%% taken from www.http://viktorhertz.com/
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[[caption-width-right:350:They also show you the best lines.]]

->''"Oh, yeah, I'm sure he's really gone. That's why the advertisements show him in about TWENTY more scenes that he wasn't in yet."''
-->-- '''WebVideo/TheNostalgiaCritic''''s review of ''Film/PearlHarbor''.

Movie {{trailers}} are [[NeverTrustATrailer known to mislead]], but sometimes they go in the opposite direction, giving away key plot points and twists (and sometimes what would have been a [[TwistEnding twist ending]]). The odds of this happening increase for the commercials aired after a movie's opening weekend.

Of course, some of this depends on your definition of "{{spoiler}}". Given that a trailer consists mostly of clips from the movie itself, a fair bit of spoilerage, in this case footage from a later part in the movie, is often inevitable.

There is also the matter of ''context''. An action movie, for example, may preview a random fight scene between two characters, but when you actually see the movie itself and realize that the other dude the hero was fighting happened to be his best friend in the beginning (which may or not have also been part of that trailer), you realize ''in retrospect'' that the trailer's fight scene was actually a {{foreshadowing}} or ChekhovsGun about the betrayal that occurs later.

When a certain event is a [[ForegoneConclusion foregone conclusion]], like with TheFilmOfTheBook or films BasedOnATrueStory, it's again debatable that it's really a spoiler. So if you read the examples below from a movie you haven't seen (either you have no intention of seeing it, or maybe you should reconsider continuing past this part), and find yourself thinking "I didn't even know that ''was'' a spoiler", don't worry about it.

It should also be noted that in many cases, commercials released after a film's first week or so will contain a lot more spoilers than those leading up to the premiere.

A related phenomenon can occur with DVD menu intro screens, which often include clips or montages of footage from the movie/episodes, thus potentially revealing them to the viewer out of context, before they have a chance to actually start playing the film proper. Often these will give away major plot points before the viewer has a chance to even start the film. These can be even more effective at spoiling the film's plot than trailers, since a viewer might plausibly be expected to go days between seeing a trailer and finally seeing the related movie, which might give them a chance to forget things from the trailer. With menu intro screens, on the other hand, the viewer is being shown clips from something that they are moments away from watching.

Also related are the trailers which run immediately previous to the show you have already sat down to watch. Known as a {{Precap}} and often starting with "Next, on X:", these segments spoil you on things you would just know in the next 30-60 minutes ''on a show you have already decided to watch''. These are intended to pull in the new viewer, but can seem unfair to those already into a show as you are most likely to be already watching at the beginning of the episode.

Can lead to TrailerJokeDecay. See also SpoilerOpening and LateArrivalSpoiler. Compare TheNamesake, when the title itself may be a spoiler. Or just see SpoilerTitle. See SpoiledByTheMerchandise for when plot points are spoiled by TheMerch. When the movie or TV series gets a home release, it may be lumbered with a SpoilerCover.

!! As this trope concerns spoilers, unmarked spoilers follow.
----
!!Examples:
[[index]]
* TrailersAlwaysSpoil/AnimeAndManga
* [[TrailersAlwaysSpoil/LiveActionFilms Film - Live Action]]
* TrailersAlwaysSpoil/{{Literature}}
* TrailersAlwaysSpoil/LiveActionTV
* TrailersAlwaysSpoil/VideoGames
* TrailersAlwaysSpoil/WesternAnimation
[[/index]]

[[foldercontrol]]

