]]

[[folder: Web Original]]
* In ''TheSalvationWar'', after the demonic general Abigor hears of the defeat of (most of) his cavalry attempting to charge a ridgeline with "cowardly mages throwing mage bolts, with mage-bars in the ground and silvery snakes in the ground that cut up demons and their steeds alike" (paraphrasing here), his plan for the second day of fighting is to extend his lines by thinning them -- by the time he was done, an almost-''fifteen-mile-long'' front! -- so as to outflank and envelope the enemy, while ordering massed use of demonic bolt "fire" to suppress the mages. Too bad he didn't realize that he would only be able see a small portion of the battle at any one time, and thus would have to keep riding back and forth along the lines, ''until he was already on the front lines in the midst of the carnage'', with multiple rockets headed his way... [[spoiler: they missed him, but he immediately and correctly intuited that he had been personally targeted]].
* [[Podcast/RiffTrax Kevin Murphy]] puts the exact phrase into the mouth of the [[Music/{{Anthrax}} Scott Ian]]-looking Geat who makes a spectacularly failed attempt to charge Grendel in the 2007 ''Film/{{Beowulf}}'' [=RiffTrax=].
* In ''WebVideo/DragonBallAbridged'' [[KidHero Gohan]] suddenly realized mid sentence that his decision to challenge [[TheBrute Recoome]] to a fight after Recoome had already wiped the floor with Vegeta, a much more powerful fighter, was a bad idea.
-->'''Gohan:''' I'm not going to back down. I might be younger than you, smaller than you, weaker than you, and ''much'' less experienced, but I learned more about peach farming than yo-I think this was a horrible decision.\\
'''Recoome:''' [[PreAsskickingOneLiner Recoome agrees]].
** In ''Dead Zone Abridged'', Garlic Jr's plan was to have his minions kill Kami to avenge his father...''then'' use the Dragon Balls to become immortal.[[note]]For the unfamiliar with the show, the Dragon Balls' power is tied to Kami so if he dies, they no longer work[[/note]] After Kami points this out, Garlic is honestly surprised and is glad his minions are "so incompetent".
*** Later on, he tries to kill everyone by summoning a portal to the Dead Zone... i.e. the perfect prison for an immortal like him. [[spoiler:When the plot is revealed to be a movie pitched by Krillin, the latter admits he had "written [himself] into a corner with the whole immortality thing"]].
* Early in ''WebVideo/YuGiOhTheAbridgedSeries'', [[DistressedDude Mokuba]] laments his poor foresight upon realising that using a BedsheetLadder generally only works if the sheet is long enough to reach the ground floor. Fortunately for him, [[NoFourthWall he's a cartoon.]]
* [[WebVideo/TheSpoonyExperiment The Spoony One]] puts this in the mouth of the main villain of ''Film/HighlanderTheSource'' when he gets the Quickening at the top of a tall tower.
* The plan that Leeroy's raid group comes up with for taking on the Rookery in the LeeroyJenkinsVideo ignores two key facts:
## Scattering the whelps of the Rookery only keeps them off you for a few seconds and will likely bring more to bear on you -- you really want to hatch as few of them as possible. Fear rotation is rather pointless in the Rookery anyway due to the rate at which the eggs respawn.
## The paladin ability Divine Intervention does not allow a protected character to use any skills and is very much wasted on mages (who primarily rely on skills such as AOE attacks) and has the added "bonus" of killing the paladin who uses it, removing a character with the ability to tank and heal from the general fight.
* ''MarbleHornets'': Half of what Jay does. For example, breaking into Alex's home. He drops his flashlight, and then runs into the Operator.
* InvokedTrope in ''[[DNAKpts4tv Death Note: The Abridged Series (kpts4tv)]]'':
-->'''Light:''' Wow, [[ArtifactOfDoom a book that drives people crazy when they touch it!]] (*touches the notebook*) Death Note? What is this like an advanced calculus notebook or something? I'm so gonna walk around and touch everyone with this and drive 'em... oh, right. I didn't think this one through.
* Happens in the first episode of ''DSBTInsaniT'' when Koden sends [[IneffectualLoner Killer]] to kick [[KidAppealCharacter Bear, Snake, Duck, and Balloon]] out of his house.
** Also in 'Beach Brawl' when Kerry impulsively throws Shovel at frozen Cell, thinking that would shatter him.
-->'''Bear''': "Even ''I'' saw that one coming a mile away."
