History SpannerInTheWorks / AnimeAndManga

*** And, of course, the ultimate one: three Zeon soldiers go to Side 7 to investigate goings on in there and discover the Federation building Mobile Suits there. Had they not attacked the factory, the Colony wouldn't have been destroyewd and Amuro would have NOT been in the right place and time to hop into the Gundam that his father built...

* ''Manga/{{Monster}}''. [[spoiler:The perfect suicide that Johan planned as the end of his GambitRoulette is ruined when an alcoholic townsperson angrily shoots him in the side of the head before Dr. Tenma can kill him.]]

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

** In the WholeEpisodeFlashback of manga chapters 921-924, Shinichi himself was one of these ''at the age of four''. In his attempts to befriend a just as young Ran in his new daycare, he briefly caught [[NightmareFace a weird]] [[OhCrap expression]] in the face of the daycare worker in charge. He mentioned that as well as other details in front of his parents in what seemed to be just a display of childish jealousy... this but allowed his GuileHero dad Yusaku to realize that [[spoiler:the teacher and his IllGirl wife were planning to kidnap Ran and raise her as the ReplacementGoldfish of their runaway daughter]]. Yusaku alerted the police (including Ran's ActionDad Kogoro), had [[spoiler:the wife and her brother/accomplice arrested]], convinced [[spoiler:the teacher to turn himself in willingly in exchange for being reunited with the missing daughter, and Ran was ultimately saved]] -- all because [[ChildProdigy Shinichi]] made his first deductions right in the perfect moment.

*** Domon Kasshu. Suffice it to say, he's a thorn in the side of anyone who ever has a plan in this series (including, sometimes, [[NiceJobBreakingItHero people on his side]]). Examples include showing up in Shinjuku just as Master Asia is putting his EvilPlan into motion and [[spoiler:being in love with the person Ulube selects as the core unit for the Devil Gundam: via an AnguishedDeclarationOfLove, he managed to break through Rain's brainwashing and release her, with ThEPowerOfLove fueling the God Gundam's ultimate attack that let them destroy the Devil Gundam forever and ever.]].

* In ''Manga/AnatoliaStory'', Queen Nakia needs a special girl's blood to perform a powerful BloodMagic that will kill her stepson Kail and give her the chance to make her own son Juda the heir to the Hitite Empire. Too bad that the girl she brought into Hattusa as her prospect HumanSacrifice, Yuri Suzuki, turned out to be a naive but very fast-learning PluckyGirl who decided to fight back to protect herself, then became the partner and concubine of the same prince Nakia wanted to murder, and she not only ended up becoming Nakia's strongest rival but also one of the most influential people in the nation.

* ''Anime/MawaruPenguindrum'':
** [[spoiler: Ringo Oginome]] pretty much tells [[spoiler: Shoma Takakura]] that he became one for her [[spoiler: "Project M"]] in episode 11. This, because [[spoiler: Shoma is the first person to question said "Project M", in which Ringo wants to reach almost all the possible extremes to bear the child of Tabuki-sensei since it means [[MySiblingWillLivethroughMe she'll live the life of her dead older sister]] Momoka; among other things, Shouma tells Ringo that she's herself and ''not'' Momoka, which later makes her think twice in regards to having sex with a {{Love Potion}}ed!Tabuki.]]
** There's another one whose spanning "powers" act on a bigger scale: [[spoiler: Masako Natsume]].[[spoiler: In her backstory episode, we find out that she doesn't want to be used by Sanetoshi at all and only goes along with his plans resentfully to keep her little brother Mario alive. Later on, she refuses to burn her half of the Destiny Diary, which serves as some sort of seal on Sanetoshi's power; the entire diary does get burnt to bits by Episode 23, but Masako's refusal holds him off long enough for Ringo to learn the Fate Transfer spell.]]

* ''Anime/AshitaNoNadja''

* ''Manga/KatekyoHitmanReborn'' has a mid-level mechanic incidentally named Spanner that performs a HeelFaceTurn along with [[spoiler:Irie]] in an effort to take down the Future Arc's BigBad Byakuran using his technical knowledge of the base and Millefiore. It would have slightly more effective if Byakuran wasn't an ultimate [[TheChessmaster Chessmaster]] and the in-series King of XanatosSpeedChess forcing the epic battles, struggles and hardships just for his own amusement.

* ''Manga/MahouSenseiNegima'':
** Nodoka, Kazumi and ''especially'' Chisame derail [[spoiler: Kurt Godel's ThanatosGambit]], because [[spoiler: when Negi goes OneWingedAngel on him after he reveals what happened to his DoomedHometown, Nodoka and Kazumi hold him in place, and then Chisame slaps him back to sanity.]]
** And it's not the only one. [[spoiler: Natsumi Murakami is the owner of an artifact which hasn't been found/used/invoked in ''centuries'', obtained from her Pactio with Koutarou. Said artifact is basically an InvisibilityCloak... and she uses it to bring ''a whole rescue team'' to the place where [[ApocalypseMaiden a captive and unconscious]] [[AntiMagic Asuna]] is about to be used by Fate to rewrite the whole Magical World. Fate's [[OhCrap horrified]] face when he sees what happened is ''priceless''.]]

* [[spoiler:Midori Sugiura]] from ''Anime/MaiHime'' threw a big wrench in the BigBad's plans to take over/destroy the world through the "winner" of the [[ThereCanBeOnlyOne battle royale]] by enlisting the help of the most unlikely of characters: [[spoiler:Miyu the RobotGirl, whom she located and rebooted. More importantly, she lets her ''keep'' her memories of Alyssa, deciding to trust in that. More than the right decision considering this allowed what seems to be the ''spirit'' of Alyssa to activate Miyu's strongest mode and ''smash the pillars'' containing the souls of those sacrificed, with the side effect of freeing the previous Crystal Princess...]]

** [[spoiler:Ironically, Tobi himself became a spanner in Black Zetsu plans with his reluctance to resurrect Madara and a wish to take control of the Moon’s Eye Plan since Black Zetsu wanted that reincarnation Indra in the person of Madara has completed the plan, that forced him to use Kabuto in order to revive Madara as zombies in first place. Also his HeelFaceTurn and his a wish help team 7 becomes a spanner to Kaguya the plan to get rid of them and ultimately becomes the cause of her defeat and re-sealed.]]

** When one of the boss monsters comes back from being defeated in battle against the Hero, he complains that the items provided for him were all more useless than the last. While the first couple instances likely ''were'' the Princess, as evidenced by being inside of sacks made of Ghost Shrouds, monsters the Princess regularly hunts for materials. However, as the list goes on, one after another the Demon King's generals, and even the Demon King himself, realize that ''they'' were responsible for the items being useless, such as replacing a bag full of grenades with avacados out of fear the Princess would tamper with them, or a robot designed to resemble the Princess being redesigned into uselessness because the Princess complained.

* ''Anime/DennouCoil'' protagonist Yasako is revealed to be this in the final episode. [[spoiler:When Yasako was about seven years old, she stumbled into a hidden Space being used to help a girl her age, later known as Isako, cope with the death of her older brother. Yasako encounters a simulation of this brother and her affection towards him sparks Isako's insecurities and fears of losing him, resulting in the creation of Miss Michiko, which is the cause for many problems throughout the series]].

*** Going to Punk Hazard destroyed many villains' ongoing plans. It not only derails Doflamingo's 10 year rule, but also devastated Big Mom's, Shogun Orochi's as well as Kaido's plans. Big Mom could never have [[spoiler:laid hands on Sanji]] if not for the trip to Dressrosa, which in turn [[spoiler:bolstered Luffy's own reputation as a prospective Emperor]] when Luffy went charging in to the rescue. Orochi and Kaido's enemies were there in Punk Hazard itself. As they rescued Kin'emon and Momonosuke, they also [[spoiler:revitalized Wano's resistance movement against the tyrannical Orochi, and Momo himself is revealed to be the son of Oden, the transcriptor of the ''Roger Pirates'']]. Also they accidentally saved Zou from being destroyed by Jack, only because Kin'emon and Momo stated it as their destination. The red Poneglyph in Zou in turn provided the most important clue to the route to Laugh Tale. It's safe enough to say both Wano's resistance and Luffy's quest would have failed]] [[UnwinnableByMistake completely by accident]] if Luffy didn't decide to step on the most dangerous island to report on the distress call.

** Lola from Thriller Bark; During Thriller Bark, she supplies Luffy with the shadows that allow him to pummel the giant zombie Oars, and though that doesn't destroy Oars, it does weaken him enough for the Straw Hats to finish him off. Then, before they part, she gives Nami a Vivre Card that apparently belongs to her mother; [[spoiler: In Totland, it's shown that ''Big Mom'' is Lola's mother, and that card is full of Big Mom's SoulPower, allowing Nami to control the {{Animate Inanimate Object}}s also created by Big Mom. In fact, by leaving Big Mom's territory, ''Lola disrupted an ArrangedMarriage that would have allowed Big Mom to become Pirate Queen!'']]

* Although the events of ''Manga/CardcaptorSakura, Manga/TsubasaReservoirChronicle'', and ''Manga/XxxHoLic'' are among the most complex and [[GambitPileup densely gambited]] known to man, ''none'' of the respective [[TheChessmaster chessmasters]] of the former two expected Yukito to fall in love with Touya instead of Sakura. The gambit ruling the latter one ''did'' anticipate the YaoiGuys - but apparently failed to anticipate a ''heterosexual crush'' from one of them.

** Ironically, Lelouch could count as ''his own'' Spanner: on multiple occasions, his attachment to his friends (mostly Suzaku or Shirley, but '''''especially''''' his sister Nunnally) have caused him to make moves that jeopardize his plans or even ''the entire rebellion'' he leads. The first occurrence in R1 is where he [[spoiler: lets Villetta live, because he thought she was no danger to him]]. When was that? Second episode. The big ones are where he [[spoiler: ignores his own unstable Geass, leading to the death of Euphemia as he geasses her into becoming a GenocidalManiac and then has to shoot her dead to stop her]], and where he abandoned his followers for his kidnapped sister shortly afterward which ''greatly'' weakened their position, his trait continued on in R2. This came to the logical conclusion [[spoiler:when his RoaringRampageOfRevenge for the murder of Shirley, carried out against a cult whose members included scientists and children, which ended up being a large part of Prince Schneizel's efforts to turn the Black Knights against him - the centerpiece being the fact that their beloved leader possesses a MindControl eye and quite possibly forced them all into obedience (he didn't, probably because he's smart enough not to misuse a power that only works once).]]

** On the Niseko GP, Bootsvorz's first attempt to crash out the car gets ruined by Hayato's sudden pit entry for a set of rain tire. An unexpected rainfall that follows causes him - running on slick - to spin out.

* In ''[[Anime/GoLion Beast King Golion]]'', Honerva's plan to take down Altea by [[spoiler: killing Shirogane]] falls victim to ''two'' spanners- one was Kurogane in Red Lion coming up with the idea [[spoiler: to push the Deathblack Beastman Galcia into some magma]], and when Galra attacks again before Altea could train a replacement, [[spoiler: Fala takes Blue Lion]].

** In the first, Aphrodite had devised a pretty good back-up plan shall he lose his fight with Shun: he anticipated the Saints would try and have someone keeping him busy while the other continued to run, so he planted his poisonous roses on the stairs behind his temple to act as DeadlyGas. By all rights, he had won with mocking ease, ''and'' it was about to work since Seiya fell for it in his despair and urge to go forward... [[spoiler: But then, Seiya's mentor Marin showed up. As a Female Saint, Marin had to wear a CoolMask - so she put it on Seiya, which allowed him to recover from the poison even when it poisoned ''her'' instead. As he wasn't breathing poison anymore ''and'' he saw his beloved mentor collapsed, Seiya gained enough physical strength and HeroicWillpower to destroy the roses, clearing his path to the top and towards the BigBad.]] [[spoiler: And by the way, Shun defeated and killed Aphrodite anyway.]]