[[folder: Comic Books]]
* ''ComicBook/TheCloneSaga'': Marvel announced several months in advance that the Spider-Clone would return with interviews in Wizard magazine and advertisements. During this time, the titles saw a "mysterious drifter" covered in shadows spying on Peter and visiting the graves of Parker's parents. It was obvious that it was the clone but the titles still treated it as some sort of huge mystery even to the point where, when they revealed the clone's face, it was played off as some surprise twist.
* Marvel tried to keep the plot of the infamous ''ComicBook/OneMoreDay'' under wraps, but an interview with J.Michael Strazynski revealed exactly what would happen, who would be involved, and what the outcome would be. Despite this Marvel ran a promotional campaign for the story which gave readers a multitude of options as to who could help Spider-Man in his darkest hour, but thanks to the JMS interview, everyone knew it was Mephisto, they also knew the outcome resulted in the retconning of the Spider-Marraige in the 616 continuity.
* When Marvel announced that ComicBook/{{X 23}} would be joining the cast of ''ComicBook/AllNewXMen'', they effectively spoiled that she'd survive the events of the then-still running ''ComicBook/AvengersArena'' series, ruining the supposed AnyoneCanDie element. The writer of ''Arena'' even jokingly acknowledged this at New York Comic-Con.[[http://www.newsarama.com/19176-nycc-2013-marvel-amazing-x-men-the-marvel-universe-live.html]]
** If you can believe it, ''the same convention'' also spoiled that Deathlocket, Hazmat, Anachronism, Cammi, and Cullen Bloodstone would survive when Marvel announced the SpiritualSuccessor, ''Avengers Undercover''.
* In 2011 MarvelComics was especially bad about this, saying that now they'll probably kill off a major character every quarter to raise sales:
** February saw the death of The Human Torch in the conclusion of the "Three" arc in ''Comicbook/FantasticFour'', the title of which heavily implied one of the titular four dying. While the story's title managed to avert the typical OhAndXDies nature of a lot of "The Death of X" stories Marvel ruined any potential surprise by spoiling it to the press the day before the release.
** Early June saw the death of ComicBook/BuckyBarnes, the second Captain America, in ''ComicBook/FearItself'' #3 to the surprise of almost nobody as Marvel had already announced that original ComicBook/CaptainAmerica Steve Rogers would return to the uniform a month later (due to [[Film/CaptainAmericaTheFirstAvenger the movie]]). The only reason it didn't make any sort of media splash was because Creator/DCComics one upped them the day before by announcing their [[ComicBook/{{New 52}} reboot]].
* ''ComicBook/SecretWars2015'' was marketed on the premise that the MarvelUniverse was being KilledOffForReal, and that nobody was sure what new universe would be taking it's place. The subsequent sneak peeks for books like ''All-New, All-Different Avengers'' and ''Invincible Iron Man'', coupled with WordOfGod confirmation that books like ''ComicBook/MsMarvel2014'' would continue, more or less confirmed that the "new" Marvel Universe was essentially the same one as the old one.
** This was solidified when Marvel released its new line-up of post-''Secret Wars'' books, which spoiled a number of plot points about the ending, such as the Marvel Universe being restored, and characters like ComicBook/OldManLogan joining the mainstream continuity.
* In 2013, DC Comics spoiled the death of Damian Wayne, [[AffirmativeActionLegacy the most recent]] ComicBook/{{Robin}}, days before it actually occurred in ''[[ComicBook/GrantMorrisonsBatman Batman Incorporated]]''. This of course gave media outlets ample time to cover the story.
* After initially teasing it as one of the big mysteries of the [[Comicbook/MarvelNOW All-New Marvel NOW!]] launch, Marvel informed the New York Times that the new ComicBook/MsMarvel would be a Muslim teenager named [[Comicbook/MsMarvel2014 Kamala Khan]].
** They did the same thing with [[Comicbook/UltimateSpiderMan Miles Morales]]' identity, which was revealed to mainstream news outlets before the book had even hit stands. The ensuing controversy over a black Spider-Man was covered on everything ranging from Fox News to TheDailyShow.
* In yet ''another'' Marvel example, a released script for ''Comicbook/MightyAvengers'' spoiled that the new Ronin was Comicbook/{{Blade}} a full ''eight months'' before the writer's intended reveal date.
* A few weeks before ''ComicBook/ForeverEvil'' kicked off, DC announced that ''Trinity War'' would see the Crime Syndicate of Earth 3 removing the Justice Leagues from the picture & taking over the Earth, with ComicBook/LexLuthor's alliance of villains fighting back.
* Marvel basically confirmed that ''Hunger'' would end with a FailureIsTheOnlyOption scenario by revealing that their next CrisisCrossover for the [[UltimateMarvel Ultimate]] line, ''[[Comicbook/CataclysmTheUltimatesLastStand Cataclysm]]'', would see ComicBook/{{Galactus}} reaching Earth and beginning his assault. To those unaware, the entire premise of ''Hunger'' was that ComicBook/SilverSurfer and Rick Jones were desperately trying to stop Galactus ''before'' he could get to Earth.
* A plot point in ''Comicbook/OriginalSin'' involved ComicBook/NickFury recruiting Comicbook/BlackPanther, the [[ComicBook/BuckyBarnes Winter Soldier]], Gamora, ComicBook/DoctorStrange, Comicbook/EmmaFrost, [[ComicBook/AntMan Scott Lang]], and Comicbook/ThePunisher for a mysterious purpose. Eventually, it was revealed that Fury was dying of old age, and needed one of them to be his successor. Marvel treated the news as TheReveal and made it seem like a serious "Who will Fury choose?!" {{Cliffhanger}}, despite the fact that they'd ''already revealed'' that Fury's successor would be the Winter Soldier several weeks earlier.
* The same basic thing happened in Rick Remender's ''ComicBook/CaptainAmerica'' run. Marvel revealed on ''TheColbertReport'' that [[ComicBook/TheFalcon Sam Wilson]] would be the [[LegacyCharacter new]] Captain America, yet still treated it like a big secret in-story, and even tried to make it seem like Sam had died pulling a HeroicSacrifice just before he emerged as the new Cap.
** This was then {{Lampshaded}} when Sam was finally unveiled onscreen to his Avengers teammates. He immediately says that there is no drama in this reveal, and that [[LeaningOnTheFourthWall everyone]] ''must'' have known by now that he was going to be the new Cap.
* TheReveal of ''Comicbook/DCRebirth'' #1 is that the Pre-''Comicbook/{{Flashpoint}}'' [[Comicbook/TheFlash Wally West]] still exists and remembers the previous continuity. Naturally, DC revealed this in official previews and sanctioned reviews about a week before the issue hit stands.
* ''Comicbook/{{The Vision|2015}}'' established a pretty effective AnyoneCanDie tone, since Vision's wife and kids are all new characters without any ties to the rest of the Marvel Universe. Marvel spoiled that [[spoiler: his daughter, Viv]] would survive the book when [[spoiler: she]] was confirmed to be part of the new ''Champions'' series.
[[/folder]]

