History SpannerInTheWorks / VideoGames

* ''VideoGame/GrimGrimoire'' has the TheArchmage preparing to break free from his SoulJar and take the philosopher's stone and menace the world, and powerful devil he entered a pact with named Grimlet is about ready to break from being sealed inside the old wizard Gammel Dore. Neither of them could possibly predict that both of their plans would screwed up by one CuteWitch named Lillet Blann caught in GroundhogDayLoop.

* ''VideoGame/FinalFantasyIV'' has the Dark Elf mess up Golbez's plans to steal the Earth Crystal from Troia by snatching it first and running off to a cave where he rendered metal weapons unusable. The Dark Elf did this basically because the crystal was shiny. Golbez [[XanatosSpeedChess works around this]] by sending protagonist Cecil to [[MacGuffinDeliveryService fetch the crystal]] in exchange for [[DamselInDistress Rosa]].

** This is actually a {{reconstruct|edTrope}}ion. [[spoiler:Makoto's Spanner status comes from the fact that she never knew Noel never existed in this timeline up until Terumi's plans had already fallen apart. Other than that, she had proven through the entire story that she was capable of picking up on the world around her and using the intel she accumulated to formulate and rebuild her plans on a whim - one slip of the tongue by Terumi was enough for her to, with help from Bang's keen-eyed disciple, figure out that Relius was luring her into a trap and adjusted her plans just enough to defuse the problem and keep at work. Had she known about that missing fact any time before she ran into Tsubaki, she could have {{outgambitted}} Terumi instead.]]

* In ''VideoGame/GrandiaII'', this role goes to Millenia. The BigBad's plan requires [[spoiler:that all eight pieces of Valmar be absorbed by Millenia so that Valmar's resurrection can be brought about and the BigBad can merge with him.]] What the villain didn't count on was [[spoiler:Millenia refusing to absorb the Horns after they merged with Ryudo, and then sealing them inside Ryudo rather than risk killing him. As a result, not only was Valmar's resurrection incomplete, but Ryudo eventually used the Horns as a weapon to kill the villain.]]
* In ''VideoGame/TheWorldEndsWithYou'', Neku points out to a ManipulativeBastard that it is utterly impossible to predict what [[IdiotHero Beat]] is going to do. Heck, if you collect the Secret Report after the end of the game, even [[spoiler:the Angel, Mr. Hanekoma, thought Neku was screwed before Beat's HeelFaceTurn, which was conveniently possible because of his FaceHeelTurn in the first place.]]
* ''Franchise/{{Persona}}'':
** ''VideoGame/Persona3'': After his [[TheReveal reveal]] as TheChessmaster, [[spoiler:Shuji Ikutsuki]] plans to sacrifice most of the party by [[spoiler:forcing RobotGirl Aigis to murder them]] in order to bring about TheEndOfTheWorldAsWeKnowIt. He's just about to succeed... but at that point, the player is reminded that he forgot to crucify the dog, too.
** ''VideoGame/Persona5'': [[spoiler:Akechi]] ends up being the fatal flaw in [[spoiler:Shido]]'s chain of operations once the team recalls he overheard a specific part of a conversation that he shouldn't have been able to hear. Which was [[spoiler:Morgana's ability to be heard by humans after being in the Metaverse]], allowing the team to outmaneuver his plans and trick him into revealing the name of his employer. [[spoiler: Ironically, his real goal was to bring down Shido himself from within, [[TheOnlyOneAllowedToDefeatYou and felt the team was getting in his way.]]]]
* ''VideoGame/WhiteKnightChronicles'': You are this for [[spoiler: GreaterScopeVillain]] Emperor Madoras. Or, rather, your custom character is. (The game features an incredibly robust character creation system, and it's an unwritten rule amongst the fandom that the avatar be based off of the player.) After sitting back silently during the story mode while (most likely, should you choose to play the game's plethora of side quests that require your avatar) being the most devastating character in combat, you are the only one able to take on Madoras in the game's bonus dungeon.
* ''VideoGame/WorldOfWarcraft'':
** Every raid dreads the LeeroyJenkins, who can ruin an otherwise carefully arranged plan of attack by charging in headfirst.
** In ''Wrath of the Lich King'', after Drakuru plays you for an UnwittingPawn, you get to do this to his plans repeatedly, all while he thinks he's recruiting you.
** Calia Menethil becomes this in the ''Before The Storm'' novel. Its central plot revolves around King Anduin Wrynn setting up a reunion of undead Forsaken and their human loved ones, separated by the fall of Lordaeron. Calia is the last living member of Lordaeron's royal family, and her being recognized is a concern because it might bring up more problems than it solves now that Lordaeron is the kingdom of the undead. Despite this, she makes a case to be allowed to attend the gathering itself and help with the reunions. However, one of the Forsaken there [[spoiler:recognizes her, and that recognition starts a chain of events that leads to the deaths of every Forsaken in attendance and Calia herself, all at the hands of the Forsaken leader Sylvanas Windrunner, who immediately assumes that Calia, once she's revealed, is there as a usurper, and isn't entirely wrong either]].
* ''VideoGame/{{Xenosaga}}'': [[spoiler:The entire plan of the BigBad, that has taken centuries and all three games to complete, is undone because Allen can take a beating and look really pathetic while it happens]].
* A much more minor, but hilarious, example comes from ''VideoGame/ChronoTrigger''. Ozzie, inept sidekick to the great Magus, was originally defeated by being dropped down a TrapDoor. In his second coming, he's smart enough to make the switches instead drop the ''heroes'' down the trap door. When they come back, Ozzie's ready for anything... except for a not-so-random ''cat'' (if you get the regular ending, Chrono's cat(s) jump into the time portal), which wanders in, flips the wrong switch, and down he goes...
* In ''VideoGame/SoulNomadAndTheWorldEaters'', Lujei Piche apparently is stated to have ruined the effort involved [[spoiler:in banishing Sulfur of ''VideoGame/PhantomBrave'', sending him back to Ivoire as a BonusBoss.]]
** Revya and Gig, for all the multiple times they are {{Unwitting Pawn}}s during the storyline, also become epic spanners: [[spoiler:The demon path is basically you laying waste to the entire GambitPileup: Virtious, Thuris, Dio, Rashka and all the other manipulators' year-long plans are ruined by one free-roaming OmnicidalManiac doing it ForTheEvulz.]]
* In VideoGame/Disgaea2, the entire reason Overlord Zenon's plan fails to rule over Holt is partially because of Adell, partially because of Adell's mother, and partially because of many other members of the case. None, however, do the damage that Axel does, who wants to be famous as the "Dark Hero" again, so he sends out Overlord Zenon's home address across every news outlet he can, and Zenon's castle is quickly overrun with Overlords. By the time you get to him, he's practically exhausted from fighting constantly all day with god-tier opponents.
* In ''VideoGame/FateExtella'', Elizabeth Bathory plays this role. She is [[spoiler:corrupted]] by the BigBad to further his plans. Unfortunately for him, not only does she have no desire to follow his orders, but she is also not the brightest mind around. In Tamamo's storyline, [[spoiler:she was supposed to take all pieces of the Regalia and then destroy it. Instead, for some inexplicable reason she eats her own piece, baffling everyone who witnesses her action.]] In the final story arc, [[spoiler:the BigBad has the heroes cornered and all his bases covered. Elizabeth then decides to release the previously sealed Titan Altera to consume her powers. However, she only realizes that she doesn't have any idea of how to do that after she releases the seal. The newly freed Titan Altera promptly defeats her and arrives just in time to save the day.]] When the BigBad realizes that it was her stupidity that ruined his plans, it sends him into a VillainousBreakdown.
* ''VideoGame/FinalFantasyIV'' has the Dark Elf mess up Golbez's plans to steal the Earth Crystal from Troia by snatching it first and running off to a cave where he rendered metal weapons unusable. The Dark Elf did this basically because the crystal was shiny. Golbez [[XanatosSpeedChess works around this]] by sending protagonist Cecil to [[MacGuffinDeliveryService fetch the crystal]] in exchange for [[DamselInDistress Rosa]].
* ''Franchise/FinalFantasy'':
** Vaan from ''VideoGame/FinalFantasyXII'' is the only one besides Ashe to [[spoiler:see a loved one's image projected by the Occuria, in this case, his brother Reks. This implies that he would be a suitable and effective 'Plan B' to become the weapon which would destroy the Archadian Empire in revenge should Ashe falter]]. Probably due to his being both Dalmascan, and for, at the start of the game, harbouring resentment towards Archadia for the death of his brother. Instead, Vaan actually overcomes [[spoiler:the illusions much more quickly than Ashe]], ultimately providing a more virtuous role model, as seen when he refuses to take revenge on Gabranth for killing his brother. [[FridgeBrilliance He may just have been the push Ashe needed to reject revenge at the story's climax]].
** It's not so easy to see because he's a minor villain, but the [[VideoGame/FinalFantasyI Dark Elf King Astos]] has been at his plot for years, then the Warriors of Light come out of nowhere, on a completely unrelated quest, and straight up murder him. And while it might seem like Astos spanned his own plot, his theory was that the artifacts he tricked the Warriors of Light into getting him would make him all-powerful, so revealing himself isn't stupid so much as GenreBlindness.
** ''[[VideoGame/DissidiaFinalFantasy Dissidia 012]]'' retcons it that just one Warrior of Light, who is a [[spoiler: Manikin]]. This guy is such a spanner that he manages to bring down plots in two worlds without even knowing his own name, let alone his ridiculously complicated origin story.
** In ''VideoGame/FinalFantasyXIV'', it's Yotsuyu's burning hatred for her own countrymen that leads to Doma and Ala Mhigo's liberation. She had ruled Doma with a cruel and vicious fist, stomping down on her people in retaliation for the wrongs in her life. That meant that no one was willing to even lift a finger against their captors until the Scions arrive. When Zenos showed up in Doma, only Yugiri and the Warrior of Light were willing to challenge him, but their actions end up spurring up the rebellion Zenos hoped to crush during his visit.
* [[HeroicWannabe Ash DragonBlade's]] story in ''VideoGame/DragonFable'' from Creator/ArtixEntertainment consists of Ash foiling the plots of would be [[BigBad Big Bads]] through his own sheer stupidity.
* In ''[[VideoGame/LaPucelle La Pucelle Tactics]]'' the plans of both Noir and [[spoiler:the spirit infecting Croix]] are foiled not by the Maiden of Light, but by Priere, a newbie priestess who is perhaps the least likely person you'd expect being a nun, though she has a mean right hook and an even meaner set of legs.
* In ''VideoGame/FinalFantasyCrystalChroniclesEchoesOfTime'', [[spoiler:Larkeicus [[HoistByHisOwnPetard does this to ''his own'' plan]]. He builds a tower to reach the point in the sky where the hero's going to cause the crystals 2000 years ago to vanish, and [[CrazyPrepared prepares for every possible outcome]], [[XanatosGambit including his own defeat]]. Too bad he forgot to consider how the hero would get that high up in the first place.]]
* In ''VideoGame/EvilGenius'', this can easily happen to the player if (s)he gets careless. Even the lowest of the agents of justice can become this if you neglect to pay attention.