* ''Anime/SamuraiChamploo'':
** Mugen is a prime example. In the first episode, Mugen dispatches a horde of mooks and then approaches their boss, who then explains to Mugen how he is the son of the town's corrupt governor. Any attempts to harm the son of an important official will be a death sentence. He then confidently asks Mugen if he got all that. Mugen responds with, "Not a word," and then attacks him.
** Mugen also manages to thwart a hostage situation simply because he was only interested in getting his kicks fighting and couldn't care less about the hostages.
* ''Anime/TenchiMuyo'':
** InspectorOblivious Mihoshi actually has a distinguished service record with the Galaxy Police, but the backstory indicates it's largely a result of her bumbling in and causing too much chaos for any dastardly plan to hold up. In the original {{O|riginalVideoAnimation}}VA, ''Anime/TenchiMuyoRyoOhki'' it was suggested she actually had had a mental breakdown from being overworked which turned her from a top cop into a comic ditz -- as hinted by Kagato's comment about her past exploits. He should know, since Mihoshi's meddling [[spoiler: led to the release of Washu, whom [[CrystalPrison he held hostage]] ''in a PocketDimension inside Kagato's CoolSpaceship that no one but Washu and Kagato knew of'', and yet Mihoshi somehow got there with ease.]]) Later versions, though, lack this detail and instead are all just lucky enough to be teamed up with Kiyone, who usually can get the job done in spite of Mihoshi. Yet as evidenced by her enormous reports, Mihoshi still seems ridiculously thorough.
** In ''Anime/TenchiInTokyo'', there are ''three'' of these.
*** Washu, because the villains always tend to underestimate her, and in this case this lets her lock herself in her laboratory to decode the BigBad's plans without anyone disturbing her, which she manages to do almost flawlessly.
*** The second spanner is Sasami, because [[spoiler: Yugi got distracted by her desire to keep her out of her schemes since she's her MoralityPet]]. This was pointed out by TheDragon ''twice'', and it never stuck.
*** The third and biggest spanner is Sakuya, who [[spoiler:despite being Yugi's "shadow", in the end turns out to be more independent than she should've been, and ends up breaking through a LotusEaterMachine that keeps Tenchi away, snapping him out of it and letting him talk her down]].
** ''Tenchi the Movie: Tenchi Muyo in Love!''
*** In the first Tenchi movie, ''Tenchi Muyo In Love'', Washu's plan to capture KAIN and prevent him from killing Achika gets derailed when KAIN decides [[TakingYouWithMe if he goes, he's taking Achika with him.]] It gets worse when Noboyuki is dragged along, too.
*** To that end, KAIN's own plan is derailed when he [[KickTheDog decides to toy with both Achika and Noboyuki]]. [[ViolentlyProtectiveGirlfriend Achika]] seeing Noboyuki's beaten body and how the poor guy is ''still'' devoted to trying to make her happy even in his state is enough to awaken her power when she goes into a TranquilFury.
* ''Anime/MazingerZ'', ''Anime/GreatMazinger'', and ''Anime/{{Mazinkaiser}}'' would be so much more different had [[JokeCharacter Boss]] not interfered with the baddies plans. To clarify:
** In ''Anime/MazingerZ'', thanks to [[MemeticMutation Brocken]] [[SugarWiki/FunnyMoments Ball]], Koji is able to rescue the kidnapped civilians. Not to mention the fact that in the same series, he saved Koji's life several times, gaining Koji's respect in the process. And in the ''Mazinger-Z versus Great General of Darkness'', as a squad of Mykene Warrior Monsters are trashing Mazinger-Z he suddenly interfered. He only deterred them for several seconds, but those seconds were all that [[spoiler:Tetsuya needed to intervene with Great Mazinger and save Kouji's life. And because Kouji did not die, he could help to save the world in ''Anime/GreatMazinger'' and ''Anime/UFORoboGrendizer''.]]
** In ''Anime/GreatMazinger'', if he would have not flirted with Jun and followed her when she was buying clothes, the good guys would be dead by the THIRD chapter.
** In the ''Anime/{{Mazinkaiser}}'' movie, he pretty much saved the world (or at least what's left, since at that point is a CrapsackWorld). The Mycene's plan to send one of their general to attack Koji while he is out of Mazinkaiser is completely foiled because Boss attacked the general [[{{Irony}} with Boss Borot]].
* In ''Anime/NeonGenesisEvangelion'', everything is going perfectly for Gendo, until Rei FINALLY gets some self-awareness and realises that no matter how fucked up Shinji is, he would '''still''' be a better choice for godhood than a) the lunatic standing with his hand in her chest (literally) b) the group of lunatics who are killing everyone Rei has ever known. So the world is destroyed, recreated and in the end everyone who wants to live is allowed to live. [[GainaxEnding Or SOMETHING...]]
* In ''Anime/SuperDimensionFortressMacross'', the Zentradi plans to capture the SDF-1 ''Macross'' would have succeeded without a hitch were it not for the unpredictable fighting methods of the defenders, as well as the GlamorousWartimeSinger Lynn Minmay who is ''insanely'' good [[MusicForCourage at rising the heroes's morale.]]
* In ''VisualNovel/HigurashiWhenTheyCry,'' [[spoiler:the only arcs in which the village is safe are Watanagashi and Meakashi because Shion kills Rika in secret, and so the mass gassing can't take place within the time that it would take for the virus to incubate, and by the time they did figure out that Rika was dead, oops, it doesn't look like the villagers are going to kill each other after all]]. This doesn't really make things better for the main characters, though. After all, most of them are still dead. It does, however, clue a mysterious third party in on what's going on; the one aware of the GroundhogDayLoop.
%%* The titular ''Anime/IrresponsibleCaptainTylor'' is either the dictionary definition of this trope or the most brilliant and subtle [[TheChessmaster Chessmaster]] in the entire show, depending on how you look at it.
* ''Anime/CodeGeass'':
** ''The cat'' nearly succeeds at exposing Lelouch and wrecking all his plans simply by accidentally getting its head stuck in his Zero mask and wandering off with it. Before long, the entire boarding school has caught wind that Lelouch is chasing a cat across campus and the situation balloons into a race against time as Milly Ashford, the mischievous president of the [[AbsurdlyPowerfulStudentCouncil student council]], offers a bounty to anyone who can catch the cat and obtain the "embarrassing secret" she assumes it's carrying.
** Ironically, Lelouch could count as ''his own'' Spanner: on multiple occasions, his attachment to his friends (mostly Suzaku or Shirley, but '''''especially''''' his sister Nunnally) have caused him to make moves that jeopardize his plans or even ''the entire rebellion'' he leads. The first occurrence in R1 is where he [[spoiler: lets Villetta live, because he thought she was no danger to him]]. When was that? Second episode. The big ones are where he [[spoiler: ignores his own unstable Geass, leading to the death of Euphemia as he geasses her into becoming a GenocidalManiac and then has to shoot her dead to stop her]], and where he abandoned his followers for his kidnapped sister shortly afterward which ''greatly'' weakened their position, his trait continued on in R2. This came to the logical conclusion [[spoiler:when his RoaringRampageOfRevenge for the murder of Shirley, carried out against a cult whose members included scientists and children, which ended up being a large part of Prince Schneizel's efforts to turn the Black Knights against him - the centerpiece being the fact that their beloved leader possesses a MindControl eye and quite possibly forced them all into obedience (he didn't, probably because he's smart enough not to misuse a power that only works once).]]
** Suzaku Kururugi is both this and an UnwittingPawn. When [[spoiler:Marianne brought him to the Sword of Akasha (possibly thinking he'd side with her out of love for her stepdaughter Euphemia, or because of his friendship with her "vessel" Anya Alstreim)... he sided with ''Lelouch'' instead.]] Not only that, but he messes up Schneizel's plans, as well: [[spoiler: Schneizel was planning to eventually kill off his father and become Emperor, but Suzaku realised this and volunteered to help... right in front of several subordinates who were very worried about doing something like that, including Cornelia (who had never considered such a thing, but went along with the idea anyway)... and Gino Weinberg aka Knight of Three, who's highly loyal to the Emperor. Who escaped with his mecha and told Bismarck Waldstein, the Emperor's personal sword.]] This made Schneizel's attempt to blame it on Lelouch or the Black Knights completely impossible.
** Villetta:
*** Villetta is really one of the biggest ones for Lelouch, as she figures out his identity as Zero early on (not to mention her part in Shirley's [[TraumaCongaLine emotional descent]], becomes part of the Britannian security detail spying over Lelouch due to her knowledge of and arguably immunity to Geass, and is later a key part of the betrayal in R2 19, as she is the convincing factor for Ohgi, and subsequently the rest of the Black Knights, even with a cursory amount of evidence of Geass (with respect to the truth). The latter of which ends up pushing Lelouch towards the [[ThanatosGambit Zero Requiem]]. And why does she become such a problem? [[spoiler: Because Lelouch couldn't bring himself to kill a woman who is unarmed and, at that moment, no threat to him.]] Bad decision, there.
*** The CompilationMovie series essentially tones down her role as this. While she still tries finding evidence about Lelouch, her inolvement with Shirley is changed to having Deithard be the one to shoot her and cause her amnesia in order to retrieve her evidence. Even when Schneizel in this version reveals C.C is the source of Lelouch's Geass, the Black Knights show more reluctance towards betraying him by wanting him to answer their questions first before passing judgement. It's not so much her or Ohgi this time as it is Schneizel and Kanon by having their men be the ones that try to gun down Lelouch before the Black Knights could get their answers.
** One of the biggest would have to be Princess Euphemia. When Brittanian occupiers were murdering Japanese civilians by the dozens and pretty much enslaving those who survived, it was easy for Lelouch's [[LaResistance violent revolution]] to gain followers. But then good natured Euphemia [[RoyalsWhoActuallyDoSomething is put in a position of power]]; [[AllLovingHeroine she]] starts treating the Japanese people with respect, tries to find a compromise solution that both Brittania and Japan can live with, and just like that all of Lelouch's popular support goes bye-bye. Lelouch actually '''admits''' defeat to Euphemia, calling her his most formidable opponent.
* ''Anime/{{Noir}}'':
** Mireille Bouquet may the least deadly of the assassin girls in the series (which only means that she has to obey the laws of physics), but her ability to tell the AncientConspiracy that it can go screw itself and her surprising faith in her partner brings down a major portion of it.
** Most importantly, [[spoiler: Mireille's mother Odette's LastRequest was... for Kirika, ''her own soon to be killer'' and later Mireille's aforementioned partner, to take care of Mireille. A last wish that, many years later, Kirika would ultimately follow to the letter - ruining Altena's desire for a Chloe/Kirika Noir match.]]
* [[spoiler:Midori Sugiura]] from ''Anime/MaiHime'' threw a big wrench in the BigBad's plans to take over/destroy the world through the "winner" of the [[ThereCanBeOnlyOne battle royale]] by enlisting the help of the most unlikely of characters: [[spoiler:Miyu the RobotGirl, whom she located and rebooted. More importantly, she lets her ''keep'' her memories of Alyssa, deciding to trust in that. More than the right decision considering this allowed what seems to be the ''spirit'' of Alyssa to activate Miyu's strongest mode and ''smash the pillars'' containing the souls of those sacrificed, with the side effect of freeing the previous Crystal Princess...]]
* ''Franchise/PrettyCure'':
** TheMovie of ''Anime/YesPrecure5'' has the movie's BigBad, Shadow, steal the device the heroines were using to collect the MacGuffin {{Mon}}s of the series, then uses his mirrors to attract every last one of them into the device. With the girls watching, he ends up using it to wish for world domination. It seems that he's won, but... ''nothing happened''. Why? [[spoiler:Urara completely forgot to add the last of the {{MacGuffin}}s to the device, meaning that it's not complete and therefore doesn't work]]. ''Oops!'' The scary part is that the villain, by all accounts, would have ''won'' if Ms. Cure Spanner hadn't messed everything up.
** Cline's zeal to [[YouHaveOutlivedYourUsefulness get rid of those he deems useless to the cause of Labyrinth]] in ''Anime/FreshPrettyCure'' only failed once, and that's because the Akarun [[spoiler:[[DidntSeeThatComing brought Setsuna Higashi (his first target) back to life]] and]] [[HeelFaceTurn transformed Setsuna into one of the Cures]].
** ''Anime/PrettyCureAllStars''
*** Kage's big plan to defeat the Cures in ''New Stage 2'' is derailed because [[Anime/SmilePrettyCure Miyuki]] invited [[Anime/DokiDokiPrecure Mana and her friends]] to the Fairy Academy - his GreatBigBookOfEverything had ''nothing'' on the Doki-Doki team and thus couldn't exploit their TransformationTrinket weakness.
*** Happens again in ''New Stage 3'' - Nozomi's the one who frees the other Cures from their dream worlds, thanks to the fact that [[PluckyGirl she doesn't like being given things on silver platters.]]
* In ''Manga/ChronoCrusade'' Aion admits [[spoiler:that his plan failed because he didn't take Rosette Christopher into account.]] "No one could predict the actions of such a foolhardy young woman!" Of course, in [[AdaptationDecay the anime adaptation]] the main characters are closer to being {{Unwitting Pawn}}s...
* ''Manga/{{Monster}}''. [[spoiler:The perfect suicide that Johan planned as the end of his GambitRoulette is ruined when an alcoholic townsperson angrily shoots him in the side of the head before Dr. Tenma can kill him.]]