[[folder: Fan Fiction ]]
* The summary of ThirtyHs is basically a summary of the events of the first few chapters.
* Website/FanFictionDotNet put a massive ''Film/TronLegacy'' spoiler in their "filter by character" view. This was ''before'' the film hit DVD.
* In the fic [[http://www.fimfiction.net/story/71340/mvp MVP]], the accompanying image outright spoils its punchline (the identity of a character).
* In the ''WesternAnimation/TotalDrama'' story, ''[[Fanfic/LegacyTotalDrama Legacy]]'', the brief Introduction suggests pretty strongly that the story's "{{for want of a nail}}" premise will end badly for a certain character. Sure enough, it does.
[[/folder]]

[[folder: Film - Animated]]
* ''WesternAnimation/{{Megamind}}'' probably had one of the worst offending trailers, in which it revealed that Metro Man was ''not'' dead and had simply given up superheroing. The entire film revolved around the fact that Megamind was trying to cope with having killed Metro Man.
* In ''WesternAnimation/{{Shrek}} 2'', the nature of Puss N Boots (a cute little kitty who just happens to be a mercenary) is clearly meant to be a comedic twist, but the trailers practically made it the main selling point. ''Shrek the Third'''s merchandise spoiled the birth of the Shreklings (Shrek and Fiona's children) and the dragon/donkey hybrids (Donkey and Dragon's children), as well as the DistressedDamsel [[EverythingsBetterWithPrincesses princesses]] going ActionGirl.
** TV spots also showed Donkey as a white stallion, though they didn't show Shrek in his human form.
* ''WesternAnimation/{{Coraline}}''. The trailer shows the scene where the Other Mother gives Coraline the buttons and sewing needles.
* The trailer for ''WesternAnimation/{{Up}}'' spoiled that Charles Muntz is the villain.
** Most trailers for ''Up'' were actually a remarkable aversion to this trope. Other than the presence of a talking dog and a floating balloon house, nothing else was really shown.
* In ''WesternAnimation/{{Paranorman}}'' the trailer spoils nearly every joke, even if it does not spoil the plot for the most part.
** Even worse, the Japanese trailer did spoil the plot.
* ''Disney/MeetTheRobinsons'' had a trailer that showed the future Lewis in a group with the Robinson family, with his arm around Franny from one of the final scenes in the movie, making the big reveal completely predictable.
* The ''original'' trailer for ''Disney/LadyAndTheTramp'', all the way back in 1955, shows us that not only do Lady and Tramp get together, but have puppies to boot.
* A home video trailer for ''WesternAnimation/TitanAE'' showed the entire movie, start to finish, in order, including the final scenes of a new Earth being formed and the lead characters on it. Why bother to see the movie?
* ''WesternAnimation/ChickenRun'': As shown in one of the TV commercials, the chickens manage to escape by making their own pedal powered plane!
* The trailer for Creator/DonBluth's ''WesternAnimation/{{Anastasia}}'' spoils the fact that Anya ''is'' Anastasia, and then shows her in the palace, in formal attire, being addressed as "the princess" and "Your Highness." The previous spoiler isn't so bad, since it's to be expected, but did they have to show she's recognized as such?
** The trailer for ''WesternAnimation/BartokTheMagnificent'' spoils Ludmilla's transformation into a dragon.
* ''WesternAnimation/ToyStory3'' had trailers that spoiled that the new toys were the villains. And while they never explicitly stated who the BigBad was, many viewers were able to tell just from what was shown (and if not that, then from the other marketing). In the later trailers it almost revealed that the real plot was an [[MoodWhiplash emotional rollercoaster.]]
** The [[http://www.youtube.com/watch?v=elI5BD5mgVk Japanese trailer]] was even worse about this, as is showed pretty much every main plot point.
* ''Disney/TheLionKing'''s trailer spoils most of the plot. Movie posters show Mufasa's ghost as well.
