[[quoteright:334:https://static.tvtropes.org/pmwiki/pub/images/detention-la-locandina-del-film-235451_6916.jpg]]
[[caption-width-right:334:"''Mullet beats pony-tails."'']]

''Detention'' is a 2011 film[[note]]Though it was released in 2012, it was finished and making the festival circuit the prior year.[[/note]] by Joseph Kahn, maker of the {{Cult|Classic}} "[[SoBadItsGood Classic]]" ''Film/{{Torque}}''. A send-up of teen horror movies and teenage life in general, it follows a group of students at Grizzly Lake High School who must come to grips with a masked killer, dressed like the villain from the horror franchise ''[[ShowWithinAShow Cinderhella]]''. When the principal (played by Creator/DaneCook) suspects that one of them is the killer, he sends them all to Saturday detention in place of the prom.

And then things go completely crazy.

The main thrust of the film is that each of the main characters is the protagonist of a different teen movie. Riley Jones, the heroine, is a [[TheSnarkKnight Snark Knight]] in the mold of [[WesternAnimation/{{Daria}} Daria Morgendorffer]], [[Film/{{Juno}} Juno MacGuff]], or [[Series/MySoCalledLife Angela Chase]]; Clapton Davis, the male protagonist, is a Film/{{Ferris Bueller|sDayOff}}-esque HighSchoolHustler; the cheerleader Ione Foster has [[FreakyFridayFlip swapped bodies]] with [[FutureLoser her ex-cheerleader, stuck-in-the-'90s mother]] Sloan in a plot reminiscent of ''Literature/FreakyFriday''; Sander Sanderson is the heroic nerd who's trying to get the girl; the JerkJock Billy Nolan has insect-based superpowers that he possesses little control over, in the vein of [[ComicBook/SpiderMan Peter Parker]]; and finally, Elliot Fink is living in an apocalyptic time warp straight out of ''Film/DonnieDarko''. Together, with the help of [[MakesJustAsMuchSenseInContext a time-traveling bear mascot]], they must come together to not only save their own asses, but the entire world -- or at least, Grizzly Lake, because really, have any of these kids ever seen the world outside Grizzly Lake?

Not to be confused with th... well, actually, ''six'' other works of the same name: another, less comedic slasher movie made in 2010, a 2003 Creator/DolphLundgren action film about drug runners attacking a school, an [[WesternAnimation/{{Detention}} animated series]] from 1999-2000, [[VideoGame/{{Detention}} an indie Taiwanese horror game]], the 2019 film based on the video game and the 2020 series based on the video game.