* Lampshaded in [[http://occupyrichierich.tumblr.com/post/42699302738/richie-mboy-i-dont-think-you-thought-this this]] ''Blog/OccupyRichieRich'' post, where Richie demonstrates a button-activated safe-opening system - and the button is not protected at all.
--> "richie m’boy I don’t think you thought this through very well"
* At the beginning of Creator/AchievementHunter's ''GO!'' series, Geoff reveals that he would pay for a pizza party for every person who gets five wins. By the end of the twelfth episode, the scoreboard is reading 3/3/2/2/2 and Ray points out that, pretty soon, he's gonna be hosting back-to-back pizza parties. Geoff just looks at the scoreboard in total disbelief.
** After [[spoiler:Ray]] won the first pizza party, [[SubvertedTrope Geoff decided that the scoreboard would be reset every time someone in the group gets five wins]], which became effective the first episode after the first pizza party.
[[/folder]]

[[folder: Western Animation]]
* In one episode of ''WesternAnimation/JusticeLeague'', Copperhead attempts to gain leverage for an escape by jumping onto Hawkgirl's back, positioning his poison fangs near her neck, and ordering her to fly him out. She flies up a few hundred feet and stops. When Copperhead demands to know why, she notes that his threat is no longer as effective, since if he bites her neck she'll fall to the ground and they'll ''both'' die. "Didn't think this through, did you?" After she touches down, Green Lantern congratulates her on the bluff; her reply is a deadpan "Who's bluffing?"
** In another episode, Downpour, a pastiche of one of the Wonder Twins, tries to kill Comicbook/{{Aquaman}} by [[ShootingSuperman hitting him with a torrent of water]]. Aquaman [[NoSell just stands there]] with a [[FascinatingEyebrow raised eyebrow]]: "'King of the Seas', remember?"
*** Downpour's follow up wasn't particularly well thought out, either. He rushes up to Aquaman and punches him. [[PunchPunchPunchUhOh Ineffectually.]] Aquaman responds with a backhand slap that takes Downpour out instantly.
* ''WesternAnimation/LegionOfSuperHeroes'': [[spoiler:Alexis]] sics her personal robot on Superman, who [[CurbStompBattle immediately slices it apart with his heat vision.]]
-->'''Robot''': [[FamousLastWords Didn't think this]] [[TooDumbToLive through, did we?]] (''EyeLightsOut'')
* WesternAnimation/InvaderZim:
** Zim has this as a personality trait; as TheOtherWiki once described him, "Zim has a crafty sort of intelligence, but he tends to think precisely one step ahead of his current problem". For instance, Zim builds a [[TimeStandsStill stasis-field device]] in one episode which subsequently explodes, but the fireball is slowed by the stasis field until it's expanding at less than walking pace. However, it will eventually grow to the point where [[SphereOfDestruction it'll consume Zim's base along with the entire city]]. The Tallest might call back soon and Zim ''really'' doesn't want them seeing an embarrassing screw up like this (though they don't really give a crap). Basically Zim has to get rid of the explosion, do it in a way that doesn't destroy his base, and do it quickly. Zim's brilliant plan to handle this problem? Simple. He'll just ''cancel the stasis field'' under the assumption that once the field is canceled, the explosion will be gone forever. This true, but this will also ''annihilate his base and the whole city''. Despite being warned by his computer, and even his CloudCuckooLander sidekick, that this is a really, really bad idea, he goes ahead with it. HilarityEnsues.
** The Tallest also seem to suffer from this, resulting in conquered planets being turned into massive parking lots because they didn't know what they'd do with the planet after conquering. They also ordered enslaved races to build weapons for them, [[HilarityEnsues resulting in the Megadoomer needing a massive extension cord and cloaking everything but the pilot and said extension cord]].
* ''WesternAnimation/FamilyGuy'': In the episode "Blind Ambition", there is clip of one of Peter's (or both his) Siamese twin ancestors each fighting opposite sides in the Civil War. The one who fought for the Union killed the other, who continued decomposing until he was a skeleton. "Nope... Did not think that one through," he said to a bartender who asked about the skeleton.
* ''WesternAnimation/AmericanDad'': The episode where Francine gets poorly-aimed LaserGuidedAmnesia, she runs off to Burning Man with Hayley's boyfriend. This exchange happens when Stan meets up with Hayley at Burning Man:
-->'''Hayley:''' Mom stole my boyfriend!\\
'''Stan:''' Your boyfriend stole my wife! Let's get back at them by [[ParentalIncest dating each other!]] [[FridgeLogic Wait a minute.]] [[{{Squick}} Daddy didn't think that through.]]