* HotBlooded BadassNormal Sanosuke Sagara from ''Manga/RurouniKenshin'' once threw a wrench in MagnificentBastard Shishio's plans by [[spoiler:sneaking close to his battleship and wrecking it with some bombs given by his friend Katsu, an explosives expert. This prevented Shishio from bombing Kyoto. And [[GracefulLoser Shishio]] [[LampshadeHanging openly acknowledged Sanosuke's role in this]].]]
* ''Anime/{{Rune Soldier|Louie}}'': The idiotic sorcerer Louie ruins the SecretWeapon when he takes a leak in an unusual spot. After that he punches his way through a impenetrable barrier ruining Plan B as well.
* In ''Manga/{{Basilisk}}'', Princess Oboro may not be able to fight, but she derails [[spoiler: BigBad Tenzen]]'s plans ''thrice''. First, [[spoiler: she tries to interrupt a fight between Koushirou and Gennosuke but accidentally causes Koushirou to [[EyeScream blind himself with his own powers]], limiting Tenzen's physical actions since Koushirou is his NumberTwo]]. Second, [[spoiler: she seals her own [[AntiMagic Piercing Eyes]] to avert using her incredibly lethal powers against her clansmen again, but ''also'' preventing Tenzen from using said powers for his sole benefit.]] And third, [[spoiler: her eyes are unsealed when ''Tenzen is reviving himself after Gennosuke kills him'', which allows her to undo Tenzen's {{Immortality}} and kills him for good]]. And in the end she also [[spoiler: derails Ofuku's plans via commiting a HeroicSuicide instead of killing a completely defenseless Gennosuke, sending her into a ''huge'' VillainousBreakdown.]]
* ''Anime/AshitaNoNadja''
** The main protagonist Nadja is this. [[spoiler:When their SmugSnake boss Hermann betrays them, Rosso and Bianco ruin his plans as they let a kidnapped Nadja escape and tell her where to find their reports. Nadja not only gets away and finds the reports, but is the one who manages to give them to the authorities and soon Hermann is thrown in jail for attempted murder ''and'' his own massive debts.]]
** Also, [[spoiler:Hermann]] thought that hiring [[spoiler:Rosemary]] as [[spoiler:Nadja's BodyDouble]] would give him an advantage. WRONG! [[spoiler:Rosemary, despite being just 13 years old, proved to be much smarter and more independent than Herman believed, flat-out telling him that if he tried to discard her, she'd reveal their plans and he'd go down with her.]] Suck on ''that'', SmugSnake.
* ''Manga/{{Naruto}}'':
** BigBad Tobi outright calls Naruto one of these after he defeated Pain and convinced him and Konan to turn against Akatsuki, which led to Tobi losing Pain's resurrection technique, Amegakure's support, and the technique needed to seal the two remaining tailed beasts into the Gedo Mazo.
** Killer Bee also threw a spanner in Akatsuki's plans, when he faked his own capture to ''go on a vacation''. He does it again, when he foils Kisame's attempt to capture him, helped with Kisame's sword betraying him and Killer Bee's brother [[BigDamnHeroes turning up to save him]]. However, it later turns out that Kisame throwing away the fight was all part of the plan.
** Sasuke is one to Itachi's plan, which was ironically meant to keep Sasuke safe. Sasuke's actions lead to the exact opposite of what Itachi had planned for him, culminating in him becoming a criminal wanted by two villages.
** Tobi also becomes a spanner to Itachi's plans, as after Itachi's death, he starts revealing Itachi's secrets to people that he wanted to hide them from.
** Itachi has foiled or complicated the plans of nearly every single person or organization he's come across in the series. In chronological order, the Uchiha clan's plan to revolt against Konoha, Danzo's plan of taking over Konoha, Orochimaru's plan of stealing Itachi's Sharingan eyes and later preventing him from taking over Sasuke's body, Team 7's attempts to rehabilitate Sasuke (in order to preemptively foil any plans Danzo might have after the Third Hokage's death), a failed attempt to foil Akatsuki's plans as TheMole and also a failed attempt to foil Tobi's plan to brainwash Sasuke. Even the ''resurrected'' Itachi foils Kabuto's plans by sealing the resurrected Nagato, and then traps Kabuto himself in an infinite loop. Phew! He also foils ''his own plans'' for Sasuke multiple times by needlessly messing up with an already vengeful Sasuke's mind.
** Kabuto threw a spanner in Tobi's plan summoning [[spoiler:the real Madara Uchiha. He did made Tobi's plan far more complicated as he never intended to resurrect Madara in the first place.]]
** [[spoiler:Ironically, Tobi himself became a spanner in Black Zetsu plans with his reluctance to resurrect Madara and a wish to take control of the Moon’s Eye Plan since Black Zetsu wanted that reincarnation Indra in the person of Madara has completed the plan, that forced him to use Kabuto in order to revive Madara as zombies in first place. Also his HeelFaceTurn and his a wish help team 7 becomes a spanner to Kaguya the plan to get rid of them and ultimately becomes the cause of her defeat and re-sealed.]]
* Three of the 12 Sisters in ''Anime/CoyoteRagtimeShow'', [[DayOfTheWeekName Oct, Nove, and Diesse]], accidentally sent an enemy ship flying into a bomb capable of an EarthShatteringKaboom... [[spoiler:and nothing happens, revealing the bomb above the planet Graceland to be a fake. Spannered further by the militants who act on this information, who are unaware that the fake bomb was a distraction to keep people from finding the real bomb, which is ''already'' on the planet and was moments away from being disarmed before they killed the people negotiating for it.]]
* ''Manga/KatekyoHitmanReborn'' has a mid-level mechanic incidentally named Spanner that performs a HeelFaceTurn along with [[spoiler:Irie]] in an effort to take down the Future Arc's BigBad Byakuran using his technical knowledge of the base and Millefiore. It would have slightly more effective if Byakuran wasn't an ultimate [[TheChessmaster Chessmaster]] and the in-series King of XanatosSpeedChess forcing the epic battles, struggles and hardships just for his own amusement.
* ''Manga/OnePiece'':
** The Straw Hat Pirates in general:
*** Luffy and his crew have a tendency to do this wherever they go. Captain Kuro, Crocodile, Eneru, [=CP9=], Shiki (from ''[[Anime/OnePieceFilmStrongWorld Strong World]]''), and Z (from ''[[Anime/OnePieceFilmZ Film Z]]'') all had very elaborate plans that were a stone's throw away from fruition, but then along came Luffy and crew. All of the above made the mistake of underestimating them, and paid dearly for it.
*** They also (unsurprisingly) stumbled upon the villainous plot for Fishman Island on their way to the New World, and thwarted that one as well. It helped that BigBad Hody Jones, in spite of knowing everything that the Straw Hats had done before their hiatus, dismissed the nine of them as no threat and used EvilGloating to outright provoke them. With exactly ''one'' ally joining the nine Straw Hats to fight, Hody and his army of 100,000 found themselves on the receiving end of what may be the most devastating CurbStompBattle in the series as a result.
** Monkey D. Luffy in particular:
*** [[IdiotHero Luffy]] honestly doesn't care about the [[TheGovernment World Government's]] rule, or for that matter any of the {{Big Bad}}s he faces. He just won't let anyone he cares about get hurt and will go to any lengths to protect his TrueCompanions. Hence his beating three of the [[PsychoForHire Seven Warlords of the Sea]] (and earning the respect or allegiance of the other four, ''and'' allying with yet another who proved to be TheMole after more were added to the roster), the destruction of Enies Lobby, and the assault upon the [[AristocratsAreEvil most powerful jerkasses]] in the world. Soon afterwards we add [[spoiler:the first successful mass-jail break from [[TheAlcatraz Impel Down]] and his assault upon the Marine HQ, just to save his big brother from being executed.]] The surrounding politics and larger conflict don't enter his mind at all.
*** Luffy's proficiencies to this trope have been lampshaded during the Impel Down arc, when the jailers have to deal with two simultaneous riots on top of Blackbeard's invasion, both as a result of Luffy sneaking in.
---->'''Magellan:''' Nothing is going our way! How could one intruder spark so much mayhem?!
** Sanji:
*** Luffy may be the biggest spanner among the Straw Hat Pirates, but Sanji deserves special mention as well; his skills as a tactician often prove to be the linchpin to the Straw Hats' success. Enies Lobby shows his shrewdness in this ''twice''. First, he lures a bunch of Marines and Agents into the back of the train Puffing Tom, then slips past them while they're distracted and ''detaches their cars behind him,'' stranding them and dealing with almost all of the remaining Mooks and one OneManArmy without having to fight them. Then, when the Buster Call arrives at Enies Lobby, he disappears for a while. When he returns, it's revealed he'd been looking for the controls to the Gates of Justice so he can ''close them and throw the Buster Call ships into disarray.''
*** Much earlier, he shows off his skills in the Alabasta saga. First, all the way back in Little Garden, he happens to intercept a call from Mr. 0 and, pretending to be Mr. 3, tricks Baroque Works into thinking Vivi and the Straw Hats are all dead, meaning they don't have to worry about constant pursuit for a while; plus he intercepts an Eternal Pose to Alabasta, meaning the Straw Hats could leave right away rather than wait a year for the Log Pose to reset. Later, in Alabasta itself, all of the other Straw Hats except Chopper have been captured by Crocodile and trapped in a room that will soon be submerged. He uses a bit of trickery to lure Crocodile and his Dragon out of the building and lure them far enough away to give him time to sneak in and set all of them free. He even taunts Crocodile with a note saying "Mr. Prince was here" for when he comes back and discovers that he's been outsmarted.
*** In Skypeia, the first time Eneru shows any real shock was when he discovers Luffy's rubber body is [[NoSell shockproof]]. The ''second'' time, though, was after he KO's Sanji, but his PartingFromConsciousnessWords hint he's still ruined Eneru's day...by sabotaging the ''Ark Maxim''!
*** As of 862, Sanji might have performed his ''biggest'' spanner act ever... [[spoiler: simply by calling his bride Pudding's ThirdEye [[FreakinessShame "beau]][[FreakyIsCool tiful"]]. Up until then, the AxCrazy BitchInSheepsClothing Pudding was fully willing to shoot him dead with a HandCannon... but since she had been bullied all of her life for that same ThirdEye, Sanji's kind phrase shook her to the core and sent her in a sobbing VillainousBreakdown. This meant: she couldn't bring herself to kill him, Sanji managed to perceive and dodge additional threats in their surroundings (like an attack from Pudding's '''very''' badass ColdSniper older brother Katakuri)... and then Luffy (and some clones of his) got the ''perfect'' opening to [[WeddingSmashers begin crashing the wedding]], undo Big Mom's KillEmAll plans regarding Sanji's family, '''and''' put the plan to ''assassinate'' Big Mom herself in movement.]]
** Marineford:
*** In the Assault of Marineford Arc, [[spoiler:Little Oars, Jr.]] caused the Marines strategy for fighting Whitebeard to backfire when his body blocked a piece of a huge siege wall they were trying to activate from rising.
*** Buggy the Clown also qualifies in that same arc. His desire to grandstand and show off to a world audience led him to capture a video Transponder Snail, meaning that the World Government didn't have total control over what information was getting out of Marineford when they started slaughtering the pirates mercilessly with the Pacifistas, or when Blackbeard betrayed the World Government, indelibly humiliating them in the process.
** Punk Hazard:
*** At the beginning of their journey into the New World, the Straw Hats evade Smoker this way. They were originally planning to go to Raijin island, and Smoker knew they were going there because it was the most dangerous of the New World's first three islands, fitting Luffy's adventurous personality and reckless tendencies. However, due to a timely distress call and pure happenstance, they end up going to an island the Log Pose ''didn't even register''. Thus began the Punk Hazard arc, where the crew accidentally stumbled upon ''another'' long term villainous plot and GovernmentConspiracy, that they inevitably wreck. [[HereWeGoAgain Again]]. And this time, they have a live audience to witness it all over the New World.
*** Going to Punk Hazard destroyed many villains' ongoing plans. It not only derails Doflamingo's 10 year rule, but also devastated Big Mom's, Shogun Orochi's as well as Kaido's plans. Big Mom could never have [[spoiler:laid hands on Sanji]] if not for the trip to Dressrosa, which in turn [[spoiler:bolstered Luffy's own reputation as a prospective Emperor]] when Luffy went charging in to the rescue. Orochi and Kaido's enemies were there in Punk Hazard itself. As they rescued Kin'emon and Momonosuke, they also [[spoiler:revitalized Wano's resistance movement against the tyrannical Orochi, and Momo himself is revealed to be the son of Oden, the transcriptor of the ''Roger Pirates'']]. Also they accidentally saved Zou from being destroyed by Jack, only because Kin'emon and Momo stated it as their destination. The red Poneglyph in Zou in turn provided the most important clue to the route to Laugh Tale. It's safe enough to say both Wano's resistance and Luffy's quest would have failed]] [[UnwinnableByMistake completely by accident]] if Luffy didn't decide to step on the most dangerous island to report on the distress call.
*** Smoker's obsession with catching Luffy has made him into a spanner for a quite number of villains as well. The moment where the Straw Hats evaded him upon entry into the New World led to Smoker following them to Punk Hazard. The presence of both him and Tashigi later proved to be pivotal to the Straw Hats and Law taking down Caesar Clown, as it was Smoker who got Law his heart back from [[spoiler:Vergo]], while his own heart was used to trick Caesar into accidentally killing his subordinate Monet, right before she was about to blow up the island to kill everyone except for Caesar, who, being a Gas Logia, would've been the only survivor. [[spoiler:He also proved to be a spanner for the World Government's propaganda practices. He was absolutely disgusted by the MedalOfDishonor situation issued to him and Tashigi at Alabasta, and confessed as much to the newly conscripted Admiral Fujitora, whose goal/dream is to one day end the Warlord system, admitting the only reason he didn't reveal the truth is because he lacked the power and influence to make people believe him. This inspired Fujitora to delay his report after Doflamingo's defeat and expose to the surrounding islands both Dressrosa's current state and their true saviors, the Straw Hat Pirates and Law, preventing his superiors from trying to cover it up]]. And that, [[spoiler: led to [[NothingIsTheSameAnymore the abolishment of the Seven Warlords System]].]]
** Dressrosa:
*** In the Dressrosa arc, Donquixote Doflamingo hatches what looks like the perfect trap to destroy the Straw Hats with. See, this guy isn't your average villain; not only is he an extremely skilled and powerful [[TheChessmaster Chessmaster]] and ManipulativeBastard, he's also smart enough to know that underestimating Luffy's crew would be a fatal mistake. However, outside factor after outside factor helps the Straw Hat Pirates out, rendering it all moot. The Tontattas, whose people were enslaved by the Donquixote Family, provide intel on the location of the Smile Factory and the identity of the power-user maintaining control over the country's LivingToys. A familiar face from the past shows up at the colosseum, and he probably wouldn't have without the tournament Doflamingo created to trap Luffy, to switch places with Luffy, allowing him to attack Doflamingo's castle undetected. But the biggest spanners came from Doffy's own crew: his officer Violet, who maintained a façade of loyalty since the time she was blackmailed into joining, falls for Sanji's chivalry and switches sides. Giolla, on the tail-end of her capturing the ''Thousand Sunny'', lets her guard down long enough for Brook to pull a YouAreAlreadyDead. Bellamy helps Luffy escape the colosseum because Doffy decided to have him killed. And most of all, there's Sugar, the one turning people into toys. Her being knocked unconscious is the only way for the guise over Dressrosa to be lifted, but no one can get near her. Usopp is captured, but instead of turning him into a toy like the others, she feeds him a grape she believed to be poisoned... which was actually hellishly spicy, and the resulting JumpScare / NightmareFace causes her to faint in shock. Consequently, Doflamingo's precious {{Masquerade}} is shattered, the country sees him for the evil person he truly is, and he's forced to take the most drastic measures that he can.
*** There's also the fact that in the resulting battle, five of the eleven remaining [[OneManArmy One-Man Armies]] in his crew are taken down thanks to pirates that came to the colosseum due to the tournament.
*** It turned out that Sugar herself commited quite the mistake regarding her plan... Due to how her powers work, once she makes somone into a member of the LivingToys group, Sugar must manually create a contract with the victims, forcing them to follow every order given at that point, against their will. She did ''not'' do that with her first victim... who turned out to be the son-in-law of the former King, the ''extremely'' badass gladiator Kyros. As a result Kyros, now the toy Thunder Soldier, managed to retain his free will and do what he could to raise his not-turned daughter Rebecca, became the leader of an underground movement of rebels against Doflamingo's rule, and helped out the Straw Hats to overthrow Doflamingo.
** Trafalgar Law:
*** In a non-Straw Hat example, there's Trafalgar Law. The Dressrosa arc, which escalated to involve nearly every major power in the world in some form—-the Seven Warlords of the Sea, the Four Emperors, the Marines, the World Government, and the Revolutionary Army-—wouldn't have even ''happened'' if it weren't for him in the first place. His alliance with Luffy really did "shake the world" as the papers said, as it put the Straw Hats in the path of the Donquixote Family, leading to all of the above, and the gradual destruction of Donquixote Doflamingo's criminal empire. The thing is, Law, much like Luffy in that regard, doesn't care about ''any'' of it. The ultimate purpose of all his actions, including continuing to live to this very day, for the last ''thirteen years'', has been '''to kill Donquixote Doflamingo'''. If the world has to spiral into chaos just so he can kill the man who murdered the most important person in his life, then so be it... though it's revealed in some chapters that he also seems to want the aftershock he knows will follow Doffy's defeat. Luffy grants his wish for the most part: [[BreakTheHaughty Doffy's not dead, but he's clearly ruined]]. So when the government kicks him out of the Warlords and puts him and Luffy on equal footing, he shrugs it all off as if to say, "SoLongSuckers"
*** The aforementioned "most important person" in Law's life, [[spoiler: Doflamingo's younger brother]] Rocinante, aka Corazon, not only allowed Law to become a spanner in Doffy's plans, but ''also'' was a spanner in his own right. By treating Law with sincere kindness [[BecauseYouWereNiceToMe when no one else would]], Corazon reached for him and became his BigBrotherMentor, beating Law's potential EvilMentor Doflamingo to the punch and restoring Law's lost humanity. Later, [[spoiler: when Doflamingo obtained an ''incredibly'' powerful Devil Fruit (the Op-Op Fruit) Corazon [[ForceFeeding forcibly fed it to Law instead]], curing him from his lethal illness ''and'' [[SuperpowerLottery granting him other VERY good skills]].]] True, [[spoiler: Corazon was shot dead by Doflamingo for that (and for being TheMole for the Marines)]], but ultimately he had a spectacular last laugh since, as said above, Law ultimately became Doflamingo's biggest nemesis.
** Lola from Thriller Bark; During Thriller Bark, she supplies Luffy with the shadows that allow him to pummel the giant zombie Oars, and though that doesn't destroy Oars, it does weaken him enough for the Straw Hats to finish him off. Then, before they part, she gives Nami a Vivre Card that apparently belongs to her mother; [[spoiler: In Totland, it's shown that ''Big Mom'' is Lola's mother, and that card is full of Big Mom's SoulPower, allowing Nami to control the {{Animate Inanimate Object}}s also created by Big Mom. In fact, by leaving Big Mom's territory, ''Lola disrupted an ArrangedMarriage that would have allowed Big Mom to become Pirate Queen!'']]
** In a larger scale, there's a woman named Sora. She foiled the plans of [[spoiler: her husband Judge]] to [[spoiler: experiment with their quadruplet sons, ''that she was still pregnant with'']], by taking a dangerous drug that [[spoiler: undid gene modifications]]. While [[spoiler: only one of the boys was spared being modified]] ''and'' [[spoiler: [[IllGirl her health was damaged beyond repair]], which later [[MissingMom killed her]]]], it turns out [[spoiler: the son that she ''did'' manage to save eventually escaped from his BigScrewedUpFamily and grew into... none other than Vinsmoke ''Sanji'', one of Luffy's TrueCompanions, who's been helping Luffy become a bonafide example of this trope.]]
** The DarkestHour in the Wano arc comes when Shogun Orochi manages to head off the heroes' attempts to covertly build up a rebellion and raid Kaido's island base, Onigashima, by sinking all the ships they had planned to use to travel by water and the bridges they would have used to go by land the night before they were all set to gather. This happened due to the actions of a traitor in the good guys' midst passing along every scrap of information they could, including a last minute change of plans orchestrated by an ally just before his execution. What results is the Ninja-Pirate-Mink-Samurai Alliance arriving at their planned rendezvous, finding no one there, and the traitor revealing themselves in order to [[spoiler:abduct Momonosuke]]. However, it's then revealed that [[spoiler:the message that brought the main allies to this place meant something completely different. The meeting place was different than indicated and, because of the differences in distance between where they were and where everyone else was, everyone else was already in position long before the ships and bridges were demolished]]. Kin'emon, the leader of the samurai, is praised for such a brilliant piece of tactical misdirection, which exposed the traitor, prevented their actions from derailing their plans, and guaranteed the raid on Onigashima could proceed. The thing is, [[spoiler:the only reason the allies were in the wrong place was because Kin'emon misinterpreted the message that changed their plans while everyone else ''didn't''. Upon realizing this, Kin'emon can only stand there stone-faced as he realizes basically "Oh, ''that's'' what that meant..."]]
* ''Anime/DennouCoil'' protagonist Yasako is revealed to be this in the final episode. [[spoiler:When Yasako was about seven years old, she stumbled into a hidden Space being used to help a girl her age, later known as Isako, cope with the death of her older brother. Yasako encounters a simulation of this brother and her affection towards him sparks Isako's insecurities and fears of losing him, resulting in the creation of Miss Michiko, which is the cause for many problems throughout the series]].
* Akiyama sees Nao Kanzaki as this in regards to the ''Manga/LiarGame.'' The Liar Game's producers break even by collecting on the players' debts, and profits when the winning contestants forfeit half of their winnings to OptOut of the game. Nao, however, has consistently been using her winnings to pay off other players' debts while increasing her own as a result. Akiyama believes that Nao has the potential to '''completely bankrupt the Liar Game''' by doing this since by the end, her personal debt will have gotten so high actually ''collecting'' would be impossible.
* Although the events of ''Manga/CardcaptorSakura, Manga/TsubasaReservoirChronicle'', and ''Manga/XxxHoLic'' are among the most complex and [[GambitPileup densely gambited]] known to man, ''none'' of the respective [[TheChessmaster chessmasters]] of the former two expected Yukito to fall in love with Touya instead of Sakura. The gambit ruling the latter one ''did'' anticipate the YaoiGuys - but apparently failed to anticipate a ''heterosexual crush'' from one of them.
* ''Manga/{{Saki}}'':
** Senoo Kaori does this to Mako in the same way as the poker and billiards examples listed in Real Life. Mako's playstyle is based entirely on having watched experienced players all her life. Kaori is a complete beginner. The result is that because Kaori has no idea what she's actually doing, Mako found it impossible to read her discards and ended up losing to her.
** Also, Nodoka [[AgentScully doesn't believe in superstition]], and therefore doesn't notice when something weird is up. In her match against Eisui's Hatsumi, she [[spoiler: derails the plans of Teams Himematsu and Miyamori players, who did notice Hatsumi's ability and were trying to stop it from triggering, by just playing normally]].
* The military high command in ''Anime/StrikeWitches'' were running a conspiracy to [[spoiler:abolish the Strike Witches in favor of their own methods]]. Their plan was all in place and ready to go until Yoshika [[spoiler:attempted peaceful contact with a Neuroi]]. Since the high command's [[spoiler:methods involved illegal use of Neuroi technology]], Yoshika's actions forced them to act prematurely and [[RevealingCoverup made the other Witches realize they were hiding something.]]
* ''LightNovel/FullMetalPanic'': Though not a [[TheDitz ditz]] or stupid like some of the other examples, kidnapping OrdinaryHighSchoolStudent Kaname means that you've instantly lost, because [[IndyPloy she tends to figure out ways to screw up your best laid plans]]. Not to mention the whole "bodyguard with HumongousMecha" thing she has going, and how said bodyguard is the most hardcore BadassNormal the world has ever seen and such.
* ''Manga/FullmetalAlchemist''
** It turns out '''[[spoiler:Scar's older brother]]''' was the first to figure out Father's AncientConspiracy (more exactly: [[spoiler: he was the first person to notice the transmutation circle around the country and began piecing together what's going on; the raid on his country confirmed his suspicions, and he quickly devised countermeasures for it).]] And he did this '''before the series even starts'''! [[spoiler: He may have died to save his younger brother before he could execute the plan but he played a major role in defeating Father, by allowing the heroes to fight back.]] And even more: [[spoiler: by transmuting his own arm to a mutilated Scar ''plus'' imbibing it with the right kind of alchemy, he not only saved his younger brother's life (at the high price of further damaging his mind and soul), but helped him become the one who ultimately took down Fuhrer Bradley aka Wrath, one of the most dangerous Homunculus.]]
** One can't help but pity Father. Despite being an EldritchAbomination who spent centuries erecting a [[GambitRoulette massive plan]] to gain godhood, fate sent an entire legion of fools to ruin his day. In addition to [[spoiler:Scar's brother]], there's Ling Yao and his entourage, who can sense Homunculi and just want the secret of immortality; May Chang, who uses alkahestry instead of alchemy (therefore she lacks its weaknesses) and is on the same quest as her half-brother Ling; and even Scar himself, whose thirst for revenge almost derails the plan several times.
** [[spoiler:The Second Greed]] to Father, who certainly wasn't expecting him to [[spoiler:regain his old memories and betray him a second time]]. Not only does [[spoiler:Greed betray Father]] but he also [[spoiler:joins the heroes to fight against him]]. [[spoiler:Greed]] managed to weaken Wrath (greatly helping Scar) and helped the Briggs soldiers hold the Central fort. He was also crucial in the final battle as he managed to [[spoiler:absorb some of Father's souls and distracted him long enough for the heroes to make him use up his Philosopher's Stone shield]]. Most importantly, after [[spoiler:being [[TheAssimilator absorbed]] by Father (who at this point, still couldn't die due to his regeneration abilities), Greed '''greatly''' [[AssimilationBackfire damages him]] by using his carbonization powers to turn Father's shell into [[MadeOfPlasticine charcoal]], thereby rendering Father unable to regenerate. All that was needed left to destroy Father afterwards was a single punch from Edward]].
* In the Battle of Fairy Tail arc of ''[[Manga/FairyTail Fairy Tail]]'', Erza's false eye is this. Its existence halves the effect of any ocular magic used on her. When Erza is petrified by Evergreen using an ocular attack, the eye allows her to break free and defeat Evergreen.