* ''VideoGame/{{Miitopia}}'': Among the residents of Greenhorne, the only ones whom the Dark Lord doesn't steal a face from are the Worried Mother, the Lovey Dovey Man and the Dubious Mayor. This allows the first of these to give you the charm which unleashes a guardian spirit, who gives you the power to fight the monsters and save Miitopia from evil.
* [[spoiler:General Shepherd]] didn't expect one thing in ''[[VideoGame/ModernWarfare Modern Warfare 2]]''. [[spoiler:SAS Captain John Price. Price firing the nuke at Washington caused Shepherd to resort to some XanatosSpeedChess and move up his timetable for TF 141's disposal, but Price's willingness to [[EnemyMine co-operate with Makarov]] pushed him on to the defensive and gave him a [[EyeScream knife through the eye]].]]

* The Alien protagonist in ''VideoGame/AliensVsPredator2''.
* ''VideoGame/MegaManZX''
** The cornerstone of Master Albert's plan to [[AGodAmI become a god]] involved gathering the world's Model Ws and combine them into Ouroboros. However, aside from shitting out Mavericks like an ominous ring of land, it has no way to prevent an airship from crashing into it and inserting a war party intent on shutting him down. If he had a few more Model Ws, he could have sprung for mounted anti-air... too bad the Guardians (and Mega Man Model ZX) got to them first (and subsequently destroyed them). The thing to note is that this is a Spanner entry because Albert's plan would have been more complete had they not been destroyed; everything else went [[MemeticMutation just as planned]].
** Another example is how a pair of excavators accidentally awaken Grey, [[spoiler:Master Albert's back-up body]]. After witnessing what Model W can do, Grey ends up saying no to Master Albert's plan and becomes instrumental in his downfall. Ashe also counts since in her storyline, she encounters Model A by accident and singlehandedly ruins Albert's plan as well. Albert even notes that her appearing was entirely unpredicted, and the amount of trouble she caused for him surprised most people directly involved.