** After Roger releases a bunch of murderers to make Stan's haunted house more scary, he admits that he never thinks things through.
* In the first episode of ''WesternAnimation/LazerTagAcademy'', Draxon Drear travels back in time to capture his ancestor who invented the Starlyte (which he used to travel back in time) and threatened to kill her if the authorities in the future did not surrender. The flaw in his plan should be self-evident.
* ''WesternAnimation/SpongeBobSquarePants'': For a copepod who goes to college and makes highly elaborate plots to get the Krabby Patty formula, Plankton can be a little slow when it comes to thinking ahead of his goals. For example, a robot made to look like a customer enters the Krusty Krab. Eugene Krabs, smelling an obvious trap, takes the place of the register. To his astonishment, the robot just asks for coral bits and even pays him money after it's given its order. Suddenly, Plankton, who somehow managed to hide ''inside'' the dollar bill (even for someone his size, there must have been some {{hammerspace}} in there), pops out and gloatingly orders Krabs to hand him the secret formula. Krab's response: "Or what?" Plankton: "I don't know. I never thought I'd get this far." Krabs: "Well then, allow me to suggest your next move" (flushes him down the toilet).
* ''WesternAnimation/TheFairlyOddParents'': In "Timmy's Secret Wish!", Foop, having [[EvilLawyerJoke become a lawyer]], exposes the secret wish Timmy made to freeze the world in ComicBookTime so he would be able to keep Cosmo and Wanda forever, as part of his latest plan to get rid of Poof, as, since Poof only exists because of a wish Timmy made, he would be undone like all of Timmy's other wishes. Foop succeeds, but it's only afterwards that he remembers that, as Poof's EvilCounterpart, ''he'' would be undone as well.
* The ''WesternAnimation/JimmyTwoShoes'' episode "The Big Drip" has [[LouisCypher Lucius]] destroying every washroom in Miseryville to torment Jimmy during a PottyEmergency... including his own.
** And pretty much any plan Jimmy and Beezy devise (alone or together) without outside input.
* ''WesternAnimation/AvatarTheLastAirbender'': Zuko, such as when he kidnaps Aang in the ''North Pole'' (alone, in a blizzard, with the closest fire nation ships all being hostile) in the first season finale or when he tried to steal Appa from Lake Laogai. [[CharacterDevelopment He gets better, eventually]].
** Zuko's so bad with it that it's contagious.
-->'''Zuko:''' I thought you thought this through.\\
'''Sokka:''' I thought you told me it's okay not to think everything through!\\
'''Zuko:''' Maybe not everything, but this is kind of important.
** In ''WesternAnimation/TheLegendOfKorra'', this is a notable character trait of Korra's for most of the first season's run. And [[MagnificentBastard Amon]] takes advantage of this at every turn.
* The BugsBunny cartoon ''Jack Wabbit And The Beanstalk'' has Bugs challenging the giant to a duel. "Take twenty paces, toin, and fire. Got that, shorty?" As the giant takes his paces, he disappears into the horizon and Bugs thinks he's outsmarted the giant. But then the giant reappears over the other horizon--the twenty paces were enough to circumnavigate all the way back.
* From the "Dog Of Death" episode of ''WesternAnimation/TheSimpsons'':
-->'''Homer:''' I've figured out an alternative to giving up my beer. Basically, we become a family of traveling acrobats!\\
'''Marge:''' ... I don't think you thought this through.
* From the "Her Parents" episode of ''WesternAnimation/AdventureTime''
-->'''Jake:''' Nah... That could never happen.\\
'''Finn:''' You didn't think this through enough. IT COULD HAPPEN!
* Turned into a ''RunningGag'' with Mojo Jojo in ''WesternAnimation/ThePowerpuffGirls''. To the point where when a spree of robberies occurred in Townsville, the girls quickly ruled him out as a suspect because it was too well thought out.