* ''WesternAnimation/HowToTrainYourDragon2''[='=]s trailer takes no issue with spoiling TheReveal of Hiccup's mother.
* The trailers for the sequel to ''WesternAnimation/{{Hoodwinked}}'' stress the fact that Red and co. are trying to save two innocent kids from a wicked witch. Save for the one which shows said "innocent" children with [[SlasherSmile creepy]] [[NightmareFuel grins]] saying: "[[EnfantTerrible You've]] [[CreepyChild been hoodwinked!]] [[TitleDrop Too!]]"
* Watch ANY of the commercials for ''WesternAnimation/ThePowerpuffGirls Movie'' and you've watched the whole thing (and this could've been why the movie didn't do so well). It also doesn't help that Cartoon Network aired these commercials on practically every commercial break when the movie came out.
* A TV spot for ''WallaceAndGromit'': ''WesternAnimation/TheCurseOfTheWereRabbit'' spoiled that the were-rabbit is Wallace, showing fuzzy fur popping out of his trademark sweater-vest. It even had the announcer say "What started as a little mistake became a ''big'' problem" over scenes of the mind-manipulator accident and said transformation scene.
* [[http://www.youtube.com/watch?v=Pv7l2QMyaXE This official preview]] for ''WesternAnimation/MonstersUniversity'' spoils the entire plot.
* The toy commercials for the ''Toys/{{Bionicle}}'''s Glatorian Legends line of figures showed glimpses of the then-upcoming movie, ''The Legend Reborn''. Among them, the very shot of the four heroes unleashing the final blast at the Skrall and Bone Hunter army, from the end of the climax! Website promos also spoiled Metus' transformation into a snake, thereby revealing that he was to be the traitor. This was also spoiled by the site's behind-the-scenes videos, which showed the actors recording lines -- fans have narrowed the identity of the traitor down to Berix and Metus, and then the clips showed Berix's VA talking to the traitor...
* ''WesternAnimation/KungFuPanda'':
** The DVD trailer for ''WesternAnimation/KungFuPanda2'' completely spoiled the fact that Po's biological father, and several other pandas, are still alive, which wasn't revealed until the last few seconds of the film.
** The DVD trailer for ''WesternAnimation/KungFuPanda3'' spoils literally almost the entire movie, including Kai's destruction of the Jade Palace, Po training of the panda village to fight against Kai, and the final battle in the Spirit Realm.
* The trailer for Life's a Jungle: Africa's Most Wanted clearly shows the ending of the movie.
* A fan-edited trailer for ''Disney/{{Frozen}}'' parodies this. The video makes some {{Retraux}} attempts at emulating an ad from TheNineties, with a love ballad playing in the background, some idents from Disney's VHS tapes serving as bookends, and a clip revealing some major points about the climax (the scene in which a freezing Anna tries to stop Hans from killing Elsa) appearing before the title card.
** Official trailers show some spoileriffic clips, such as Elsa bringing back summer and saving Olaf from melting. A more subtle example is Elsa giving Anna a hug, when Elsa had previously been too scared to approach, much less touch, Anna. It's also apparent on closer examination that this happens after Anna's aforementioned HeroicSacrifice frees herself from the curse.
* One preview of ''WesternAnimation/TheLegoMovie'' showed bits from Emmet's vision, including a live-acted human hand. Also, Bad Cop's fate was revealed by his toy, released prior to the movie. The LEGO sets actually gave away many details, such as Bad Cop's parents getting frozen in glue or Uni-Kitty disguising herself as Business-Kitty, but not always the exact interpretation of the scenes.
* This ''Disney/{{Mulan}}'' [[https://www.youtube.com/watch?v=wAbGAkkOgcM trailer]] in which it shows the Emperor's big speech at the end, which in turn gives away big chunks of the movie. It even shows the scene with her turning around and all of China bowing to her.