* ''VideoGame/TeamFortress2'':
** While [[MagnificentBastard the Spy's]] entire ''job'' is to be the Spanner in the enemy team's works, random chance tends to play this role in otherwise evenly matched teams, as nobody can account for that stray lucky critical hit (some players consider this to be such a ScrappyMechanic that they play on servers where random crits are turned off).
** And then there are the {{Griefer}}s, who ''purposely sabotage their own team's objectives'' ForTheEvulz.
** The Engineer can also cause some major setbacks to an enemy team, be it placing Dispensers to support a teammate who would be killed by attrition, Teleporting allies to bypass enemy lines, or through a well-placed Sentry to block off an otherwise viable path.
*** [[ComicallyMissingThePoint Except he has a wrench, not a spanner]].
* The protagonists of ''Franchise/SilentHill'' tend to be played for {{Unwitting Pawn}}s --but they will also send the bad guys plans spiraling into complete disaster because their goals don't involve unleashing an EldritchAbomination on the world.
* ''[[VideoGame/FirstEncounterAssaultRecon Fear 2: Project Origin]]'' has this happen to the player instead of the villain. Terry Halford comes up with a [[AppliedPhlebotinum telesthetic amplifier]] that could give the player character, Sergeant Beckett, a decent chance at [[BattleInTheCenterOfTheMind exploding Alma's head]], and then [[spoiler:Genevieve Aristide waltzes in, shoots any dissenting voices, and changes the amplifier's settings in an attempt to [[SealedEvilInACan trap Alma]]. Note that Halford, who has a far better grasp of the math and science of the amplifier, has already stated very emphatically that Aristide's plan simply will not work and Aristide is essentially a desperate idiot trying to make reality conform to her wishes. Her pitiful attempts only make Alma stronger, at [[MindRape your expense]].]]
* In ''VideoGame/VampireTheMasqueradeBloodlines'', the player character skews the [[GambitPileup very, very delicate power balance of Los Angeles]] simply by being Embraced. That's about the only time things are ''not'' going according to someone's plan, though, and is directly followed by XanatosSpeedChess on the part of Jack, [=LaCroix=] and [[spoiler: Caine]], rather than a VillainousBreakdown on anyone's part. [[spoiler: In the endgame, it is impossible for you to be one, because [[XanatosGambit whatever you do, LaCroix is toast for one reason or another]].]]

* Speaking of Sierra, the Hero in the ''VideoGame/QuestForGlory'' series tends to be this at times as well, either by intent or accident. Basically all of ''VideoGame/QuestForGloryIV'' was a result of the teleport spell used to snatch him at the end of ''VideoGame/QuestForGloryIII'' dumping him in the wrong place in Mordavia.
* Sierra loved this one, because much of ''VideoGame/SpaceQuest'' ran on this as well. Roger Wilco had just the good (or bad) luck to send the best laid plans careening into a cliff.
** [[VideoGame/SpaceQuestITheSarienEncounter The first game]]? The Sarians had boarded the ''Arcadia'', stolen the Star Generator, and slaughtered all of the crew...except Roger, who had been taking an unscheduled nap in the broom closet.
** [[VideoGame/SpaceQuestIIVohaulsRevenge The second game]]? Vohaul had his cloned army (granted, they were an army of insurance salesmen) ready for launch, but having his {{Mook}}s sent to kill Roger in an attempt to ''prevent him'' from stopping it (after all, Vohaul bankrolled the Sariens), led to Roger showing up and [[NiceJobFixingItVillain wrecking the plan anyway]].
** [[VideoGame/SpaceQuestIIIThePiratesOfPestulon Third game]]? Roger was just good enough at Astro-Chicken and just bored enough to find and investigate the secret message from Pug's captive programmers.
** [[VideoGame/SpaceQuestIVRogerWilcoAndTheTimeRippers Fourth game]]? Once again, Vohaul tries to pre-emptively kill Roger from screwing up the plan. But the timely arrival of Xenon's time-traveling LaResistance sends that into a tailspin.
** [[VideoGame/SpaceQuestVTheNextMutation Fifth game]]? Captain Quirk was above suspicion, captain of the Confederation flagship. No one was going to investigate some toxic waste dumps on a few backwater planets. They all but laughed the ambassador representing those backwaters out of the room when she tried to call attention to the problem. But then a mouse chews up some wires in the academy computer, Roger gets accidentally promoted to Captain, and guess who finds out about Quirk's lucrative side business in transporting teratogenic sludge?
** [[VideoGame/SpaceQuestVIRogerWilcoInTheSpinalFrontier Sixth game]]: Stellar is the spanner. Sharpei wanted to commit GrandTheftMe on Roger, figuring he wouldn't be missed. But Stellar steps in at the last minute, makes a HeroicSacrifice, and Roger decides he's going to rescue his pal. Sharpei and her plan did not survive.
* ''Franchise/FireEmblem''
** In ''VideoGame/FireEmblemGenealogyOfTheHolyWar'', [[spoiler: Manfroy's StalkerWithATestTube plan to have the perfect SoulJar for EvilGod Loptyr]] ''did'' work… but was thrown off by [[spoiler: how the mother of said SoulJar gave birth to ''twins''... and the sister of the SoulJar actually had the [[HeroicLineage Sacred Blood]] needed to handle the perfect weapon to ''vanquish Loptyr away''. And then the girl was spirited away by her dying mother and later was ''adopted'' by LaResistance… led by her and her twin's older half-brother, a boy who ALSO has Sacred Blood ''and'' is getting ready to go against the Empire...]]
** ''VideoGame/FireEmblemTheBlazingBlade'' has [[spoiler: Kishuna]] and [[spoiler: Hector]]. The first one ruins a SmugSnake magic user's trap for the heroes [[spoiler: via his AntiMagic powers]], while the second is such a strong support for Eliwood that [[spoiler: Nergal]] has to admit that his mere presence throws his gambits around Eliwood off.
** In ''VideoGame/FireEmblemAwakening'', one of these appeared in the backstory. [[spoiler: The Grimleal aka the local ReligionOfEvil has carried a SuperBreedingProgram for at least four generations, trying to have a baby conceived with enough Grima blood in him/her to get the full mark and thus make him/her the perfect [[GrandTheftMe host]] for Grima. They didn't count, however, on the mother of the last baby ''and'' most perfected Grima prospect vessel running away with the baby. It's unclear if the mother was part of the religion or not.]] Thanks to this, [[spoiler: the prospect vessel grew away from the ReligionOfEvil... and became [[PlayerCharacter the Avatar]] aka ''the Protagonist of the game''.]]
** In ''VideoGame/FireEmblemFates'', King Garon plans to have the Avatar killed. Too bad the two times he expresses such a desire, it's when someone else is in his vicinity: [[spoiler: Xander]] (in ''Conquest'') and [[spoiler: Elise]] (in ''Revelation''). Both of them decide to work against it, by either [[spoiler: sending reinforcements to spoil an UriahGambit]] in the first case, or by [[spoiler: secretly sneaking out of the castle to join the "traitor" anyway]] in the second.
** In ''VideoGame/FireEmblemThreeHouses'' The Flame Emperor [[spoiler: Edelgard]] hires bandits to attack the Lord characters at the start of the game. However, instead of staying and fighting them off and being killed, Claude (one of the Lord characters targeted) simply runs off and he and the other two lords, Dimitri and Edelgard, will run into [[PlayerCharacter Byleth]] starting off the plot of the game.