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!!Tropes:
* AbhorrentAdmirer:
** Sander Sanderson makes unwanted advances towards Riley Jones on a regular basis. [[spoiler: Riley's rejection of him prompts him to attempt blowing up Grizzly Lake in the past. He also attempts to murder her for this reason after he fails to detonate Grizzly Lake.]]
** [[spoiler: Ione/Sloane is initially repulsed by Verge, and has to ask him out to the prom in order to prevent him from blowing up Grizzly Lake on Sander's behalf. When she gets to know him, he turns out to be a better person than she thought.]]
* AbusiveParents: [[spoiler: Billy Nolan's father is shown in flashbacks to be an alcoholic loser who treats Billy like crap, cares more about his TV set than about his own son, and forces Billy to wear the TV on his hand when he discovers that Billy's arm is mutated, saying that he wants nobody to know his son is a freak. When the TV finally comes off, it is implied that Billy's father is the first person that Billy lashes out against before becoming a full-fledged JerkJock.]]
* AlphaBitch:
** Taylor Fisher is a popular girl who believes herself to be better than anyone else, even going so far as to make a guide to not being a total reject. Fortunately, [[AndThereWasMuchRejoicing we only have to put up with her for five minutes]], as, naturally, she ends up slaughtered by someone in a Cinderhella mask, [[spoiler: namely, Sander Sanderson]].
** Sloan is implied to have been snobby and entitled in her youth, treating a young Karl Verge with disrespect when he expresses attraction towards her. Her daughter, Ione, is closer to a LovableAlphaBitch, though, as she is a much better friend to Riley [[spoiler: before switching bodies with her mother]].
* AnArmAndALeg: [[spoiler:Billy]] gets his arm hacked off by the killer.
* AsianAndNerdy: Toshiba, as his name would imply, is the tech savvy student of presumably Japanese descent, [[spoiler: who modified the school's bear mascot into a time machine]].
* BathroomStallOfOverheardInsults: After arriving at school, Riley is in a stall in the girls bathroom when she hears Ione talking to her friends and calling her a loser and asking where she gets off being interested in Clapton, who is Ione's boyfriend.
* BlackComedy: Only way to make casual jokes about a suicidal girl.
* BungledSuicide: Riley attempts to hang herself but slips off the chair before she is ready and starts slowly strangling herself. She is only saved when Cinderhella, attempting to kill her with an axe, [[NiceJobFixingItVillain winds up cutting her down instead]].
* BrickJoke: Riley's Canadian debate rival Gord and the [[spoiler:news reports about the UFO]] come together in the final scene.
* CarCushion: The killer throws the body of Taylor Fisher out of her bedroom window, where it crashes through the windscreen of her mother's car (with her mother still inside the car).
* ChildhoodFriends: Clapton Davis and Riley Jones live across from each other and have been friends for years. Then [[ChildhoodFriendRomance Riley developed a crush on Clapton, and he started dating Ione]]/Sloan.
* ChildhoodFriendRomance: [[spoiler: After they changed the fabric of space-time, Clapton and Riley see that Ione/Sloan is now dating Toby T, and they get crowned Prom King and Queen, implying that, in this timeline, they themselves have been together a while. [[DancePartyEnding Then they dance]].]]
* ClassicVillain: [[spoiler: Sander Sanderson is a remorseless murderer motivated by [[AbhorrentAdmirer lust]] towards Riley Jones, and [[GreenEyedMonster envy]] of the fact that she has a crush on Clapton Davis. While his VillainousCrush Riley is also lustful and envious regarding Clapton, she only tries to harm herself in response to her own envy, while Sander attacks other people around him when he doesn't get what he wants, including Riley. Furthermore, Riley puts her envy regarding Clapton's relationship with Ione Rose to rest when [[RedHerring she thinks that Clapton is the killer]]. Finally, while Riley is painfully aware of her shortcomings, Sander believes his actions are justified, and hastens to point out Riley's flaws.]]
* CourteousCanadian: Subverted with Gord, who makes Riley wish that the stereotype of the "polite Canadian" were true. [[spoiler:Then again, he's not a Canadian, but an evil alien.]]
* DancePartyEnding: [[spoiler: The prom scene with [[Music/{{Hanson}} MMMBop]] is a straight homage to the climax of ''Film/DirtyDancing''. It's not the actual ''ending'' here, though, as the killer still needs to be dealt with.]]
* DarkAndTroubledPast: During his high school years, Principal Verge was an outcast who was ready to blow up the school. Thanks to the TimeyWimeyBall being tampered with, somebody created an alternate timeline where he succeeds, leading to TheEndOfTheWorldAsWeKnowIt (actually just the destruction of Grizzly Lake, since that's the only world these kids have ever known).