* WesternAnimation/WackyRaces - Every single time DickDastardlyStopsToCheat. It's never enough that he is ALWAYS miles ahead of every other racer, he not only has to stop to lay a trap, but also stays behind to see the payoff, which ALWAYS puts him in last place. The most absurd example was the episode where he got stuck in the mud, and pulled out by a farmer with a donkey. He decides to buy the donkey, thinking that the farmer will no longer be able to pull the other racers out. Never mind that 1) almost half the racers have some gimmick that allows them to get out on their own, including a dragon that can dry it up completely, 2) the farmer OBVIOUSLY has several beasts of burden besides the one he sold and 3) Just what the heck will he do with a frickin' donkey?!
** 4) after Dastardly's first opponent (Penelope) crossed the mud (with help from the farmer), he actually waited until all others passed before trying to resume his racing.
** In answer to 3, he [[spoiler:rode the donkey to the finish line because the donkey destroyed the Mean Machine]].
** Lampshaded in the unaired pilot for ''Wacky Racers Forever'', where after Muttley pointed out that they're close to the finish line, Dick pointed out that [[ContractualGenreBlindness they're villains, and thus, have to cheat in the race]].
* In ''WesternAnimation/AvengersEarthsMightiestHeroes'' Absorbing Man occasionally absorbs things he really shouldn't. When fighting the Hulk as metal, he absorbs rock. The Hulk promptly breaks his arms off. The metal form might not have let him win, but was at least keeping him in one piece. Much later he absorbs Mjolnir, and Thor reveals that he can now control Absorbing Man just like he does Mjolnir, and starts hitting people with him.
* In an episode of ''WesternAnimation/{{Rugrats}}'' the babies imagine shrinking down and traveling into Chuckie's stomach to take out a watermelon seed he accidentally swallowed. Angelica however reveals her intention to actually water the seed so it grows and causes Chuckie to explode. She succeeds and gloats evilly, until Tommy points out it's going to explode ''[[OhCrap with her inside it]]''.
* From ''WesternAnimation/AquaTeenHungerForce'' when Frylock rebuilds Carl by giving him a military suit and arming him with weapons of mass destruction.
-->'''Frylock:''' I give you the ultimate in military hardware complete with laser cannon, indestructible titanium exoskeleton and motion-activated plasma pulse rifles.\\
'''Shake:''' And you're gonna plug him in!?\\
'''Frylock:''' You're right. Damn, what the hell was I thinking?
* In the ''WesternAnimation/{{Thundercats 2011}}'' episode "The Forest of Magi Oar," the young hero Lion-O begins to recognize and {{lampshade| Hanging}} his own lack of forethought. When he uses his gauntlet's {{grappling hook| Pistol}} to latch onto a retreating GiantFlyer Viragor, Lion-O has just enough time to realize "[[OhCrap maybe this is a bad idea]]" before he gets violently dragged along for the ride. Shortly thereafter, he faces down the charging BigBadassBirdOfPrey after [[SheatheYourSword tossing his weapons aside]]. Again, he muses, "[[ThisIsGonnaSuck probably another bad idea]]," seconds before it grabs him in its talons. The latter gamble does manage to [[SubvertedTrope pay off]], since, on a hunch [[spoiler: Lion-O is betting Viragor proves DarkIsNotEvil]].
* In an ''WesternAnimation/{{Animaniacs}}'' ''WesternAnimation/PinkyAndTheBrain'' short Brain devises a plan to infiltrate Fort Knox and make off with all of its gold. The duo actually succeed in getting into the vault, but Brain forgot about them having to ''carry'' the gold, and since they're mice you can see where this is going.
* In one episode of ''WesternAnimation/DuckTales'', the Beagle Boys manage to get inside the Money Bin and trap Scrooge outside. When they call Glomgold to gloat, Glomgold points out that they have no way to transport the money ("What are you gonna do? Carry it in your wallets!?") and that Scrooge will have an army ready to take his Bin back.
* In the ''WesternAnimation/SouthPark'' episode "Summer Sucks", after fireworks are banned, the Mayor attempts to glorify the use of ash snakes with a giant sized one for the Fourth Of July. It works and creates an enormous display of ash... and keeps going... and going. The now somewhat nervous Mayor asks the creator when it will stop, he explains that he has no idea since he never made one this big, leading him to quote this trope to the exasperated Mayor.
* In ''WesternAnimation/DextersLaboratory'', this was very often one of Dexter's fatal flaws despite being a genius. Justified seeing that he was only about eight years old, and so he was bound to make mistakes.
* In Disney/MeetTheRobinsons this is pretty much Bowler Hat Guy's main defining characteristic.