* In ''[[VideoGame/NintendoWars Advance Wars 2]]'', despite Andy having a spanner himself, [[spoiler: It's Hawke's turn against Sturm that really destroys his plans.]]
* In the chapter 1 finale of ''VideoGame/DragonFable'', the BigBad is undone by two spanners. [[spoiler:The Bacon Elemental Orb (which no one but Cysero knew even existed until that moment) combined with Cysero's time machine]] gives the hero and his dragon a fighting chance in the FinalBattle. Just when it seems like even that wouldn't be enough to save the day, [[spoiler:the villain's host body Fluffy reveals his [[AttackItsWeakPoint weak point]] to the hero and his dragon.]]
* ''VideoGame/GrimGrimoire'' has the TheArchmage preparing to break free from his SoulJar and take the philosopher's stone and menace the world, and powerful devil he entered a pact with named Grimlet is about ready to break from being sealed inside the old wizard Gammel Dore. Neither of them could possibly predict that both of their plans would screwed up by one CuteWitch named Lillet Blann caught in GroundhogDayLoop.
* ''VideoGame/TheElderScrollsVSkyrim'':
** The Dragonborn is the spanner in ''several'' works by different individuals or factions.
*** Assuming the player never discovers [[spoiler:the Dossier revealing the Thalmor's role in the civil war]], the [[PlayerCharacter Dragonborn]] can become this for [[spoiler:the Thalmor]], who are running a long scheme to weaken their enemies by goading Ulfric Stormcloak into rebelling against the Empire and making sure the civil war goes on for as long as possible to drain both sides' strength. The Dragonborn can end the war with one of two outcomes, both of which are bad news for [[spoiler:the Thalmor]]. They can then take it a step further by [[spoiler: assassinating their leader Elenwen after the main quest line is clear and she loses her essential status.]]
*** In the [[MurderInc Dark Brotherhood]] questline, the Dragonborn is this for Astrid. The Dragonborn is the Night Mother's unwitting chosen one, which screws over Astrid's position as the "family don."
*** The Ebony Blade was locked safely away in Whiterun, from champions who would be tempted into killing their loved ones and confidants to empower a stupid sword and go murderously insane... until the Jarl's son became a talkative ass from the sword spirit's rumors. The Dragonborn figures out how to steal the sword, thanks to the boy blabbing about the "woman behind the door."
*** In an odd case, the Dragonborn does this twice in the ThievesGuild questline. First, they and Mercer move to take down Karliah, only for the Dragonborn to be shot by her with an arrow laced with paralysis poison. Mercer takes the opportunity to stab the Dragonborn and return to the guild, leaving Karliah to rescue the Dragonborn and explain that the arrow was intended for Mercer, to take him back to Nocturnal for judgement - but the appearance of another person was unexpected, so she attacked the Dragonborn to save them from Mercer's [[Series/{{Firefly}} sudden but inevitable betrayal]]. This sets off a sequence of events in which the Dragonborn, Brynjolf, and Karliah all take down Mercer together. By being a spanner in the works for Karliah, the Dragonborn ends up being the one to undo all of Mercer's plans, just by getting being unfortunate enough to get caught up in his scheme.
*** The Dragonborn does this ''again'' in the Mage College questline. By being the only one who has ever tried to investigate what happened at Labyrinthian, they're the one who uncovers what Ancano is really trying to do. The Psijic Order helps a bit, but it's mostly the Dragonborn doing the spanning.
** [[BigBad Alduin]] for General Tullius and the Imperials. Tullius managed to capture Ulfric Stormcloak, the leader of the Nordic rebellion which had almost managed to rout the Empire completely from Skyrim before Tullius arrived to head the Legion forces there. Had Alduin not shown up during the Stormcloak execution, it's likely that the Empire would have won the Civil War not long afterward. Ironically, Alduin's arrival is what saves the life of the Dragonborn, which also makes Alduin an indirect spanner in the works in all of the instances listed above.
* As of ''[[VideoGame/BlazBlue BlazBlue: Continuum Shift Extend]]'', Terumi's master {{gambit pileup}} for his goals remained untouched up until [[spoiler:Makoto Nanaya fell into one particular timeline by accident and interfered with events key to his schemes - the end result being utter annulment of all of his plans in that timeline, and she got away with it with help from Rachel Alucard. As a result, from ''Continuum Shift'' proper onward, Terumi's plans for Makoto have changed from "keep away from Tsubaki and Noel" to "outsource to Relius or kill on sight".]]
** This is actually a {{reconstruct|edTrope}}ion. [[spoiler:Makoto's Spanner status comes from the fact that she never knew Noel never existed in this timeline up until Terumi's plans had already fallen apart. Other than that, she had proven through the entire story that she was capable of picking up on the world around her and using the intel she accumulated to formulate and rebuild her plans on a whim - one slip of the tongue by Terumi was enough for her to, with help from Bang's keen-eyed disciple, figure out that Relius was luring her into a trap and adjusted her plans just enough to defuse the problem and keep at work. Had she known about that missing fact any time before she ran into Tsubaki, she could have {{outgambitted}} Terumi instead.]]
* In ''VideoGame/KingdomsOfAmalurReckoning'', The Fateless One is this to everyone and everything because he/she is ImmuneToFate. Furthermore, since he/she was a BlankSlate with no memories upon revival it's impossible to predict just how he/she will react in any given situation. Everyone who tries to manipulate the Fateless One for their own evil plans fails miserably. [[spoiler:Even Tirnoch, the being that allowed the Fateless One to exist in the first place, underestimates what she created and pays for it with her life.]]
* This is generally the case in every mainline ''Franchise/{{Pokemon}}'' game, with the player character acting as the spanner. Every villain team's plans get ruined because a small town kid recently started their adventure and managed to get mixed into the events due to [[RightManInTheWrongPlace just being in the area at the time]] (e.g. ''VideoGame/PokemonRedAndBlue'') or becoming friends with someone who knows the villain (e.g. ''VideoGame/PokemonSunAndMoon'').
** The evil scheme of ''VideoGame/PokemonBlackAndWhite'' goes off the rails the moment [[spoiler: Ghetsis's LaserGuidedTykebomb N discovers that {{humans|AreTheRealMonsters}} ''[[AvertedTrope aren't]]'' [[HumansAreTheRealMonsters bastards]], shaking his worldview and forcing him to reevaluate his cause]], purely by encountering the player character in the second town.
** In the fangame ''VideoGame/PokemonReborn'', this happens to the villainous team, Team Meteor, at the very start of the game: [[spoiler: they were one terrorist attack away from destroying Reborn City's power plant and plunging it into anarchy, allowing them to carry out their EvilPlan, but two things happened: first, a grunt got captured after bombing a train station in an effort to keep people from entering the city, and fessed up about Team Meteor's plans, allowing the Gym Leaders to stop the destruction of the power plant; and second, the PlayerCharacter arrived and began to systematically foil their plans one by one, usually because they got dragged into foiling them by their new friends.]]
** ''[[VideoGame/PokemonDiamondAndPearl Pokemon Platinum]]'' might be the most notable example for the series. Team Galactic were seconds away from victory - the protagonist and rival were just a bit too late to Spear Pillar, and the Champion was still en route. The universe should have been destroyed... [[spoiler:except that Cyrus didn't realise there was a ''third'' cosmic dragon around, as it was so horrific that even the mythology of Sinnoh never mentioned it. Said dragon - Giratina - opens up a portal to the Distortion World right in front of Cyrus and pulls him, plus the three lake guardians, into its world. This breaks Cyrus's control over Palkia and Dialga and ultimately stops him from remaking reality.]]
* In ''VideoGame/MaxPayne 3'', Max was the perfect UnwittingPawn. A dumb gringo who'd been steered into making many enemies, he would be hopelessly lost at best, soon dead at worst. Unfortunately for the villains, good cop Da Silva showed up and gave him direction, and their plans started falling apart soon afterwards.
* In ''VideoGame/DevilSurvivor2'' the Main Character can be this for [[spoiler: Yamato and/or Polaris]] by choosing another faction when [[spoiler: Yamato probably would have won if not for the Main Character's interference]] and possibly [[spoiler: convince Alcor to help kill Polaris and end Polaris' system]].
* In ''VideoGame/DawnOfTheDragons'', the dragons' long-running scheme to reconquer the world is derailed by two spanners. The first is a crazy wizard who wakes them up too early because he wanted to use them in his own scheme for world conquest. The second is the player character, an ordinary farmhand who frees an unborn dragon from his evil parents' influence and assembles an army alongside the newborn.
* The modern day ''Franchise/SonicTheHedgehog'' games seem to have given Dr. Eggman these moments as he'd be close to victory, then something happens that turns everything on its head.
** For ''VideoGame/SonicAdventure'', it's Chaos not taking Eggman's crap anymore.
** For ''VideoGame/SonicAdventure2'', it's that the Eclipse Cannon had a Doomsday Protocol that activated when all the Chaos Emeralds are gathered in it.
** For ''VideoGame/SonicForces'', it's Infinite dropping a Prototype Phantom Ruby during his fight with Silver, which is then [[ChekhovsGun later used]] to [[spoiler: nullify the cannons Infinite tried to use to kill the Avatar, and to delete the fake sun that Infinite and Eggman tried to drop on the planet.]]
* ''VideoGame/TronTwoPointOh'': The F-Con CEO had been planning his takeover of Encom and invasion of {{cyberspace}} with Datawraith mercenaries for ''twenty years.'' (It's implied that he was Edward Dillinger from [[{{Film/Tron}} the first film]], out for payback after being forced out of Encom in disgrace). Things would have gone swimmingly... if Alan Bradley hadn't been arguing with his son [[SpinOffspring Jethro]] at the time F-con's thugs burst in the room and kidnapped him, and if Jethro hadn't been standing in just the right spot for [=Ma3a=] to kidnap ''him'' via Shiva laser.

