[[quoteright:350:[[VideoGame/FinalFantasyXI http://static.tvtropes.org/pmwiki/pub/images/ignorance_is_bliss_2891.jpg]]]]

->''There's ''always'' an Arquillian Battle Cruiser, or a Corillian Death Ray, or an intergalactic plague that is about to wipe out all life on this miserable little planet, and the only way these people can get on with their happy lives is that they DO! NOT! KNOW ABOUT IT!''
-->-- '''Agent Kay''', ''Film/MenInBlack''

So, the hero has found the giant factory belonging to the BigBad. He enters with his TrueCompanions and finds weapons that could kill thousands or maybe even millions, all built by and being built by the locals. While the hero believes that the locals all knew about the Big Bad's plan and were helping him willingly, a few questions from TheHeart clears up the matter -- the locals simply think the weapons are harmless machinery that will be used for building houses and/or farming.

This trope describes situations where somebody uses someone to make or do something by lying about what exactly it is that they're doing, or assuring them that it's for the greater good. It could be something as simple as stealing plans or moving an item to another location, or something major, like building a DoomsdayDevice or breaching a boundary -- if the BigBad plays on their ignorance to make them do something; it's this. This can often result in a HeelFaceTurn or MyGodWhatHaveIDone. See also EvilPlan, NiceJobBreakingItHero, AwfulTruth, RedemptionEqualsDeath and AmbiguousInnocence.

Not to be confused with WhileRomeBurns, when everything is going horribly wrong but everyone responds to it with denial.

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!!Examples:

[[foldercontrol]]

[[folder: Anime And Manga]]
* In ''Manga/BlackButler'', Ciel tells Snake that his missing friends' whereabouts were unknown and that staying with Ciel is the fastest way to see them again. [[spoiler: The reader knows that they were all killed by Ciel's staff when they attempted to ambush the mansion.]]
[[/folder]]

[[folder: Film]]
* ''Film/DiamondsAreForever'': Blofeld kidnaps Willard Whyte and uses his industrial empire to build and launch a Kill Sat. Only one other person in Whyte's organization knows what's going on: the rest are kept ignorant.
** Also in ''Film/DiamondsAreForever'', we have a rocket scientist who helped Blofeld to build the Kill Sat because he thought Blofeld would use it to help achieve world peace. Of course, this wasn't the case.
* At the start of ''Film/VanHelsing'', Dracula tells Dr. Frankenstein that he did this to him.
* Cypher in ''Film/TheMatrix'' decides to betray Morpheus to the Agents. "Ignorance is bliss" is what he uses to justify it when he meets with Agent Smith:
-->'''Agent Smith''': ''[He and Cypher are eating at a fancy restaurant]'' Do we have a deal, Mr. Reagan?
-->'''Cypher''': ''[cuts a piece of steak and holds it in front of him]'' You know, I know this steak doesn't exist. I know that when I put it in my mouth, the Matrix is telling my brain that it is juicy and delicious. After nine years, you know what I realize? ''[Eats the piece of steak and sighs contently]'' Ignorance is ''bliss''.
-->'''Agent Smith''': Then we have a deal?
--> '''Cypher''': I don't wanna remember nothing. ''Nothing'', you understand? And I want to be rich. You know, someone important like an actor.
-->'''Agent Smith''': Whatever you want, Mr. Reagan.
-->'''Cypher''': Okay. I get my body back into a power plant, re-insert me into the Matrix, I'll get you what you want.
-->'''Agent Smith''': Access codes to the Zion mainframe.
-->'''Cypher''': No, I told you, I don't know them. I can get you the man who does.
-->'''Agent Smith''': Morpheus.
* This, combined with the fact that TheWorldIsAlwaysDoomed, is why the ''Film/MenInBlack'' go to such lengths to keep up TheMasquerade.
* Used in ''Film/CabinFever'' when the busty brunette [[CoitusEnsues suddenly offers herself to the lone surviving hero.]] She has the killer [[AntagonistTitle fever]], though she isn't showing any signs yet. Midway through sex, the guy tells her he's worried that they aren't using a condom. So the woman assures him that she's perfectly healthy, because by that point, the only think that telling the truth could do is spoil their fun.
* In ''Film/CafeSetareh'', Ebi feels that Fariba and her mother would be better off not knowing that [[spoiler: Khosro is dead]], so he burns all the newspapers that would tell them.
[[/folder]]