* In ''WesternAnimation/SymBionicTitan'', In order to contain [[spoiler:a mutated and violent Ilana]], Octus traps her inside the barrier that is his body. However, he failed to consider that it would allow her to attack his "head", and pretty much names the trope.
* ''PhineasAndFerb'': Doof tried to drill a tunnel to China and forgot about the lava from the center of the Earth.
* In the WesternAnimation/TransformersAnimated episode "Sari, No One's Home", Sari gets trapped alone in the Autobot base with Mixmaster and Scrapper. Unable to contact the Autobot team (her cellphone was broken), she decks herself out with a helmet, roller blades and a hockey stick to drive them out herself. As soon as the eight year-old human attacks the two story robot, [[NoSell her hockey stick breaks.]]
-->'''Sari:''' Okay. That's as far as my plan got.
* ''WesternAnimation/RandyCunninghamNinthGradeNinja'': In ''The [=McHuggers=] Games'', the Ninja stole a [=McHugger=] from Hannibal [=McFist=] before the product was available in stores. Knowing the Ninja, like every other highschooler in Norrisville, would be attracted to the publicity event created to advertise the [=McHuggers=], Viceroy sent a robot to the event and programmed it to attack whoever was wearing [=McHuggers=], thinking the Ninja would be the only one. He forgot that, given the publicity campaign's goal, the spokesman would be wearing one as well.
* In an episode of ''XiaolinShowdown'', Omi wishes to use the [[TimeTravel Sands of Time]] to return to the past. Only, his older self took it when he returned to the future. So Omi uses an alternative, tried-and-true method that lets him effectively travel forward in time ([[HumanPopsicle freezing himself for a few decades]]) so that he may retrieve the Sands of Time from his older self. You may have spotted the flaw in this plan already: [[spoiler:with Omi frozen, there was no Omi left to grow old.]]
[[/folder]]

[[folder: Real Life]]
* Most people make this mistake in everyday situations when they know the results of a missed variable can be ignored or worked around (e.g. if you reach for a tool that you forgot to prepare, just get up and retrieve it). Bad things tend to happen only when too many of such mistakes line up and cause a chain reaction.
* A rather better military example would be Project Pluto, the supersonic low-altitude nuclear-powered nuclear ramjet missile developed by the U.S. military (the fact that they seriously considered building that thing counts already). Project Pluto's real problem was that it was overtaken by [=ICBM=]s during its development. Aside from the difficulty in test firing it (which wasn't as crippling as it sounds, it might be an environmental disaster on wings, but this is during an age predating the green movement, meaning that a bit of isolated water in the Pacific would do), the project had a serious chance to turn out as a practical NukeEm to hell option. Its just that [=ICBM=]s are more practical, being faster, cheaper and harder to intercept; they may not irradiate such vast swaths of enemy land by merely flying over them, but once the major cities are gone, that hardly matters anyway.
* Australia's problem with the Cane toad. Because of Cane beetles destroying sugar cane crops, a bunch of Cane toads were imported to get rid of them. Only problem was that the toads couldn't even jump that high, so they ended up being unable to eat the beetles that were on the tall stalks... which caused them to eat everything else. And then they started infesting and taking over... combined with how they're highly poisonous and can poison any animal that eats them. Yeah, that solution was not exactly the best thought out.
** It doesn't help that cane beetles and cane toads aren't active at the same time of day, so they don't ever even interact.
*** Pause to think about that for a second. They found an animal ''too poisonous for Australia,'' home to the most venomous spider known (the Australian funnel-web spider), and even the duck-billed platypus has a venomous spike in its webbed feet.
* Another Australian one: The Murray River was destroyed in an attempt to bring over European farming techniques without realising that Australian soil was ill-suited to the endeavour. Clearing of trees for land led to salt buildup, which poisoned the water and ended up clogging the river.
* And yet another: Despite already knowing that Australia is the driest continent in the world (seriously, check out the sheer amount of ''desert'' there is), no government there had a sufficient water-saving plan aside from the restrictions. This came back to bite them in the arse when the country was engulfed in an extreme drought, the likes of which had not been seen for the past several centuries. Of course, now they have the exact ''opposite'' problem...
* The [[http://en.wikipedia.org/wiki/Lake_Peigneur#Disaster Lake Peigneur disaster]] was caused by someone drilling for oil through a lake into a salt mine. Admittedly, they knew not to drill through the salt mine and just messed up when they were figuring out where to drill, but still.