* In ''VideoGame/BaldursGate'', the protagonist spoils Bhaal's planned resurrection as well as all the plans of three other {{Big Bad}}s simply by surviving against all odds, and growing from a nobody orphan to one of the most powerful beings in the Forgotten Realms in the process. Late in ''Throne of Bhaal'', the Solar reveals that the protagonist being the spanner in Bhaal's works has been predicted by Alaundo's prophecy.
* In ''VideoGame/CastleRed'', the BigBad, [[spoiler: Howard]], when confronted with the upcoming Trial of the Worm, set things up so that none of the other participants would even know about the Trial, allowing him to toy with them for his own amusement without risking [[spoiler: losing his status as Lord.]] However, the first step of this plan was to [[ParasiteZombie infest all the castle's servants with worms]], but he never expected that [[spoiler: one of the servants, the maid Margaery, would be strong enough to bond with the worms and retain her sentience. This meant that there was now, unbeknownst to him, someone else in the castle who knew about the trial, knew what he really was, and who also had a vendetta against him. Once he realizes that Margaery exists and has already made contact with the other participants, he is forced to change his plans, eventually exposing himself as Lord, leading to his death at Jonathon's hands in half the endings.]]
* In ''VideoGame/StarCraft'', the schemes of the GreaterScopeVillain [[spoiler:fallen Xel'naga Amon]] were derailed by a few ships carrying tens of thousands of human prisoners/colonists that overshot their target destination and crash-landed in the Koprulu Sector. This accident introduced a race of stubborn idiots who quickly became a power rivaling the Protoss and the Zerg [[spoiler:and the only ones who Amon wasn't able to control en masse through some psychic leash like the Khala and the Zerg Overmind.]] The schemes that [[spoiler:Amon and Duran]] tried to exploit them had some short-term success but ultimately resulted in nothing more than [[spoiler:the creation of the very beings who would kill them. Kerrigan slays Amon, while Stukov slays Duran.]]
* Manny from ''VideoGame/GrimFandango'' steals one of his rival coworker's clients out of jealousy at the beginning of the game, and in the process uncovers, and eventually completely dismantles, a crime boss's long-running scheme to steal peoples' eternal rewards.
* This is Flemeth's role in ''VideoGame/DragonAgeOrigins''. The only thing preventing both the human BigBad and the Archdemon from succeeding in their respective plots is the fact that two young Grey Wardens survive the disaster that was the Battle of Ostagar, and go on from there to save the world. And the reason they survive is Flemeth.
** Similarly, the Inquisitor is the resident spanner for the BigBad in ''VideoGame/DragonAgeInquisition''. The one person who survives the massive explosion at the beginning of the game is the one person able to stop his plans.
* ''VideoGame/MassEffect'' has one in the form of a dock worker on the colony being attacked in the prologue mission. [[TheDragon Saren]] finds his comrade Nilus and murders him to keep him from interfering with his plan. The dock worker saw the whole thing and promptly told Shepard when they showed up. The only reason the dock worker was even still alive was because he was napping behind a wall of shipping crates when the attack happened. He was concealed from the notice of Saren and the geth, and was in the perfect position to witness the murder. Without him, no one would have caught on to Saren's plans until it was too late.
** Shepard qualifies throughout the franchise in regards to the Reaper cycle. Every 50,000 years, the Reapers descend from on high and launch the systematic genocide of every sentient, space-faring species, organic or synthetic, because [[spoiler: that was the solution they came up with for their creator's concern about the inevitability of organic vs. synthetic race wars]]. While they are used to resistance, they still successfully complete the culling and leave. Then comes Shepard, who aids or spearheads the destruction of several Reapers and [[spoiler: finds a way to either destroy them completely, control them, or merge organic and synthetic life to render their mission statement obsolete]].
** Just before the climactic mission of the second game, ship's {{AI}} EDI discusses this trope for why it's important to have organic minds involved in decision making, to figure in the possibility of tactical and[=/=]or strategic errors:
-->''Calculating an optimum course of action is simple. If two A.I. weapons are pitted against each other, the one with superior hardware will always win. Human misjudgements defy predictive models.''
* In ''Videogame/GodOfWarPS4'', it's implied that Kratos's very presence (due to [[spoiler: being a Greek God in a Norse world]]) in Midgard is causing some reality-bending and literal fate-defying issues, resulting in him breaking and changing prophesied events, to the shock of Aesir gods. So far, Kratos has been indirectly related to or directly responsible for: [[spoiler: the deaths of Magni and Móði (both of whom were fated to survive Ragnarök), the death of Baldur (not supposed to happen for ''hundreds'' of years) and triggering the start of Fimbulwinter (which heralds Ragnarök, having come hundreds of years too early).]]
** In addition to the above, because he arrived in Midgard, [[spoiler: he met and married Faye, the last Frost Giant, and fathered Atreus (who is none other than ''Loki'' who is the one to kickstart Ragnarok and bring about the end of the Aesir gods).]]
** Sindri gifted Atreus with [[spoiler: mistletoe arrows]], which were directly the cause of [[spoiler: breaking Baldur's immortality after Baldur punched Atreus and a mistletoe arrowhead holding Atreus's strap pieces Baldur's hand.]]