* ''Manga/MahouSenseiNegima'':
** Nodoka, Kazumi and ''especially'' Chisame derail [[spoiler: Kurt Godel's ThanatosGambit]], because [[spoiler: when Negi goes OneWingedAngel on him after he reveals what happened to his DoomedHometown, Nodoka and Kazumi hold him in place, and then Chisame slaps him back to sanity.]]
** And it's not the only one. [[spoiler: Natsumi Murakami is the owner of an artifact which hasn't been found/used/invoked in ''centuries'', obtained from her Pactio with Koutarou. Said artifact is basically an InvisibilityCloak... and she uses it to bring ''a whole rescue team'' to the place where [[ApocalypseMaiden a captive and unconscious]] [[AntiMagic Asuna]] is about to be used by Fate to rewrite the whole Magical World. Fate's [[OhCrap horrified]] face when he sees what happened is ''priceless''.]]
* In ''LightNovel/{{Durarara}}'', one of the main reasons [[ManipulativeBastard Izaya]] hates Shizuo so much is because his emotional volatility, TooDumbToFool nature, and firmly sustained belief that Izaya is responsible for 99.9% of everything that goes wrong in Ikebukuro makes him liable to become one at any moment -- because all of it makes him immune to Izaya's manipulations. [[spoiler:Shizuo ends up doing exactly this in volume 6, when Izaya's attempt to frame Shizuo and get him out of the way for the moment doesn't go quite as planned and instead brings even ''worse'' people down on Izaya's head]].
* In ''LightNovel/{{Baccano}}'''s Flying Pussyfoot arc, it seems like everyone is this for everyone else, in a plot that was already capable of being summed up in one word: "clusterfuck." [[spoiler:Long story short: the [[{{Cult}} Lemures]] plan to hold the train passengers hostage in return for Huey Laforet's release from prison. [[AxCrazy Ladd Russo]] and his [[TheMafia buddies]] plan to kill a bunch of people ForTheEvulz. Czeslaw Meyer plans to smuggle explosives into New York and sell them. Jacuzzi Splot and his gang of delinquents plan to steal Czeslaw's explosives and sell them. [[OutlawCouple Isaac and Miria]] have already pulled off a robbery and plan to use the train to make their getaway into New York City. [[InformationBroker Daily Days]] agent [[BadassBystander Rachel]] just wants to [[RailEnthusiast hitch a ride]]. And [[SociopathicHero Rail Tracer]] ''does not approve of all these shenanigans going down on his train''.]] All of these plans disrupt one another in spectacular fashion and end in varying levels of success based - with one or two notable exceptions - on how sympathetic the characters involved are.
* ''Franchise/{{Pokemon}}'':
** In ''Manga/PokemonAdventures'', Giovanni has a GameBreaker Deoxys that can Forme Change instantaneously at will. Yes, he's pretty much unstoppable...until Bill and his buddies figure out how it works and disable it.
** ''Anime/{{Pokemon}}'':
*** Bewear of the ''Sun and Moon'' series usually evacuates Team Rocket just as they're about to get their ass kicked, though on some occasions it cuts in just as they're about to defeat the twerps. In some instances they become savvy to this, and one time even leave a distraction for Bewear so they have time to finish a more elaborate scheme.
*** Nebby's Teleport-happy antics also ended up jogging Lillie from her TraumaInducedAmnesia and exposing Faba's scheming that he'd covered up for years.
*** During the finale of ''Anime/PokemonZoroarkMasterOfIllusions'', [[spoiler: Kodai wins, he gets the Time Ripple. All plant-life in Crown City begins to die! But suddenly it turns out to be all an illusion by Zoroark. But [[ThisCannotBe her illusions shouldn't work on him]], he's got a device for that! Well remember that cute little Zorua he's been [[KickTheDog kicking around the whole movie]]? The one who tried his hardest to stop him but failed? Well turns out a lucky little bite in their last scuffle, unknown to ether of them, broke Kodai's illusion canceler, bringing Kodai's plan crashing down.]]
%%*** Ash often manages to throw spanners into his rival's tactics due to his tendency to make seemingly dumb choices of Pokemon (bad type match-ups, significantly smaller Pokemon, etc.) and then do the unexpected with them. Regularly Ash and his team have a habit of obliviously getting in the middle of bad guy's plans just at the most inconvenient of times and pulling them apart.
%%*** The Team Rocket trio of Jessie, James and Meowth almost always manage to create problems for Cassidy and Butch, other Rocket agents, or other villain teams by trying to steal their prize. As several characters have noted, they are actually much better at fighting other villains than fighting the heroes.
* In ''LightNovel/ACertainMagicalIndex'', Touma often derails the complex plans of any character by simply showing up and kicking the crap out of every bad guy in sight. Subverted in that Laura Stewart and Aleister Crowley are {{Magnificent Bastard}}s and can factor him into their schemes. Later, Aleister has a VillainousBreakdown when [[spoiler: Shiage defeats Meltdowner]], raging that it's impossible and ordering his death in an effort to stop him from derailing his calculations any further.
* In the Makai Arc of ''Manga/YuYuHakusho'', Yusuke's decision to hold a tournament was a last ditch effort to eliminate Yomi and Mukuro, since Yusuke knew he had no hope of taking either of them in a fight. However, due to Kurama and co.'s lucky presence, and Mukuro's bugging of Yomi's estate, Yusuke's idea prevents all hell from breaking loose: if Yomi were to simply attempt to kill Yusuke, Kurama, as well as his own elite fighters, would side with Yusuke. While Yomi would be capable of killing them all, he'd expend at least a third of his power doing so, leaving him vulnerable to Mukuro and Hiei, all of this forcing Yomi to accept Yusuke's proposal.