* During WW2, the Russians [[ActionBomb strapped explosives to dogs]] trained to run at tanks. Once the tank ran over the dog, the pressure-activated explosives would total the tank. The only problem? They trained the dogs using Russian tanks made to look like German ones. But Russian tanks used diesel engines; German tank engines used petrol. When in doubt, they went with what ''smelled'' familiar. [[HoistByHisOwnPetard Hoist by their own petard]] indeed.
** It killed half the canines in southeastern Russia, which made herding and various other jobs a dog would do even more difficult. Eventually there were breeding programs, but for a couple years dogs seemed to be extinct in Moscow.
* A salesman showing reverse searching (which was a search for what people were searching the internet for) decided he would use "toys" as the keyword. [[TheInternetIsForPorn Apparently, he didn't realize until too late what kind of toys people search the internet for from the privacy of their own homes...]]
** Considering RuleThirtyFour, it would have been smarter to just skip the demonstration altogether.
* Quaker Oats buying Snapple for $1.7 billion. Unlike every other drink in Quaker's line-up (including, for instance, Gatorade), Snapple has to be refrigerated. It was only after the deal had gone through that Quaker realized that it had a shipping fleet of exactly zero refrigerated vehicles. Refrigerated distribution outlets soon realized this as well, and colluded on a high price to deliver the Snapple. Eventually, Quaker sold it for $300 million to another company, long after Snapple's trendiness had faded.
* Nazi Germany had a problem: with the US being officially neutral but unofficially supporting the Allied war effort, German u-boats could not be used to their full effectiveness in the Atlantic. Japan attacks the United States and war breaks out, and Hitler thinks this solves his problem as he can declare war on the US because Japan is an ally, and thus finally give his naval forces the freedom they need to effectively cut off Great Britain. Of course, this also means the single largest economic and manufacturing power on the planet now doesn't [[MuggingTheMonster have to pretend to play nice either]].
** Another WWII example is that Japan attacked the US trying to scare them out of the war. [[AwakeningTheSleepingGiant We all know how that turned out]].
** Yet another WWII example is the study the Japanese commissioned on US industrial production in 1940, presumably hoping to avert this trope. The discovered, to their delight, that the so-called industrial giant of the USA was actually producing only slightly more than Japan. Huh, they think, maybe the Americans aren't an industrial powerhouse after all...unfortunately, what they failed to realize was that Japan had been at war for 3 years and was going flat-out economically, whilst the USA was at peace. Wah-wah.
* This was pretty much Benito Mussolini war carer. He is even sometime blamed for Hitler losing the war.
* Criminals. This tends to happen to them a ''lot''. In example:
** A few would-be ATM thieves in South Africa decide to use explosives to open up an ATM. Once the bomb goes off, the money would be theirs for the taking! But, somewhere in thinking how awesome it would be to blow up an ATM with a bomb, they forgot to make an important consideration. Namely; ''[[OhCrap paper money tends to burn]]''. HilarityEnsues.
** There have been several cases of people walking into a business, filling out a job application with their real name, address, etc., and '''then''' holding the place up at gunpoint. Of course, it doesn't take too long for the police to find them.
** One example was a bank robber who decided to rob a bank, that was across from the FBI headquarters, ON PAY DAY. Oops.
** Another robber went up to a bank with a stick-up note... written on the bottom of his pay slip, which had his name, address, postal code, and telephone number on it. Of course, he doesn't compare to the robber who held up the bank coming right from his work at a construction site... still wearing his hard hat, which had his name on it. Neither of them are quite as stupid as the criminals who decided to ''draw masks on their faces with black marker.''
** Another robber had the [[SarcasmMode absolutely brilliant]] idea to rob a gun shop. He found out the hard way that the guns are ''not'' for display purposes only. Not only did he rob a gun shop, but he walked past a marked police cruiser to get there. They say he was so surprised at seeing a cop that he opened fire. Six customers and the cop drew and 4 of them returned fire. [[TooDumbToLive He did not survive]].
** Then there was the time a robber tried to rob a shop, whilst wearing a crash helmet. A crash helmet that had ''his name '''emblazoned across the front'''''.
* Official policy of communist states to deal with disaster? Issue a nationwide bulletin that [[SuspiciouslySpecificDenial absolutely nothing has happened]] [[BlatantLies and everything is fine]], and censor any attempt to bring it to the public's attention. Well the public still becomes aware of it, but by that time, it's too late to do anything about it.