* ''VideoGame/LeisureSuitLarry2LookingForLoveInSeveralWrongPlaces'': So much. Of the unaware variety. Seriously, [[IdiotHero Larry]] ends up screwing Nonookee's plot without ever being aware of it, and to add insult to injury, kills him by accident.
* In the ''Franchise/{{Kirby}}'' series, the titular pink blob often plays this role if he's not being an UnwittingPawn; something will disturb his usual peace, he'll go out to find out why, only to run into the BigBad or their minions, and promptly derail or outright foil their plans entirely.
** He also plays this role in ''VideoGame/SuperSmashBrosUltimate'' — were it not for his escape, Galeem would have destroyed the video game multiverse.
* The player character in ''VideoGame/FinalFantasyAdventure''. He's not destined in any way, he's not descended from any sort of important lineage, and he doesn't even have any great aspirations at the beginning of the game outside of escaping from the Dark Lord's gladiator pens. Because he's such a non-entity, though, the Dark Lord's continuing plans to destroy his opposition and cement control over the world [[spoiler: and later, after Dark Lord's death, Julius' plans to do the same]] overlook that one escaped slave, and he's ultimately able to save the world, [[BittersweetEnding albeit at great cost]].
* ''VideoGame/RedDeadRedemption2'': [[spoiler:Believe it or not, Micah Bell's death was what helped to kickstart the events of the first ''VideoGame/RedDeadRedemption''. Because John Marston came out of hiding to hunt Micah down for Arthur Morgan's death, he once again brought himself under the radar of the Pinkertons, and allowed Edgar Ross to track him down.]]
* The ''[[UpdatedRerelease Full Body]]'' version of ''{{VideoGame/Catherine}}'' introduces Rin, a potential third romantic option. Rin is sweet, earnest, supportive, naive, and completely harmless. She's suffering from amnesia and has little idea of how the world works; she just wants to play the piano and make people happy. She's not directly involved with the main love triangle, and the other two women barely even notice her. [[spoiler: Even the BigBad thinks Rin isn't a threat to his plan, despite knowing they're from a race of AngelicAliens merely posing as a human. Given that the BigBad's scheme focuses on killing off uncommitted/cheating men, the fact that [[OtokonokoGenre Rin's human form is an androgynous male]] made it highly unlikely they'd be a problem. He even hires them to play at The Stray Sheep!]] She's open-minded and has some unusual - but profound - ideals: No one can tell someone else how to live their life, and that individuals are the only ones should decide what is important to them. If you choose to romance Rin, [[spoiler: this philosophy turns out to be ''exactly'' what Vincent needs to hear to take a step back from the whole Katherine/Catherine debacle and reassess his life.]] Not only does Vincent become a far stronger, more competent person, he [[spoiler: realizes [[IfItsYouItsOkay Rin makes him happy and that gender doesn't matter to him.]]]] This ''completely'' derails [[spoiler: Catherine's plan; [[DidntSeeThatComing she isn't even aware of Rin as a romantic rival until it's too late]], and [[KnowWhenToFoldEm just gives up]] when she realizes [[IncompatibleOrientation Vincent may not even be interested in being seduced by a woman.]]]] Also, the BigBad made a huge mistake by [[spoiler: hiring Rin as The Stray Sheep's pianist; their angelic power creates MagicMusic that slows down the Nightmare and allows its listeners to think of new opportunities and possibilities. Better emotional stability and less stress makes the Nightmare far easier to handle.]] By the end of the final challenge, Vincent and Rin's relationship is so strong, they [[spoiler: easily counter Mutton's homophobic rant with a heartfelt KirkSummation. And that's before Rin's Big Brother zaps him into submission in the True Ending.]] Vincent could've survived the ordeal on his own, but Rin was the one who made that victory inevitable.
* ''VideoGame/DragonQuestXI'' features two villainous characters who [[EvilVersusEvil serve as this to each other]]. [[spoiler:Mordegon was this to Calasmos in the second act. When Erdwin's Lantern, the prison containing the body of Calasmos, begins falling from the sky, Mordegon destroys the lantern to ensure that he alone rules Erdrea. In the postgame, Calasmos returns the favor by preventing Mordegon from stealing the Sword of Light while possessing King Carnelian, which inadvertently exposes him as Mordegon.]]
* In a sense, the Courier of ''VideoGame/FalloutNewVegas'' is this (or at least has the option to be). After getting shot in the head by a mysterious man and literally dug from the grave by a friendly cowboy robot, the Courier begins their journey across the Wasteland to retrieve a platinum poker chip stolen from them by the aforementioned man and possibly exact some form of revenge. [[spoiler:Said platinum chip turns out to be a key component in completing Mr. House's plan. After retrieving it, the Courier has the option of delivering it to him as agreed or using it against him to overthrow Mr. House.]] The Courier also has the option of basically saying "screw you" to most if not all of the Mojave's major factions, earning the Independent Ending.
* In ''VideoGame/LuigisMansion3'', Polterpup helps Luigi at various moments, but most notably before the final battle when [[spoiler:he pushes Luigi out of the way of the portrait King Boo slammed down on Mario and Peach. King Boo doesn't even seem to notice [[BeneathNotice Polterpup.]]]]
** Helen Gravely also inadvertently creates her own spanner by inviting Professor E. Gadd to the hotel under the pretense of holding a ghost convention in order to kidnap him. While this seems like a great idea, as E. Gadd's inventions are responsible for capturing King Boo as well as other ghosts, E. Gadd decided that he not only would he bring along some ghost portraits to show off at the 'convention', he'd also bring Gooigi and the latest Poltergust G-00 too, [[NiceJobFixingitVillain the very thing needed to defeat King Boo.]]
* Agent Brown is this for the BigBad in the first ''VideoGame/DetectivesUnited'' game - and unlike many examples, he's a spanner on purpose. [[spoiler:The only thing preventing the BigBad from putting together his ArtifactOfDoom is his inability to find Azazel, one of the mystic stones needed for the project. Azazel is bound into a bracelet and kept by the members of the Mystery Trackers organization, of which Agent Brown is one. Prior to the beginning of the adventure, he suspects that this MacGuffin might be important, and so he takes it with him... thus keeping it out of the BigBad's hands when he storms Mystery Trackers HQ.]]