* ''Anime/TigerAndBunny'':
** [[spoiler:Maverick's]] longtime manipulation of [[spoiler:both [=HeroTV=] and Barnaby]] for his own ends is utterly destroyed by a cascading series of spanners in the works, beginning with Kotetsu, who completely inadvertently foils [[spoiler:Maverick]]'s attempt at [[spoiler:wiping potentially incriminating knowledge from his memory]] and forces him into a much grander plan to try and remove him from the picture.
** The plan to try and remove Kotetsu from the picture falls apart thanks to [[spoiler:Kotetsu's former boss, Ben Jackson. Maverick wipes the memories of Wild Tiger's secret identity from the [=HeroTV=] crew, but overlooks Ben, leaving him able to come to Kotetsu's rescue when the other heroes are out to arrest him]].
** And, to a lesser extent than the above, [[spoiler:Judge Yuri Petrov of the Justice Bureau, aka Lunatic. Maverick could not possibly have anticipated that Yuri had done extensive research into Wild Tiger and Wild Tiger's civilian identity after crossing his path as Lunatic, or that Lunatic's obsessive sense of justice would lead him to come to Kotetsu's aid just in the nick of time to keep Kotetsu from being arrested by the fake Wild Tiger]].
** And finally, [[spoiler:Kotetsu's daughter Kaede, who goes into Sternbild to help prove her father's innocence. When she approaches Maverick to ask for help, he has no idea who she is or that she's recently manifested the power to duplicate the powers of any NEXT she touches, and simply pats her on the head... unwittingly giving her the ability to undo his brainwashing of the other heroes with a well-timed EmotionBomb. Even once he's realized who she is and taken her hostage, he and Rotwang ''still'' fail to properly account for her power, and thanks to coming into contact with Blue Rose shortly before their capture she's able to prevent Rotwang from executing the heroes in his deathtrap.]]
* ''Anime/MawaruPenguindrum'':
** [[spoiler: Ringo Oginome]] pretty much tells [[spoiler: Shoma Takakura]] that he became one for her [[spoiler: "Project M"]] in episode 11. This, because [[spoiler: Shoma is the first person to question said "Project M", in which Ringo wants to reach almost all the possible extremes to bear the child of Tabuki-sensei since it means [[MySiblingWillLivethroughMe she'll live the life of her dead older sister]] Momoka; among other things, Shouma tells Ringo that she's herself and ''not'' Momoka, which later makes her think twice in regards to having sex with a {{Love Potion}}ed!Tabuki.]]
** There's another one whose spanning "powers" act on a bigger scale: [[spoiler: Masako Natsume]].[[spoiler: In her backstory episode, we find out that she doesn't want to be used by Sanetoshi at all and only goes along with his plans resentfully to keep her little brother Mario alive. Later on, she refuses to burn her half of the Destiny Diary, which serves as some sort of seal on Sanetoshi's power; the entire diary does get burnt to bits by episode 23, but Masako's refusal holds him off long enough for Ringo to learn the Fate Transfer spell.]]

* In ''Anime/PrincessTutu'' '''Ahiru''' is this to Drosselmeyer. Made more ironic by the fact ''he'' was the one to bring her into the story to get it moving. It did... in the direction ''[[EarnYourHappyEnding opposite]]'' to what he wanted.
* In ''Manga/AnatoliaStory'', Queen Nakia needs a special girl's blood to perform a powerful BloodMagic that will kill her stepson Kail and give her the chance to make her own son Juda the heir to the Hitite Empire. Too bad that the girl she brought into Hattusa as her prospect HumanSacrifice, Yuri Suzuki, turned out to be a naive but very fast-learning PluckyGirl who decided to fight back to protect herself, then became the partner and concubine of the same prince Nakia wanted to murder, and she not only ended up becoming Nakia's strongest rival but also one of the most influential people in the nation.
* Eren [[spoiler:being a titan shifter]] in ''Manga/AttackOnTitan'' derailed [[spoiler:the other titan shifters]]'s plans by causing them to shift their focus towards Eren.
* ''Manga/RosarioToVampire'': In his first appearance, Gin tried to set Tsukune up to take the fall for Gin's own perversions in an effort to have Moka all to himself. The only reason it failed is because Kurumu was about to comfort Tsukune just as Gin intercepted him. Kurumu followed them and stumbled across [[{{Frameup}} a certain episode behind the school involving a digital camera and the girls' locker room]]. Afterwards, she rescued Tsukune from the vengeful locker room girls, confronted Gin on the roof, and presented a testimony that confirmed Moka's already-growing doubts about Tsukune's role in the incident.
* ''Anime/FutureGPXCyberFormula'': [[CorruptCorporateExecutive Smith]] and [[PunchClockVillain Bootsvorz]]'s plans to steal [[SuperPrototype Asurada GSX]] get folded multiple times of time due to unexpected mishaps:
** Smith sending a helicopter to shoot down the truck delivering GSX to Team Sugo gets sabotaged by a 14-year-old boy on a motorcycle who gets unhurt and capable or driving the car to safety.
** A sabotage on Hayato before the Niseko GP gets ruined when Ohtomo Johji, a veteran friendly driver, happens to be out to practice that night as well.
** On the Niseko GP, Bootsvorz's first attempt to crash out the car gets ruined by Hayato's sudden pit entry for a set of rain tire. An unexpected rainfall that follows causes him - running on slick - to spin out.
** His second attempt also gets ruined because a random car gets out of a mud trap and blocks the gap between to two machines. The heavy rain causes him and the said car to crash each other out.
** In the Brazilian GP, Bootsvorz gets into a perfect spot to take down GSX, but he doesn't expect a rival driver Knight Shoemach to [[HeroicSacrifice deliberately crash him out at the last second]] to protect it.
** Smith's personal attempt at taking out both Shoemach and Bootsvorz gets spoiled when Hayato, driving GSX into a shortcut, jumps out of nowhere and scares him, indirectly leading him to his death.
* In the second part of the ''Anime/ExplorerWomanRay'' [=OVA=]s, Ray [[spoiler: uses a crystal pendant on the Ord temple - which uses controlled light beams as a means of somehow controlling the weather - in order to stop bad guy Rieg Vader from controlling it.]]
* The first cour of ''Anime/{{Endride}}'' revolved around a) Prince Emilio wanting to [[{{Patricide}} kill King Delzaine]], b) his friends trying to dissuade him because they need answers from Delzaine, c) the [[LaResistance Ignauts]] trying to get Delzaine to peacefully step down while fighting off his [[QuirkyMinibossSquad enforcers]], the [[LesCollaborateurs Truculent]], and d) Shun trying to get to Babylon so he can use the Babel device to return to his world. Come the mid-season climax, [[spoiler:instead one of the Truculent, [[AxeCrazy Ibelda]], slaughters all his teammates, kills Delzaine himself, and jumps into the Babel device, meaning absolutely no one got what they wanted, and a whole new set of problems were created besides.]]