* The TV commercials for ''WesternAnimation/{{Nine}}'' try their best to hide things by cutting rapidly from scene to scene, but they still manage to spoil 2's funeral, the destruction of the Fabrication Machine, the Cat Beast's death, and several of the dolls having their souls sucked out by the talisman. Geeze!
* The original BMG Video trailer for ''[[WesternAnimation/MagicAdventuresOfMumfie Mumfie's Quest]]'' shows Mr. and Mrs. Admiral being reunited, Whale being freed from a net by the electric eels and part of the scene where Secretary of Night gets turned into stone by the Cloak of Dreams.
* The trailers for ''WesternAnimation/TheThiefAndTheCobbler'' had clearly shown the entire plot of the film which included the three golden balls being stolen from the kingdom, the climatic battle with the main villain One-Eye and Tak and Princess Yum-Yum getting married at the end of the film.
* Near the end of the second trailer for ''WesternAnimation/TheBookOfLife'', it happens in a brief second but one can see the Sanchez ancestors near the climax.
* A French trailer for ''WesternAnimation/SongOfTheSea'' spoils the plot from beginning to end, even going as far as to include the last shot of the film.
* The UK advertising for ''Disney/BigHero6'' reveals that Hiro wants to kill Yokai.
* The trailers for ''WesternAnimation/StrangeMagic'': The scene where Roland makes out with some kind of insect is frequently shown in trailers.
* The trailer for ''WesternAnimation/AnAmericanTail Fievel Goes West'' didn't spoil itself so much, but the fact that the trailer of the sequel movie was included at the beginning of every VHS release of the first movie after 1991 meant that it revealed the ending of the movie before it even started (beginning with Fievel riding a pigeon with his sister and asking if he could see more of America, spoiling that he finds his family).
* As far as ''WesternAnimation/InsideOut'' goes, whatever you do, if you don't want to be spoiled, ''stay away from the Japanese trailers!''
** Some of the American trailers spoil the movie as well. Two notable examples were the clip where Joy rides in Bing Bong's rocket to the top and we can clearly see that he is not in it, and the scene where Joy and Sadness return to Headquarters.
* One of the trailers for ''WesternAnimation/TheSpongeBobMovieSpongeOutOfWater'' clearly shows Plankton as Plank-Ton.
* ''WesternAnimation/FindingDory'' had a bad case of this:
** Later trailers and commercials for the film spoil the scene where Hank gets poked by a kid and inks in the touch pond, causing the kids in the area to run away. It got to the point where said clip was shown during shows where Ed O'Neil, Hank's voice actor, was interviewed such ''Entertainment Tonight''.
** [[https://m.youtube.com/watch?v=ByqIiRUuoQ0 The clip used to introduce Hank]] in this April Fool's prank is part of the scene where Dory reaches her old home at the Open Ocean exhibit.
** [[https://www.ispot.tv/ad/AS8q/subway-finding-dory-peek-into-dorys-world This Subway commercial for kids' meals based off the film]] uses clips that spoil some major plotlines in the movie, including the fact that Marlin and Nemo wait for Dory in the tanks that are going on the truck to Cleveland.
** [[https://www.youtube.com/watch?v=bnTHJM7ct88 The film's Japanese trailer]] shows the otters bringing Dory into the truck bound for Cleveland as well as Destiny jumping out of her enclosure, both from the climax of the film.
** [[https://www.youtube.com/watch?v=wJo-a9lI_us This commercial]] is comprised of clips from the climax from the film.
* Oh boy, where to start. Most of the trailers for ''WesternAnimation/TheGoodDinosaur'' spoil Poppa's death, Arlo's friendship to Spot, the meeting of Forrest Woodbush, Arlo helping the cowboy T-Rexes, Arlo encounters the main villian, Thunderclap and also the climax. In short, the trailers just showed you the entire movie.
* A ''WesternAnimation/SausageParty'' trailer spoils Carl's death.
[[/folder]]