[[folder: Literature]]
* In ''Literature/AmericanGods'' [[spoiler:Wednesday uses Shadow to start a war between the gods so they can conquer the new gods, when in reality, Wednesday and Loki just want the power they'll gain from a field of dead gods]].
* ''Literature/TheBelgariad'': Errand is brought up to be totally innocent so he can sneak into the Rivan throne room to steal the Orb, without knowing what will happen afterwards.
* In the ''StarWarsExpandedUniverse'' the person responsible for designing the Death Star and [[JediAcademyTrilogy Sun Crusher]] has no idea that they'd be used to destroy habitated planets and suns around which [[BuffySpeak habitated star sytems were being habitated in]], intending for them to be mining vehicles.
* Harry Harrison's ''Literature/TheStainlessSteelRat''. Jim diGriz discovers that the government of the planet Cittanuvo is building a Warlord class battleship under the pretense that it's just a transport ship. After investigating, he finds out that two elite criminals tricked the government into building the ship with the intent of stealing it and using it for interstellar piracy.
* The Howlers in ''Literature/{{Animorphs}}'' routinely wipe out entire species at their master's command so the protagonists assume they must be consumed with rage and enjoy causing destruction. It turns out they think it's all a game.
* In George Orwell's classic dystopia ''Literature/NineteenEightyFour'', the last of three core slogans that the Party propagates to the citizens of Oceania is "Ignorance Is Strength". (The other two being "War Is Peace" and "Freedom Is Slavery")
* ''Literature/EndersGame'', because [[spoiler: when he goes to the simulator he's actually commanding real troops.]]
* In ''Literature/{{Pact}}'', ignorance keeps the vast majority of humans safe from the supernatural by maintaining the {{Masquerade}}. As almost all supernatural creatures have been forced over the centuries to swear to abide by the Standard of Solomon, which prevents them from attacking the innocent without cause, this has allowed humanity to expand to its current levels of population, to the point that they reproduce faster than the Others can kill them, Others are steadily being driven from their hiding places by ignorant humans against whom they can't fight back, and those few that ''can'' are dealt with by the few humans that know the truth.
[[/folder]]

[[folder: Live Action Television]]
* In ''Series/{{Glee}}'', Sue gets Brittany to give her the set list for New Directions, but Brittany has no clue about what she's going to do with it.
* ''Series/{{NCIS}}'': In 6.21, "Toxic", Abby builds a biological weapon without knowing what it is.
* In ''Series/{{Dollhouse}}'', [[spoiler: it turns out the Evil Corporation is building a Doomsday Device by making each of their research departments around the world build a little part of it, and nobody knowing about the larger picture]].
* ''Series/{{House}}'' had an episode called "Ignorance Is Bliss" where it turned out that [[spoiler:the Patient of the Week (who was a genius) was regularly taking cough medicine so he would be around the same intelligence level as his girlfriend]].
* The Dark Curse in ''Series/OnceUponATime'' exiled characters from a fairy tale world into the real world with new memories. Considering nearly all of them have ridiculously tragic back stories, sometimes now knowing is a blessing.
[[/folder]]

[[folder: Music]]
* "The Wingmen" by ''Creator/DosGringos'' contains the line:
-> We're the wingmen and there's no better life than this,
-> For knowledge is the power, but ignorance is bliss
[[/folder]]