* In ''Manga/SaintSeiya'' and its non-canon SpinOff ''Anime/SaintSeiyaSoulOfGold'', Pisces Aphrodite was on both ends of the trope:
** In the first, Aphrodite had devised a pretty good back-up plan shall he lose his fight with Shun: he anticipated the Saints would try and have someone keeping him busy while the other continued to run, so he planted his poisonous roses on the stairs behind his temple to act as DeadlyGas. By all rights, he had won with mocking ease, ''and'' it was about to work since Seiya fell for it in his despair and urge to go forward... [[spoiler: But then, Seiya's mentor Marin showed up. As a Female Saint, Marin had to wear a CoolMask - so she put it on Seiya, which allowed him to recover from the poison even when it poisoned ''her'' instead. As he wasn't breathing poison anymore ''and'' he saw his beloved mentor collapsed, Seiya gained enough physical strength and HeroicWillpower to destroy the roses, clearing his path to the top and towards the BigBad.]] [[spoiler: And by the way, Shun defeated and killed Aphrodite anyway.]]
** In the second, Aphrodite apparently lost his ''first'' fight against [[spoiler: Andreas Rize]] after being revived [[spoiler: and was absorbed into the mighty Yggdrassil tree]]... but in reality, he had become this and was waiting for the exact moment to show it. [[spoiler: When [[DemonicPossession Loki-in-Andreas'-body]] got his hands on Gungnir and destroyed the Odin Robe, the tide was turned a the fallen Gold Saints returned, all because Aphrodite [[AcquiredPoisonImmunity was immune to plant toxins]] ''[[AcquiredPoisonImmunity -even Yggdrasil's-]]'' and was able to develop countermeasures, so the also absorbed and "killed" Gold Saints were only kept in a deathlike state but did ''not'' actually die. Aphrodite even pointed out Loki's '''fatal''' mistake to his face.]]
* The Future Gadget Lab in ''VisualNovel/SteinsGate'', a literal basement (apartment) amateur lab in a cheap building is this to the world back and forth. Completely by accident they discover Time Travel which gives the [[HiddenVillain Committee of 300]] SERN division the ability to conquer the world, becoming a Spanner to the world. As they perfect the Time Travel method they become one to themselves by painting a giant target on their backs, in order to fix this they have to reverse what they have done essentially becoming a spanner for SERN and the Committee, and the best thing is, due to the timeline override SERN is non the wiser.

* In ''Anime/SakuraWarsTheMovie'', the Rose Division's involvement in helping the Flower Division [[spoiler:take back their theater and destroying the Japhkiel incubation facilities]], as well as Ogami's return from Paris, ultimately put a dent in [[spoiler:Douglas-Stewart's plans for making the Flower Division obsolete]].

* ''Manga/DeathNote'' has a few:

** Shidou performs this twice, though he's a fairly stupid shinigami.

*** That wasn't the worst thing he did. The worst thing he did was wrecking Light and Misa's alibi by revealing the fake Death Note rules. Had that not happened, even if Near suspected Light he would have no base for his suspicion, and Light would not have handed over Misa's Death Note to Mikami. And in true DidntSeeThatComing fashion, Light didn't even learn about Shidou's existence until the damage was already done. Any other instance on this page either would not have happened or could not have damaged Light's plans if Shidou hadn't done that. It wasn't as though that would have saved Light. After all L was already going to test and see if the fake rules were legit and Near would've done the same. The only thing that occurred because of him is that they didn't have to perform the test.

** Mello in the anime certainly counts as a non-stupid example. The purpose of adding him to the show was to add someone straightforward and somewhat reckless to wreck the other main characters' quiet, roundabout and complicated plans. There ''is'' a simple, unexpected genius in just driving up in a motorcycle, tossing smoke grenades into the crowd and ''grabbing'' your target instead of laying an elaborate trap, now isn't there?
*** Mello was sort of a reverse Spanner, or perhaps [[{{Metaphorgotten}} a spanner used properly instead of being thrown into the works]], in that his actions did not ''screw up'' Light's plans directly but rather led Near to ''perfect'' his plans.
*** Without Mello being the spanner in someone's works, [[GambitPileup Near and Light would have continued planning and counter-planning with no end in sight.]] That's why Near said that him and Mello together were better than L; Near could make the plans and Mello could prevent any countering of those plans. This is especially important, when you realize that L was all but certain Light was guilty 99.9% of the time. He just couldn't get past that .01%...
* Mugen from ''Anime/SamuraiChamploo'' is a prime example. In the first episode, Mugen dispatches a horde of mooks and then approaches their boss, who then explains to Mugen how he is the son of the town's corrupt governor. Any attempts to harm the son of an important official will be a death sentence. He then confidently asks Mugen if he got all that. Mugen responds with, "Not a word," and then attacks him.

* Similarly, [[InspectorOblivious Mihoshi]] from ''Anime/TenchiMuyo'' actually has a distinguished service record with the Galaxy Police, but the backstory indicates it's largely a result of her bumbling in and causing too much chaos for any dastardly plan to hold up.
** In the original {{O|riginalVideoAnimation}}VA it was suggested she actually had had a mental breakdown from being overworked which turned her from a top cop into a comic ditz -- as hinted by Kagato's comment about her past exploits. (And he should know, since Mihoshi's meddling [[spoiler: led to the release of Washu, whom [[CrystalPrison he held hostage]] ''in a PocketDimension inside Kagato's CoolSpaceship that no one but Washu and Kagato knew of'', and yet Mihoshi somehow got there with ease.]]) Later versions, though, lack this detail and instead are all just lucky enough to be teamed up with Kiyone, who usually can get the job done in spite of Mihoshi. Yet as evidenced by her enormous reports, Mihoshi still seems ridiculously thorough.

** In the first Tenchi movie, ''Tenchi Muyo In Love'', Washu's plan to capture KAIN and prevent him from killing Achika gets derailed when KAIN decides [[TakingYouWithMe if he goes, he's taking Achika with him.]] It gets worse when Noboyuki is dragged along, too.

* The titular ''Anime/IrresponsibleCaptainTylor'' is either the dictionary definition of this trope or the most brilliant and subtle [[TheChessmaster Chessmaster]] in the entire show, depending on how you look at it.
* ''The cat'' in ''Anime/CodeGeass'' nearly succeeds at exposing Lelouch and wrecking all his plans simply by accidentally getting its head stuck in his Zero mask and wandering off with it. Before long, the entire boarding school has caught wind that Lelouch is chasing a cat across campus and the situation balloons into a race against time as Milly Ashford, the mischievous president of the [[AbsurdlyPowerfulStudentCouncil student council]], offers a bounty to anyone who can catch the cat and obtain the "embarrassing secret" she assumes it's carrying.

** Villetta is really one of the biggest ones for Lelouch, as she figures out his identity as Zero early on (not to mention her part in Shirley's [[TraumaCongaLine emotional descent]], becomes part of the Britannian security detail spying over Lelouch due to her knowledge of and arguably immunity to Geass, and is later a key part of the betrayal in R2 19, as she is the convincing factor for Ohgi, and subsequently the rest of the Black Knights, even with a cursory amount of evidence of Geass (with respect to the truth). The latter of which ends up pushing Lelouch towards the [[ThanatosGambit Zero Requiem]].
*** And why does she become such a problem? [[spoiler: Because Lelouch couldn't bring himself to kill a woman who is unarmed and, at that moment, no threat to him.]] Bad decision, there.

* TheMovie of ''Anime/YesPrecure5'' has the movie's BigBad, Shadow, steal the device the heroines were using to collect the MacGuffin {{Mon}}s of the series, then uses his mirrors to attract every last one of them into the device. With the girls watching, he ends up using it to wish for world domination. It seems that he's won, but... ''nothing happened''. Why? [[spoiler:Urara completely forgot to add the last of the {{MacGuffin}}s to the device, meaning that it's not complete and therefore doesn't work]]. ''Oops!'' The scary part is that the villain, by all accounts, would have ''won'' if Ms. Cure Spanner hadn't messed everything up.

** Kage's big plan to defeat the Cures in ''Anime/PrettyCureAllStars New Stage 2'' is derailed because [[Anime/SmilePrettyCure Miyuki]] invited [[Anime/DokiDokiPrecure Mana and her friends]] to the Fairy Academy - his GreatBigBookOfEverything had ''nothing'' on the Doki-Doki team and thus couldn't exploit their TransformationTrinket weakness.

* ''Anime/AshitaNoNadja'' has the main protagonist as this. [[spoiler:When their SmugSnake boss Hermann betrays them, Rosso and Bianco ruin his plans as they let a kidnapped Nadja escape and tell her where to find their reports. Nadja not only gets away and finds the reports, but is the one who manages to give them to the authorities and soon Hermann is thrown in jail for attempted murder ''and'' his own massive debts.]]

* In ''Manga/{{Naruto}}'', BigBad Tobi outright calls Naruto one of these after he defeated Pain and convinced him and Konan to turn against Akatsuki, which led to Tobi losing Pain's resurrection technique, Amegakure's support, and the technique needed to seal the two remaining tailed beasts into the Gedo Mazo.

*** Tobi also becomes a spanner to Itachi's plans, as after Itachi's death, he starts revealing Itachi's secrets to people that he wanted to hide them from.
** Itachi has foiled or complicated the plans of nearly every single person or organization he's come across in the series. In chronological order, the Uchiha clan's plan to revolt against Konoha, Danzo's plan of taking over Konoha, Orochimaru's plan of stealing Itachi's Sharingan eyes and later preventing him from taking over Sasuke's body, Team 7's attempts to rehabilitate Sasuke (in order to preemptively foil any plans Danzo might have after the Third Hokage's death), a failed attempt to foil Akatsuki's plans as TheMole and also a failed attempt to foil Tobi's plan to brainwash Sasuke. Even the ''resurrected'' Itachi foils Kabuto's plans by sealing the resurrected Nagato, and then traps Kabuto himself in an infinite loop. Phew! He also foils ''his own plans'' for Sasuke multiple times by needlessly messing up with an already vengeful Sasuke's mind.