** He also plays this role in ''VideoGame/SuperSmashBrosUltimate'' — were it not for his escape, Game Over Galeem would have destroyed the video game multiverse.

* ''Franchise/ShinMegamiTenseiPersona'':

* ''VideoGame/YesYourGrace'': At some point, a chalice of poisoned wine turns out to have killed someone else than its intended target because someone inadvertently switched two chalices while searching the table for somehting small among the items present on the table.

* ''VideoGame/YesYourGrace'': At some point, a chalice of poisoned wine turns out to have killed someone else than its intended target because someone inadvertently switched two chalices while searching the table for somehting small among the items present on the table.

* Agent Brown is this for the BigBad in the first ''VideoGame/DetectivesUnited'' game - and unlike many examples, he's a spanner on purpose. [[spoiler:The only thing preventing the BigBad from putting together his ArtifactOfDoom is his inability to find Azazel, one of the mystic stones needed for the project. Azazel is bound into a bracelet and kept by the members of the Mystery Trackers organization, of which Agent Brown is one. Prior to the beginning of the adventure, he suspects that this MacGuffin might be important, and so he takes it with him... thus keeping it out of the BigBad's hands when he storms Mystery Trackers HQ.]]

** ''VideoGame/Persona5'': [[spoiler:Akechi]] ends up being the fatal flaw in [[spoiler:Shido]]'s chain of operations once the team recalls he overheard a specific part of a conversation that he shouldn't have been able to hear. Which was [[spoiler:Morgana's ability to be heard by humans after being in the Metaverse]], allowing the team to outmaneuver his plans and trick him into revealing the name of his employer.

* The Alien protagonist in ''[[VideoGame/AliensVsPredator Aliens vs. Predator 2]]''.

* ''VideoGame/{{Persona 3}}''. After his [[TheReveal Reveal]] as TheChessmaster, [[spoiler:Shuji Ikutsuki]] plans to sacrifice most of the party by [[spoiler:forcing RobotGirl Aigis to murder them]] in order to bring about TheEndOfTheWorldAsWeKnowIt. He's just about to succeed... but at that point, the player is reminded that he forgot to crucify the dog, too.

** Calia Menethil becomes this in the ''Literature/BeforeTheStorm'' novel. Its central plot revolves around King Anduin Wrynn setting up a reunion of undead Forsaken and their human loved ones, separated by the fall of Lordaeron. Calia is the last living member of Lordaeron's royal family, and her being recognized is a concern because it might bring up more problems than it solves now that Lordaeron is the kingdom of the undead. Despite this, she makes a case to be allowed to attend the gathering itself and help with the reunions. However, one of the Forsaken there [[spoiler:recognizes her, and that recognition starts a chain of events that leads to the deaths of every Forsaken in attendance and Calia herself, all at the hands of the Forsaken leader Sylvanas Windrunner, who immediately assumes that Calia, once she's revealed, is there as a usurper, and isn't entirely wrong either]].

** Just before the climactic mission of the second game, ship's {{AI}} EDI discusses this trope for why it's important to have organic minds involved in decision making, to account for possible tactical and[=/=]or strategic errors:

** Just before the climactic mission of the second game, ship's {{AI}} EDI discusses this trope for why it's best to have organic minds involved in decision making:

*** In an odd case, the Dragonborn does this twice in the ThievesGuild questline. First, he and Mercer move to take down Karliah, only for the Dragonborn to be shot by her with an arrow laced with paralysis poison. Mercer takes the opportunity to stab the Dragonborn and return to the guild, leaving Karliah to rescue the Dragonborn and explain that the arrow was intended for Mercer, to take him back to Nocturnal for judgement - but the appearance of another person was unexpected, so she attacked the Dragonborn to save them from Mercer's [[Series/{{Firefly}} sudden but inevitable betrayal]]. This sets off a sequence of events in which the Dragonborn, Brynjolf, and Karliah all take down Mercer together. By being a spanner in the works for Karliah, the Dragonborn ends up being the one to undo all of Mercer's plans, just by getting being unfortunate enough to get caught up in his scheme.

* In ''VideoGame/SuperRobotWarsOriginalGeneration Gaiden'', Duminuss' plan was that ''real'' close to break up the spirit of EFA. First, it got hold of Lamia and brainwashed her to the point of no return and would make her blow herself up just to rub in the fact that Kyosuke cannot fulfill his promise to her. That failed, and later, Lamia managed to return to EFA, good as new. How? Apparently Duminuss failed to notice that that Axel [[BackFromTheDead just took a U-Turn from his journey to hell]], and [[HeelFaceTurn has an adjustment]] [[GracefulLoser in personality]] and, being another last survivor of Shadow Mirror, he just happens to have the one thing that could reset Lamia and undo all of Duminuss' machinations, and just in case Kyosuke does not break into a world-destroying maniac out of despair (it happened in his world), Axel uses that thing pronto.

** [[BigBad Alduin]] for General Tullius and the Imperials. Tullius managed to capture Ulfric Stormcloak, the leader of the Nordic rebellion that had almost managed to rout the Empire completely from Skyrim before Tullius arrived to head the Legion forces there. Had Alduin not shown up during the Stormcloak execution, it's likely the Empire would have won the Civil War not long after.
** Assuming the player never discovers [[spoiler:the Dossier revealing the Thalmor's role in the civil war]], the [[PlayerCharacter Dragonborn]] can become this for [[spoiler:the Thalmor]], who are running a long scheme to weaken their enemies by goading Ulfric Stormcloak into rebelling against the Empire and making sure the civil war goes on for as long as possible to drain both sides' strength. The Dragonborn can end the war with one of two outcomes, both of which are bad news for [[spoiler:the Thalmor]]. They can then take it a step further by [[spoiler: assassinating their leader Elenwen after the main quest line is clear and she loses her essential status.]]
** In the Dark Brotherhood (Assassin's Guild) Questline, the Dragonborn can also be this for Astrid. The Dragonborn is the Night Mother's unwitting chosen one, which screws over Astrid's position as the "family don."
** The Ebony Blade was locked safely away in Whiterun, from champions who would be tempted into killing their loved ones and confidants to empower a stupid sword and go homicidally insane... until the Jarl's son became a talkative ass from the sword spirit's rumors. The Dragonborn figures out how to steal the sword thanks to the boy blabbing about the "woman behind the door."
** In an odd case, the Dragonborn does this twice in the Thieves' Guild questline. First, he and Mercer move to take down Karliah, only for the Dragonborn to be shot by her with an arrow laced with paralysis poison. Mercer takes the opportunity to stab the Dragonborn and return to the guild, leaving Karliah to rescue you and explain that the arrow was intended for Mercer, to take him back to Nocturnal for judgement, but your appearance was unexpected, so she attacked you to save your life from Mercer's inevitable betrayal. This sets off a sequence of events in which you, Brynjolf, and Karliah all take down Mercer together. By being a spanner in the works for Karliah, you ended up being the one to undo all of Mercer's plans, just by getting being unfortunate enough to get caught up in his scheme.