[[folder: Video Games]]
* ''VideoGame/SpyroYearOfTheDragon'': Bianca helps the Sorceress abduct the dragon eggs thinking they'll be raised in the Forgotten Worlds- the Sorceress really plans to kill the dragons and take their wings for a spell.
* In ''VideoGame/MetalGearSolid'', Otacon designed Metal Gear REX under the assumption that it would be used as a mobile TMD to destroy incoming missiles - he had no idea that his employers would arm it with nukes instead.
* This is probably the one and only PetTheDog moment from [[spoiler: Matt Engarde]] in ''VisualNovel/PhoenixWrightAceAttorney'':
--> '''[[spoiler: Engarde]]''': (Sigh)... I thought if you didn't know, maybe you wouldn't feel so bad for doing your job...
* In ''AliceMadnessReturns'', the loading screen may give this piece of advice: "Ignorance is bliss, except when it's fatal."
* The motivation behind [[spoiler:Ryoji asking you to kill him]] in ''VideoGame/{{Persona 3}}''. Nyx is coming to destroy the world, and it's generally believed that there's no way to stop it. [[spoiler:Killing Ryoji]] will eliminate [[TheHiddenHour the Dark Hour]] and erase any associated memories, leaving the world to live out what's left of its life in peace.
** Played in a ''far'' darker variant in ''VideoGame/ShinMegamiTenseiIV''. [[spoiler:The Archangels' idea of a peaceful, harmonious Mikado is one where literacy, education, and worship or even mere admiration of anyone besides God doesn't exist. You help achieve this in the Law ending.]]
* Referenced in ''VideoGame/PlanescapeTorment'', when Morte tells a story about a man who suddenly finds himself in an alley facing a genie, who asks him for his third wish. The man asks what's going on, and the genie says that he's allowed to ask for three wishes, and his second wish was to undo his first wish. After thinking for a moment, the man wishes to know himself, the genie grants it, and just before disappearing, says "Funny, that was your ''first'' wish."
* ''VideoGame/{{RuneScape}}'' has this in the quests "Priest in Peril" and "Devious Minds".
* In ''VideoGame/WorldOfWarcraft'' Horde-players visiting Dragonblight are offered a questline to help the Forsaken gather ingredients for a plague that will inevitably wipe out the scourge, [[spoiler: which Puttress later uses to kill, not only scourge-soldiers, but also the combined army of humans and orcs battling them]].
* In ''VideoGame/StarControl2'', the Arilou hinted of a malicious presence from [[EldritchLocation Beyond]], but refused to elaborate further when asked, claiming that ignorance is the best protection against them, as they can not see mankind unless mankind show themselves.
[[/folder]]

[[folder: Webcomics]]
* Fighter of ''WebComic/EightBitTheater'' is an example of this. The other Light Warriors often get him to do things by convincing him it is for the greater good. There's also the fact that he still believes they're heroes after all the untold damage they've caused.
* ''Webcomic/TheInexplicableAdventuresOfBob:'' In an uncharacteristically manipulative moment, in her second appearance, Voluptua lets Bob fly off on what he thinks is a very simple mission, while she suspects an alien supercriminal [[http://bobadventures.comicgenesis.com/d/20061202.html ''just might'']] be waiting for him.
* In ''Webcomic/BobAndGeorge'', [[http://www.bobandgeorge.com/archives/001226c until George explains the danger, Megaman is not worried.]]
[[/folder]]

[[folder: Web Original]]
* [[TheNarrator Cecil]] of ''Podcast/WelcomeToNightVale'' cheerfully reports the obviously bogus coverup stories concocted by the City Council with little to no indication that he doesn't believe every word. Also, choosing not to question what one is told seems to be the only way to survive living in Night Vale.
--> "Ignorance may not actually be bliss, but it certainly is less work."
* In his vlogs for ''WesternAnimation/AvatarTheLastAirbender'', Creator/DougWalker defended this trope as, sometimes, if you want to keep surviving and feeling sane, then you have to force yourself to stay in the dark about stuff.
* [[https://www.youtube.com/watch?v=TrlKC60jjSg Haven't you heard? A picture's worth a thousand words.]]
[[/folder]]

[[folder: Western Animation]]
* ''WesternAnimation/GravityFalls'' gives us the Society Of The Blind Eye, who believe in this and enforce it with LaserGuidedAmnesia.
[[/folder]]
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