** [[IdiotHero Luffy]] honestly doesn't care about the [[TheGovernment World Government's]] rule, or for that matter any of the {{Big Bad}}s he faces. He just won't let anyone he cares about get hurt and will go to any lengths to protect his TrueCompanions. Hence his beating three of the [[PsychoForHire Seven Warlords of the Sea]] (and earning the respect or allegiance of the other four, ''and'' allying with yet another who proved to be TheMole after more were added to the roster), the destruction of Enies Lobby, and the assault upon the [[AristocratsAreEvil most powerful jerkasses]] in the world. Soon afterwards we add [[spoiler:the first successful mass-jail break from [[TheAlcatraz Impel Down]] and his assault upon the Marine HQ, just to save his big brother from being executed.]] The surrounding politics and larger conflict don't enter his mind at all.
** As a matter of fact, Luffy and his crew have a tendency to do this wherever they go. Captain Kuro, Crocodile, Enel, [=CP9=], Shiki (from ''[[Anime/OnePieceFilmStrongWorld Strong World]]''), and Z (from ''[[Anime/OnePieceFilmZ Film Z]]'') all had very elaborate plans that were a stone's throw away from fruition, but then along came Luffy and crew. All of the above made the mistake of underestimating them, and paid dearly for it.
*** They also (unsurprisingly) stumbled upon the villainous plot for Fishman Island on their way to the New World, and thwarted that one as well. It helped that BigBad Hordy Jones, in spite of knowing everything that the Straw Hats had done before their hiatus, dismissed the nine of them as no threat and used EvilGloating to outright provoke them. With exactly ''one'' ally joining the nine Straw Hats to fight, Hordy and his army of 100,000 found themselves on the receiving end of what may be the most devastating CurbStompBattle in the series as a result.
** At the beginning of their journey into the New World, the Straw Hats evade Smoker this way. They were originally planning to go to Raijin island, and Smoker knew they were going there because it was the most dangerous of the New World's first three islands, fitting Luffy's adventurous personality and reckless tendencies. However, due to a timely distress call and pure happenstance, they end up going to an island the Log Pose ''didn't even register''. Thus began the Punk Hazard arc, where the crew accidentally stumbled upon ''another'' long term villainous plot and GovernmentConspiracy, that they inevitably wreck. [[HereWeGoAgain Again]]. And this time, they have a live audience to witness it all over the New World.
*** Believe it or not, going to Punk Hazard destroyed many villains' ongoing plans. Not only it derails Doflamingo's 10 year rule (see below), but also [[spoiler: devastated Big Mom's, Orochi's as well as Kaido's plans. Big Mom could never have laid hands on Sanji if not for the trip to Dressrosa, which in turn bolstered Luffy's own reputation as a prospective Emperor, and Orochi and Kaido's enemies were there in Punk Hazard itself. As they rescued Kinemon and Momonosuke, they also revitalized Wano's resistance movement against the tyrannical Orochi, and Momo himself is revealed to be the son of Oden, the transcriptor of the ''Roger Pirates''. Also they accidentally saved Zou from being destroyed by Jack, only because Kinemon and Momo stated it as their destination. The red Poneglyph in Zou in turn provided the most important clue to the route to Raftel. It's safe enough to say both Wano's resistance and Luffy's quest would have failed]] [[UnwinnableByMistake completely by accident]] if Luffy didn't decide to step on the most dangerous island to report on the distress call.
** Luffy's proficiencies to this trope have been lampshaded during the Impel Down arc, when the jailers have to deal with two simultaneous riots on top of Blackbeard's invasion, both as a result of Luffy sneaking in.
--->'''Magellan:''' Nothing is going our way! How could one intruder spark so much mayhem?!
** Luffy may be the biggest spanner among the Straw Hat Pirates, but Sanji deserves special mention as well; his skills as a tactician often prove to be the linchpin to the Straw Hats' success. Enies Lobby shows his shrewdness in this ''twice''. First, he lures a bunch of Marines and Agents into the back of the train Puffing Tom, then slips past them while they're distracted and ''detaches their cars behind him,'' stranding them and dealing with almost all of the remaining Mooks and one OneManArmy without having to fight them. Then, when the Buster Call arrives at Enies Lobby, he disappears for a while. When he returns, it's revealed he'd been looking for the controls to the Gates of Justice so he can ''close them and throw the Buster Call ships into disarray.''

** In the Assault of Marineford Arc, [[spoiler:Little Oars, Jr.]] caused the Marines strategy for fighting Whitebeard to backfire when his body blocked a piece of a huge siege wall they were trying to activate from rising.
** Buggy also qualifies in that same arc. His desire to grandstand and show off to a world audience led him to capture a video Den Den Mushi (Transponder Snail), meaning that the World Government didn't have total control over what information was getting out of Marineford when they started slaughtering the pirates mercilessly with the Pacifistas, or when Blackbeard betrayed the World Government, indelibly humiliating them in the process.
** In the Dressrosa Arc, Donquixote Doflamingo hatches what looks like the perfect trap to destroy the Straw Hats with. See, this guy isn't your average villain; not only is he an extremely skilled and powerful [[TheChessmaster Chessmaster]] and ManipulativeBastard, he's also smart enough to know that underestimating Luffy's crew would be a fatal mistake. However, outside factor after outside factor helps the Straw Hat Pirates out, rendering it all moot. The Tontattas, whose people were enslaved by the Donquixote Family, provide intel on the location of the Smile Factory and the identity of the power-user maintaining control over the country's LivingToys. A familiar face from the past shows up at the colosseum (and he probably wouldn't have shown up without the tournament Doflamingo created to trap Luffy) to switch places with Luffy, allowing him to attack Doflamingo's castle undetected. But the biggest spanners came from Doffy's own crew: his officer Violet, who maintained a façade of loyalty since the time she was blackmailed into joining, falls for Sanji's chivalry and switches sides. Giolla, on the tail-end of her capturing the ''Thousand Sunny'', lets her guard down long enough for Brook to pull a YouAreAlreadyDead. Bellamy helps Luffy escape the colosseum because Doffy decided to have him killed. And most of all, there's Sugar, the one turning people into toys. Her being knocked unconscious is the only way for the guise over Dressrosa to be lifted, but no one can get near her. Usopp is captured, but instead of turning him into a toy like the others, she feeds him a grape she believed to be poisoned… which was actually hellishly spicy, and the resulting JumpScare / NightmareFace causes her to faint in shock. Consequently, Doflamingo's precious {{Masquerade}} is shattered, the country sees him for the evil person he truly is, and he's forced to take the most drastic measures that he can.

** In a non-Straw Hat example, there's Trafalgar Law. The Dressrosa arc, which escalated to involve nearly every major power in the world in some form—-the Seven Warlords of the Sea, the Four Emperors, the Marines, the World Government, and the Revolutionary Army-—wouldn't have even ''happened'' if it weren't for him in the first place. His alliance with Luffy really did "shake the world" as the papers said, as it put the Straw Hats in the path of the Donquixote Family, leading to all of the above, and the gradual destruction of Donquixote Doflamingo's criminal empire. The thing is, Law, much like Luffy in that regard, doesn't care about ''any'' of it. The ultimate purpose of all his actions, including continuing to live to this very day, for the last ''thirteen years'', has been '''to kill Donquixote Doflamingo'''. If the world has to spiral into chaos just so he can kill the man who murdered the most important person in his life, then so be it... though it's revealed in some chapters that he also seems to want the aftershock he knows will follow Doffy's defeat. Luffy grants his wish for the most part: [[BreakTheHaughty Doffy's not dead, but he's clearly ruined]]. So when the government kicks him out of the Warlords and puts him and Luffy on equal footing, he shrugs it all off as if to say, "SoLongSuckers"
*** The aforementioned "most important person" in Law's life, [[spoiler: Doflamingo's younger brother]] Rocinante aka Corazon, not only allowed Law to become a spanner in Doffy's plans, but ''also'' was a spanner in his own right. By treating Law with sincere kindness [[BecauseYouWereNiceToMe when no one else would]], Corazon reached for him and became his BigBrotherMentor, beating Law's potential EvilMentor Doflamingo to the punch and restoring Law's lost humanity. And later, [[spoiler: when Doflamingo obtained an ''incredibly'' powerful Devil Fruit (the Ope Ope no Mi) Corazon [[ForceFeeding forcibly fed it to Law instead]], curing him from his lethal illness ''and'' [[SuperpowerLottery granting him other VERY good skills]].]] True, [[spoiler: Corazon was shot dead by Doflamingo for that (and for being TheMole for the Marines)]], but ultimately he had a spectacular last laugh since, as said above, Law ultimately became Doflamingo's biggest nemesis.
** Lola from Thriller Bark; During Thriller Bark, she supplies Luffy with the shadows that allow him to pummel the giant zombie Oars, and though that doesn't destroy Oars, it does weaken him enough for the Straw Hats to finish off. Then, before they part, she gives Nami a Vivre Card that apparently belongs to her mother; [[spoiler: In Totland, it's shown that ''Big Mom'' is Lola's mother, and that card is full of Big Mom's SoulPower, allowing Nami to control the {{Animate Inanimate Object}}s also created by Big Mom. In fact, by leaving Big Mom's territory, ''Lola disrupted an ArrangedMarriage that would have allowed Big Mom to become Pirate Queen!'']]
** In a larger scale, there's a woman named [[spoiler: Vinsmoke]] Sora. She foiled [[spoiler: her husband Judge]]'s plans of [[spoiler: experimenting with their quadruplet sons ''that she was still pregnant with'']] by taking a dangerous drug that [[spoiler: undid gene modifications]]. While [[spoiler: only one of the boys was spared of being modified]] ''and'' [[spoiler: [[IllGirl her health was damaged beyond repair]] (which later [[MissingMom killed her]]]]), it turns out [[spoiler: the son that she ''did'' manage to save eventually escaped from his BigScrewedUpFamily and grew into... none other than '''Vinsmoke Sanji''', one of Luffy's TrueCompanions, who's been helping Luffy become a bonafide example of this trope.]]
** As of 862, Sanji might have performed his ''biggest'' spanner act ever... [[spoiler: simply by calling his bride Pudding's ThirdEye [[FreakinessShame "beau]][[FreakyIsCool tiful"]]. Up until then, the AxCrazy BitchInSheepsClothing Pudding was fully willing to shoot him dead with a HandCannon... but since she had been bullied all of her life for that same ThirdEye, Sanji's kind phrase shook her to the core and sent her in a sobbing VillainousBreakdown. This meant: she couldn't bring herself to kill him, Sanji managed to perceive and dodge additional threats in their surroundings (like an attack from Pudding's '''very''' badass ColdSniper older brother Katakuri)... and then Luffy (and some clones of his) got the ''perfect'' opening to [[WeddingSmashers begin crashing the wedding]], undo Big Mom's KillEmAll plans regarding Sanji's family, '''and''' put the plan to ''assassinate'' Big Mom herself in movement.]]
** Smoker's obsession with catching Luffy has made him into a spanner for a quite number of villains as well. The above moment where the Straw Hats evaded him upon entry into the New World led to Smoker following them to Punk Hazard. The presence of both him and Tashigi later proved to be pivotal to the Straw Hats and Law taking down Caesar Clown, as it was Smoker who got Law his heart back from [[spoiler:Vergo]], while his own heart was used to trick Caesar into accidentally killing his subordinate Monet, right before she was about to blow up the island to kill everyone (except for Caesar, who, being a Gas Logia, would've been the only survivor). [[spoiler:He also proved to be a spanner for the World Government's propaganda practices. He was absolutely disgusted by the MedalOfDishonor situation issued to him and Tashigi at Alabasta, and confessed as much to the newly conscripted Admiral Fujitora, whose goal/dream is to one day end the Warlord system, admitting the only reason he didn't reveal the truth is because he lacked the power and influence to make people believe him. This inspired Fujitora to delay his report after Doflamingo's defeat and expose to the surrounding islands both Dressrosa's current state and their true saviors, the Straw Hat Pirates and Law, preventing his superiors from trying to cover it up]]. And that, [[spoiler: led to [[NothingIsTheSameAnymore the abolishment of the Seven Warlords System]].]]
** The DarkestHour in the Wano arc comes when Shogun Orochi manages to head off the heroes' attempts to covertly build up a rebellion and raid Kaido's island base, Onigashima, by sinking all the ships they had planned to use to travel by water and the bridges they would have used to go by land the night before they were all set to gather. This happened due to the actions of a traitor in the good guys' midst passing along every scrap of information they could, including a last minute change of plans orchestrated by an ally just before his execution. What results is the Ninja-Pirate-Mink-Samurai Alliance arriving at their planned rendezvous, finding no one there, and the traitor revealing themselves in order to [[spoiler:abduct Momonosuke]]. However, it's then revealed that [[spoiler:the message that brought the main allies to this place meant something completely different. The meeting place was different than indicated and, because of the differences in distance between where they were and where everyone else was, everyone else was already in position long before the ships and bridges were demolished]]. Kin'emon, the leader of the samurai, is praised for such a brilliant piece of tactical misdirection, which exposed the traitor, prevented their actions from derailing their plans, and guaranteed the raid on Onigashima could proceed. The thing is, [[spoiler:the only reason the allies were in the wrong place was because Kin'emon misinterpreted the message that changed their plans while everyone else ''didn't''. Upon realizing this, Kin'emon can only stand there stone-faced as he realizes basically "Oh, ''that's'' what that meant]]...

* Senoo Kaori in ''Manga/{{Saki}}'' does this to Mako in the same way as the poker and billiards examples listed in Real Life. Mako's playstyle is based entirely on having watched experienced players all her life. Kaori is a complete beginner. The result is that because Kaori has no idea what she's actually doing, Mako found it impossible to read her discards and ended up losing to her.