[[folder:Web Animation]]
* Parodied in ''WebAnimation/TheDementedCartoonMovie'', which opens with a mock trailer that does the exact opposite: it doesn't reveal ''anything'' about the movie it's advertising because it's heavily censored, and parts of it have been replaced with stuff like [Dialogue Missing] and [Title Missing].
* In ''WebAnimation/{{RWBY}}'''s Black trailer, which serves as an introduction to the character Blake Belladonna, the background music is "From Shadows", a song with lyrics about people suffering FantasticRacism from humans and planning their revenge. One of the plot points in the series involves the [[LittleBitBeastly Faunus race]] being subjected to prejudice by humans (the lyrics in the trailer include "treated like a worthless animal", to make it clear the song is about them). This ends up spoiling, or at least strongly hinting at the fact that Blake is actually a Faunus disguised as a human, which is a twist revealed in the second-to-last episode of Volume 1.
[[/folder]]

[[folder:Web Comics]]
* Parodied with the second trailer for ''TheWayOfTheMetagamer 2: InNameOnly'', which intentionally reveals many, many plot twists.
* The trailer for the ''Webcomic/{{Homestuck}}'' video game kickstarter was aimed entirely at people who had already read the comic, so it contained spoilers for ALL the major updates as of the time it was made. At least the spoilers were flashing by so fast that new readers missed half of them and didn't know enough to recognize many of the others as spoilery.
* ''WebComic/Persona4TWAddOn'' lampshades the fact that the big plot 'twist' was given away on the cover:
-->'''Shadow Labrys:''' Labrys is a robot? Heavens to murgatroyd. What a complete and utter surprise...or it mighta been if it hadn't been given away on the ***ing box art...
[[/folder]]

[[folder: Web Original]]
* The trailer for Website/ThatGuyWithTheGlasses' two-year anniversary special ''WebVideo/{{Kickassia}}'' had [[WebVideo/TheSpoonyExperiment Spoony]] shouting "Oh my gosh! It's 3D Lee!"
** And the final trailer for their fourth anniversary special ''WebVideo/ToBoldlyFlee'' spoiled WebVideo/TheNostalgiaCritic absorbing the PlotHole.
* More like "the preview always spoils", unless the [=YouTube=] user has found a way to muck with the video thumbnail of a movie, [=YouTube=] will default it to the middle of the movie. If it's say, for a race and the course is known, you can tell at least midway who's winning.
** A variation: if you're going to watch a comedy video, you'd do well to avoid looking at the top comments. They almost always contain the funniest jokes.
* Parodied by Website/CollegeHumor in the hypothetical "[[http://www.collegehumor.com/video/6471804/if-movie-trailers-ruined-endings If Movie Trailers Ruined Endings]]", where the trailer guy goes out of his way to spoil the endings and plot twists. Warning: spoilers for ''Film/FightClub'', ''Film/TheUsualSuspects'', and ''Film/ReservoirDogs''. Also includes references to LukeIAmYourFather and AllThereIsToKnowAboutTheCryingGame.
* After part one of the WebVideo/{{Tabletop}} episode in which the horror RPG ''Dread'' was played, a "next time" trailer manages to spoil every major plot development in part two, rather ruining the tension that had been built up in part one.
[[/folder]]
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