** For ''Videogame/SonicForces'', it's Infinite dropping a Prototype Phantom Ruby during his fight with Silver, which is then [[ChekhovsGun later used]] to [[spoiler: nullify the cannons Infinite tried to use to kill the Avatar, and to delete the fake sun that Infinite and Eggman tried to drop on the planet.]]
* ''VideoGame/TronTwoPointOh'': The F-Con CEO had been planning his takeover of Encom and invasion of {{cyberspace}} with Datawraith mercenaries for ''twenty years.'' (It's impled he was Edward Dillinger from [[{{Film/Tron}} the first film]], out for payback after being forced out of Encom in disgrace). Things would have gone swimmingly...if Alan Bradley hadn't been arguing with his son [[SpinOffspring Jethro]] at the time F-con's thugs burst in the room and kidnapped him, and if Jethro hadn't been standing in just the right spot for [=Ma3a=] to kidnap ''him'' via Shiva laser.
* In ''VideoGame/SuperRobotWarsOriginalGeneration Gaiden'', Duminuss' plan was that ''real'' close to break up the spirit of EFA. First, it got ahold of Lamia and brainwashed her to the point of no return and would make her blow herself up to rub the fact that Kyosuke cannot fulfill his promise to her. That failed and later on Lamia managed to return to EFA, good as new. How? Apparently Duminuss failed to notice that that Axel [[BackFromTheDead just took a U-Turn from his journey to hell]], and [[HeelFaceTurn has an adjustment]] [[GracefulLoser in personality]] and, being another last survivor of Shadow Mirror, he just happens to have the one thing that could reset Lamia and undo all of Duminuss' machinations, and just in case Kyosuke does not break into a world-destroying maniac out of despair (it happened in his world), Axel uses that thing pronto.

* ''VideoGame/LeisureSuitLarry2LookingForLoveInSeveralWrongPlaces'': So much. Of the unaware variety. Seriously, [[IdiotHero Larry]] ends up screwing Nonookee's plot without ever being aware of it, and to add insult to injury, kill him by accident.
* And in the ''Franchise/{{Kirby}}'' series, the titular pink blob often plays this role if he's not being an UnwittingPawn; something will disturb his usual peace, he'll go out to find out why, only to run into the BigBad or their minions, and promptly derail or outright foil their plans entirely.
** He also plays this role in ''VideoGame/SuperSmashBrosUltimate''—were it not for his escape, Game Over Galeem destroyed the video game multiverse.

* In a sense, the Courier of VideoGame/FalloutNewVegas is this (or at least has the option to be). After getting shot in the head by a mysterious man and literally dug from the grave by a friendly cowboy robot, the Courier begins their journey across the Wasteland to retrieve a platinum poker chip stolen from them by the aforementioned man and possibly exact some form of revenge. [[spoiler:Said platinum chip turns out to be a key component in completing Mr. House's plan. After retrieving it, the Courier has the option of delivering it to him as agreed or using it against him to overthrow Mr. House.]] The Courier also has the option of basically saying "screw you" to nearly if not all of the Mojave's major factions, earning the Independent Ending.
* In ''VideoGame/LuigisMansion3'', Polterpup helps out Luigi at various moments but most notably before the final battle when [[spoiler:he pushes Luigi out of the way of the portrait King Boo slammed down on Mario and Peach. King Boo doesn't even seem to notice [[BeneathNotice Polterpup.]]]]
** Hellen Gravely also inadvertently creates her own spanner by inviting Professor E. Gadd to the hotel under the pretence of holding a ghost convention in order to kidnap him. While this seems like a great idea as E. Gadd's inventions are responsible for capturing King Boo as well as other ghosts, E. Gadd decided that he not only would he bring along some ghost portraits to show off at the 'convention', he'd also bring Gooigi and the latest Poltergust G-00 too, [[NiceJobFixingitVillain the very thing needed to defeat King Boo.]]
----

** [[BigBad King Boo]] also inadvertently creates his own spanner by inviting Professor E. Gadd to the hotel under the pretence of it holding a ghost convention in order to kidnap him. While this seemed like a great idea as King Boo recognises the trouble that E. Gadd has caused him previously, E. Gadd decided that he would bring along some ghost portraits to show off at the 'convention', including the latest Poltergust G-00, [[NiceJobFixingitVillain the very thing needed to defeat King Boo.]]

* In [[VideoHGame/LuigisMansion3]], Polterpup helps out Luigi at various moments but most notably before the final battle when [[spoiler:he pushes Luigi out of the way of the portrait King Boo slammed down on Mario and Peach. King Boo doesn't even seem to notice [[BeneathNotice Polterpup.]]]]

** [[VideoGame/SpaceQuestVIRogerWilcoInTheSpinalFrontier Sixth game]]: Stellar the the spanner. Sharpei wanted to commit GrandTheftMe on Roger, figuring he wouldn't be missed. But Stellar steps in at the last minute, makes a HeroicSacrifice, and Roger decides he's going to rescue his pal. Sharpei and her plan did not survive.

** Assuming the player never discovers [[spoiler:the Dossier revealing the Thalmor's role in the civil war]], the [[PlayerCharacter Dragonborn]] can become this for [[spoiler:the Thalmor]], who are running a long scheme to weaken their enemies by goading Ulfric Stormcloak into rebelling against the Empire and making sure the civil war goes on for as long as possible to drain both sides' strength. The Dragonborn can end the war with one of two outcomes, both of which are bad news for [[spoiler:the Thalmor]].

* ''VideoGame/MassEffect'' has one in the form of a dock worker on the colony being attacked in the prologue mission. [[TheDragon Saren]] finds his comrade Nilus and murders him to keep him from interfering with his plan. The dock worker saw the whole thing and promptly told Shepard when they showed up. The only reason the dock worker was even still alive was because he was napping behind a wall of shipping crates when the attack happened. He was concealed from the notice of Saren and the geth, and was in the perfect position to witness the murder. Without him, no one would have caught on to Saren's plans until it was too late]].