* ''Manga/DragonBall'':
** The [[ArmiesAreEvil Red Ribbon Army]] is a worldwide military organisation planning to use the [[MacGuffin Dragon Balls]] to TakeOverTheWorld. Too bad they didn't expect to be dealing with a [[KidHero 12-year-old boy]] [[SimpleStaff with a stick]] after the [[OrphansPlotTrinket Four Star Dragon Ball]] left to him by his deceased grandfather. In fact, Goku may not have been inclined to attack the Red Ribbon Army's headquarters... until they sent the hitman Tao Pai Pai to kill the guy who ''happened'' to have the ball Goku wanted. This meant Goku had to make amends to the guy's son, and that meant he now had to get ''all'' the balls to revive the dude... including the ones the Red Ribbons had already collected. ''[[OhCrap Their base is now a target.]]''
** An earlier example would be at the end of the first Dragon Ball hunt. Pilaf has summoned the Dragon and is about to wish for world domination, but he never expects one of the good guys to escape from their prison and change the wish...like Oolong did.
-->'''Pilaf:''' I wish to rule-
-->'''Oolong:''' The panties off a hot babe!
** And afterwards, preparing to kill the heroes for their interference, Pilaf's palace is destroyed by Goku, having turned into a giant monkey monster.
** In ''Anime/DragonBallZ'', Gohan and Krillin become this to both Vegeta and Frieza on Namek. First, Gohan steals the Dragon Ball that Vegeta took and hid. Second, Gohan and Krillin teaming up with Vegeta against the Ginyu Force kept them alive long enough for Goku to arrive and save them, taking out the last major force on Frieza's side. Then, their friendship with the Namekians gave them access to the Dragon Balls, allowing them to wish Piccolo back to life, bring him to Namek, and deny Frieza and Vegeta their chance at immortality.
** Vegeta ends up being a spanner at the climax of the Cell Games arc. While Gohan is in a beam struggle with Cell, all of the other fighters seem helpless to even budge Cell, and it seems that Cell is set to kill Gohan. But, Vegeta hits Cell with a blast from behind that's just strong enough to make Cell briefly lose his footing, distracting him. This allows Gohan to unleash all of his remaining power, destroying Cell down to the atomic level, finally getting rid of him.
** King Yenma and Fortuneteller Baba are this in the Buu arc. Had they not brought back Vegeta to fight Super Buu, Goku wouldn't have anyone to [[FusionDance fuse with]], and would have remained completely outclassed by Super Buu.

** In ''Anime/DragonBallSuper'', Manga/JacoTheGalacticPatrolman ends up being this towards Champa's team in the Champa arc. Vegeta had suspected something wrong when, during Goku's match with Frost, the Saiyan is taken down so easily. However, during Frost's match with Piccolo, Jaco spots Frost slipping his right arm inside Piccolo's stretched and wrapped arm. When Frost defeats a now-poisoned Piccolo and declared winner, Jaco objects and tells the announcer to check his right arm. [[spoiler:Frost had a needle implanted inside his right forearm coated with poison. Frost is disqualified ''and'' disgraced while Piccolo becomes the real winner.]] Even more, Jaco risked being ''obliterated on the spot'' for a possible lie to expose this.
** Later on in ''Super'', Cell does this posthumously. In the beginning of the Future Trunks arc, Goku Black destroys Trunks' time machine, rendering the heroes unable to return to the Future Trunks timeline... but what Black ''didn't'' know was that Cell had ''also'' time-travelled to the present (since his Future Trunks had already destroyed the Androids and prevented him from achieving his perfect form) and left ''his'' version of the time machine behind. The heroes found it, and Bulma kept it, providing them with a backup to follow him with.
* ''Manga/MahouSenseiNegima'' has [[spoiler: Nodoka, Kazumi and ''specially'' Chisame]] derailing [[spoiler: Kurt Godel's ThanatosGambit]], because [[spoiler: when Negi goes OneWingedAngel on him after he reveals what happened to his DoomedHometown, Nodoka and Kazumi hold him in place, and then Chisame slaps him back to sanity.]]

* ''Anime/{{Pokemon}}'': Ash often manages to throw spanners into his rival's tactics due to his tendency to make seemingly dumb choices of Pokemon (bad type match-ups, significantly smaller Pokemon, etc.) and then do the unexpected with them.
** Regularly Ash and his team have a habit of obliviously getting in the middle of bad guy's plans just at the most inconvenient of times and pulling them apart.
** Also the Team Rocket trio. Jessie, James and Meowth almost always manage to create problems for Cassidy and Butch, other Rocket agents, or other villain teams by trying to steal their prize. As several characters have noted, they are actually much better at fighting other villains than fighting the heroes.
** Bewear of the ''Sun and Moon'' series usually evacuates Team Rocket just as they're about to get their ass kicked, though on some occasions it cuts in just as they're about to defeat the twerps. In some instances they become savvy to this, and one time even leave a distraction for Bewear so they have time to finish a more elaborate scheme.
** Nebby's Teleport-happy antics also ended up jogging Lillie from her TraumaInducedAmnesia and exposing Faba's scheming that he'd covered up for years.
* In ''Manga/PokemonAdventures'', Giovanni has a GameBreaker Deoxys that can Forme Change instantaneously at will. Yes, he's pretty much unstoppable...until Bill and his buddies figure out how it works and disable it.
* During the finale of ''Anime/PokemonZoroarkMasterOfIllusions'', [[spoiler: Kodai wins, he gets the Time Ripple. All plant-life in Crown City begins to die! But suddenly it turns out to be all an illusion by Zoroark. But [[ThisCannotBe her illusions shouldn't work on him]], he's got a device for that! Well remember that cute little Zorua he's been [[KickTheDog kicking around the whole movie]]? The one who tried his hardest to stop him but failed? Well turns out a lucky little bite in their last scuffle, unknown to ether of them, broke Kodai's illusion canceler, bringing Kodai's plan crashing down.]]

* In ''Anime/TigerAndBunny'', [[spoiler:Maverick's]] longtime manipulation of [[spoiler:both [=HeroTV=] and Barnaby]] for his own ends is utterly destroyed by a cascading series of spanners in the works, beginning with Kotetsu, who completely inadvertently foils [[spoiler:Maverick]]'s attempt at [[spoiler:wiping potentially incriminating knowledge from his memory]] and forces him into a much grander plan to try and remove him from the picture...
** ...which falls apart thanks to [[spoiler:Kotetsu's former boss, Ben Jackson. Maverick wipes the memories of Wild Tiger's secret identity from the [=HeroTV=] crew, but overlooks Ben, leaving him able to come to Kotetsu's rescue when the other heroes are out to arrest him]].
** And, to a lesser extent than the above, [[spoiler:Judge Yuri Petrov of the Justice Bureau, aka Lunatic. Maverick could not possibly have anticipated that Yuri had done extensive research into Wild Tiger and Wild Tiger's civilian identity after crossing his path as Lunatic, or that Lunatic's obsessive sense of justice would lead him to come to Kotetsu's aid just in the nick of time to keep Kotetsu from being arrested by the fake Wild Tiger]].

* [[spoiler: Ringo Oginome]] pretty much tells [[spoiler: Shoma Takakura]] that he became one for her [[spoiler: "Project M"]] in episode 11 of ''Anime/MawaruPenguindrum''. This, because [[spoiler: Shoma is the first person to question said "Project M", in which Ringo wants to reach almost all the possible extremes to bear the child of Tabuki-sensei since it means [[MySiblingWillLivethroughMe she'll live the life of her dead older sister]] Momoka; among other things, Shouma tells Ringo that she's herself and ''not'' Momoka, which later makes her think twice in regards to having sex with a {{Love Potion}}ed!Tabuki.]]

* Nine times out of ten, bad guys in ''Franchise/{{Gundam}}'' tend to get their plans uprooted because of this.

** In ''Anime/GundamBuildFighters'', Chairman Mashita of PPSE creates arcade game-like machines that [[MundaneUtility animate Gundam model kits]], which have become a worldwide phenomenon and made him a nice chunk of change. And then along comes Reiji, the prince of the otherworldly kingdom from which Mashita stole the [[MinovskyPhysics unusual particles]] which make Gunpla Battle machines work. Afraid that Reiji's victory would give him the spotlight and the opportunity to expose Mashita's theft, the Chairman begins rigging the World Tournament in the hopes of eliminating Reiji...but due to his piloting skills, the model-building talents of his partner Sei Iori, and the TrueCompanions bonds they share with each other and most of the tournament's other participants, every attempt thusfar has failed. Ultimately, he threw in his Trump Card, a BrainwashedAndCrazy Meijin Kawaguchi III and his Exia Dark Matter, causing the duo to defeat him and also expose the truth of those particles.

* In ''Manga/HonooNoAlpenRose'', [[spoiler: Jeudi]] and, in the anime, [[spoiler: her mother Helene]] were this. The first, via [[spoiler: appearing in the Durant mansion and thus throwing a wrench in the local SmugSnake Toulonchamp's plans, which involved him having his own daughter Mathilda as his spy as well as Jeudi's BodyDouble to twist the Durants's arms into helping him]]; it goes double when [[spoiler: she reveals her knowledge of the ''Alpine Rose'' song when she's being taken away (by singing it in the anime and or leaving a handwritten version of the lyrics in the anime), letting Helene know the truth and identify ''her'' as her daughter instead of Mathilda.]] The second, via [[spoiler: crawling towards Toulonchamp in the middle of a HostageSituation and holding on his leg while he's about to kidnap Jeudi at knife point, distracting him enough to let Jeudi's boyfriend Lundi pounce on him ''and'' setting Jeudi free.]]

* In ''Anime/SakuraWarsTheMovie'', the Rose Division's involvement in helping the Flower Division [[spoiler:take back their theater and destroying the Japhkiel incubation facilities]], as well as Ogami's return from Paris, ultimately put a dent in [[spoiler:Douglas-Stewart's plans for making the Flower Division obsolete]].
----

* In ''Manga/FullmetalAlchemist'', it turns out '''[[spoiler:Scar's older brother]]''' was the first to figure out Father's AncientConspiracy (more exactly: [[spoiler: he was the first person to notice the transmutation circle around the country and began piecing together what's going on; the raid on his country confirmed his suspicions, and he quickly devised countermeasures for it).]] And he did this '''before the series even starts'''! [[spoiler: He may have died to save his younger brother before he could execute the plan but he played a major role in defeating Father, by allowing the heroes to fight back.]] And even more: [[spoiler: by transmuting his own arm to a mutilated Scar ''plus'' imbibing it with the right kind of alchemy, he not only saved his younger brother's life (at the high price of further damaging his mind and soul), but helped him become the one who ultimately took down Fuhrer Bradley aka Wrath, one of the most dangerous Homunculus.]]

** Smoker's obsession with catching Luffy has made him into a spanner for a quite number of villains as well. The above moment where the Straw Hats evaded him upon entry into the New World led to Smoker following them to Punk Hazard. The presence of both him and Tashigi later proved to be pivotal to the Straw Hats and Law taking down Caesar Clown, as it was Smoker who got Law his heart back from [[spoiler:Vergo]], while his own heart was used to trick Caesar into accidentally killing his subordinate Monet, right before she was about to blow up the island to kill everyone (except for Caesar, who, being a Gas Logia, would've been the only survivor). [[spoiler:He also proved to be a spanner for the World Government's propaganda practices. He was absolutely disgusted by the MedalOfDishonor situation issued to him and Tashigi at Alabasta, and confessed as much to the newly conscripted Admiral Fujitora, whose goal/dream is to one day end the Warlord system, admitting the only reason he didn't reveal the truth is because he lacked the power and influence to make people believe him. This inspired Fujitora to delay his report after Doflamingo's defeat and expose to the surrounding islands both Dressrosa's current state and their true saviors, the Straw Hat Pirates and Law, preventing his superiors from trying to cover it up]].

* In ''ANime/SakuraWarsTheMovie'', the Rose Division's involvement in helping the Flower Division [[spoiler:take back their theater and destroying the Japhkiel incubation facilities]], as well as Ogami's return from Paris, ultimately put a dent in [[spoiler:Douglas-Stewart's plans for making the Flower Division obsolete]].

*** Without Mello being the spanner in someone's works, [[GambitPileup Near and Light would have continued planning and counter-planning with no end in sight.]] That's why Near said that him and Mello together were better than L; Near could make the plans and Mello could prevent any countering of those plans.

** Teru Mikami screwed up by going for his notebook when Kiyomi Takada was kidnapped by Mello, which lead Near to the notebook ... If it hadn't been for this one mistake, which allowed Near to successfully replace the notebook with a fake, Light would have won. Unusually for a Spanner, this wasn't a result of stupidity but of Mikami thinking ''too much'' like Light: he did exactly what Light would've done in his situation, with the limited information available. In the manga, Light even acknowledges this.