** Biggest example: The Chernobyl Disaster. It was one of many things that led to TheGreatPoliticsMessUp.
** The resultant policy of Glasnost the Soviet Union enacted after the disaster is another example, but in the reverse. Turns out, when you can't even feed your own people, enacting a policy of total transparency with the press is not such a good idea after all.
* The Mongol Invasion of Japan. Kublai Khan was in such a rush that he ordered the Chinese boat builders to make a huge fleet (a fleet second only to the invasion fleet that launched the Invasion of Normandy) within a single year. The Chinese laborers had to supplement the sea-worthy boats with river boats that had no keel, and thus were unworthy for sea travel. Bad enough when you are crossing an ocean, even worse when that ocean is prone to violent storms and typhoons. The now-famous ''kamikaze'' led to the single greatest loss of life in a disaster at sea in recorded history, with many of the over 3,000 ships sinking with most of their crew.
* Italian general Pietro Badoglio in UsefulNotes/WorldWarI expected the Austrians to possibly break through in the Caporetto sector, and had prepared an ambush with tons of artillery to annihilate the Austrian troops, then gave the artillery commander orders to ''not'' open fire unless he ordered him to, and returned to his headquarters to wait for the enemy offensive. When the Austrians did break through at Caporetto, he gave the order... only to discover that the Austrian preparatory shelling had interrupted the phone lines, the noises of the battle covered his sound-based signals, and the heliograph's signals were blocked by the fog. The Austrians realized there was a trap only when they saw the guns and the artillery commander surrendered to them. Since then, in Italian, 'Caporetto' is synonymous with [[CurbStompBattle 'utter and complete defeat']].
* In 2011, a twenty-year-old woman came forward claiming to have been knocked up in 2010 by the then-sixteen-year-old Music/JustinBieber, and attempted to sue him for compensation. If she lost the case, she could be tried for fraud. [[MortonsFork If she had won the case, she would have been admitting to]] ''[[MortonsFork statutory rape]]''. Baby, baby, baby, ''no''.
* ''Website/NotAlwaysRight'': [[http://notalwaysright.com/lock-blocked/26978 This kid]] didn't quite realise that a locked padlock that he tried to pinch couldn't be, well, unlocked without a key!
** ''Website/NotAlwaysWorking'':
--->[[http://notalwaysworking.com/the-colour-derple/29856 "To get to the colour blind test, just go outside and follow the green signs until you see a red building. Go through the purple doors, just past the blue ones."]]
* The 1939 IRA Christmas Raid on the Phoenix Park Magazine in Dublin. After subsisting on a crate of ammunition here and a crate of ammunition there for years the IRA decided to end its ammunition problems once-and-for-all by robbing the Irish Army. Which went surprisingly well for them, netting thirteen truckloads of ammunition with no shots fired. What they had neglected to consider was exactly how they were supposed to hide thirteen truckloads of ammunition. Most of the ammunition was recovered within four days leading to a slew of arrests.
* In the late 1990s, [[DisneyThemeParks Disneyland]] was developing a new ride called the Rocket Rods, a high-speed thrill ride that would take riders beyond speed of most roller coasters. Sounds cool, right? Well, they were going to use the track that was originally for the People Mover, a slow, leisurely trip around Tomorrowland. The decision was made to use the track as is and build the new ride on it. As a result, since there were no banked turns, the ride vehicles would get up to speed, and then have to slow down to make the curves, and there were a lot of them. In addition, the track itself was not built to handle high speeds and began to deteriorate. Between this and the ride's ''very'' buggy control program, it was spending just as much time shut down as active, and was closed down in 2000, after only two years of operation. The thing is, it might have been successful if Disney officials had taken the more costly route of tearing the track down and building the one they really needed, with banked turns and able to handle the stresses it would be put under. As it is, the Rocket Rods stands as a monument to the poor planning and management that plagued Disneyland around the Millennium.
* The infamous ARMM of Usenet. Unleashed on March 30, 1993, ARMM was a bot that attempted to automatically flag automatically generated messages for deletion. Notice the lack of the word "other" in there. That's right, ARMM triggered on itself, producing a recursive explosion of nested cancel messages that clogged lines and servers alike, with a confirmed kill of at least one poor mailserver that couldn't handle the traffic. As this was the Nineties, the gigantic recursive messages actually cost users extra money thanks to per-line charges on their Internet!
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