* DawsonCasting: [[invoked]] Parodied in the ''Cinderhella 3'' scene, where the characters in that film watch a bootleg copy of ''Slashing Beauty 4'' (just as the characters in ''Detention'' are doing the same with a bootleg copy of ''Cinderhella 3''). All of the "teenage" cast members in ''Slashing Beauty 4'' are obviously middle-aged.
* DeanBitterman: Principal Karl Verge is a grouchy middle-aged man who hates his job, and wants Clapton to give him an excuse to graduate the latter; additionally, he makes 40 grand a year, plus dental, so he does not let Clapton have a Skittle. [[spoiler: In the new timeline where he ends up with Sloane, actually Ione in her mother's body, he ends up being much more [[PuttingThePalInPrincipal personable and likeable, not to mention cooler]].]]
* DecoyProtagonist: Taylor Fisher, who is basically a [[AlphaBitch more obnoxious]] [[AndThereWasMuchRejoicing version]] of [[Film/{{Scream}} Casey Becker]], is the first character to appear on screen, and if the audience didn't know better, they'd assume she was the main character. Naturally, because, you know, this is a slasher film, she only lasts five minutes.
* DeusAxMachina: Sander later grabs a fire axe [[spoiler:in order to attempt to kill Riley during their final confrontation, using it to decapitate Alexis when she walks in on him and Riley]].
* DeusExMachina: Extraterrestrial Ursus Ex Machina. The bear's [[CallBack magnetism powers]] end up saving the protagonists in the final confrontation.
* DiscOneFinalBoss: [[spoiler: It is initially suspected that Clapton Davis is the killer. Clapton is innocent; the real killer is Sander.]]
* DisappointedByTheMotive: [[spoiler: When Riley learns that Sander's motive for killing people amounts to not liking his fellow Grizzly Lake inhabitants, as well as being angry that Riley wouldn't put out, Riley is not amused.]]
-->[[spoiler: '''Riley''':]][[spoiler: You know, Sander, I used to think you were just a middle class chump with no game, but those pity points ran out!]]
* DisproportionateRetribution: [[spoiler: Sander thinks that Riley rejecting him, justifies his attempts at mass murder, as well as the murders he attempts to commit.]]
* DrivenToSuicide: Played for laughs in Riley's case, she tries to hang herself while complaining about the debate and Clapton.
* EnemyEatsYourLunch:
** [[HormoneAddledTeenager Sander Sanderson’s]] first moments on screen have him stealing [[BreadEggsMilkSquick a Coke, a Hersheys bar, and a urinal cake]], mistaking the latter for food before washing his mistake down with the aforementioned stolen Coke.
** {{Downplayed|Trope}} and {{Defied|Trope}} when [[TheSlacker Clapton Davis]] nonchalantly reaches for the Skittles in a jar on [[DeanBitterman Principal Karl Verge's]] desk after the latter chews him out for his bad grades. Verge refuses to allow his least favourite student to show what he sees as such blatant disrespect, so he grabs Clapton's hand, and denies the latter access to the candy jar.
-->'''Verge''': I make 40 G's a year plus dental. You may not have a Skittle.
* EntitledToHaveYou: [[spoiler: Sander's motive for attempting to blow up Grizzly Lake is more or less because Riley won't hook up with him. Sander seems to think that just because he was attracted to Riley before Clapton expressed any interest in her, she should have been with him.]]
* EvilIsHammy: [[spoiler: Sander loses his indoor voice, and throws a tantrum when it is revealed that he is the killer.]]
* EvilIsPetty: [[spoiler: According to Sander, the fact that the girl he has a crush on won't put out for him, and the fact that he simply doesn't like anyone else in Grizzly Lake, is a perfectly acceptable reason to blow up Grizzly Lake and murder his classmates.]]
* EvenEvilHasLovedOnes: [[spoiler: Gord turns out to be a plant based alien, who, during the alien invasion, says that his species is invading Grizzly Lake because they are upset at their vegetable kin being consumed by vegans.]]
* FishOutOfTemporalWater:
** When in Ione's body, Sloan doesn't seem to get that it's not 1992 anymore. Not only is her taste in music, movies, and fashion stuck in the early '90s, but she remarks that her and her classmates' generation experienced no great struggles or tragedies -- which may be true for a Gen-Xer like Sloan who grew up in the prosperous and peaceful '90s, but certainly not for a millennial like Ione, who would've grown up through UsefulNotes/TheWarOnTerror, Hurricane Katrina, and finally the Great Recession (which her classmates quickly point out).
** It also happens in the other direction to Ione in Sloan's 1992 body, what with her referring to the Top 40 music of that era as retro.
* {{Foreshadowing}}: Lots of it. Ione's definition of "stalker" points to [[spoiler: Sander]] as the killer, the newscasts about the UFO, Riley talking about [[spoiler: "the pervert who screwed the bear"]], and the trophy case at the beginning.
* FreakyFridayFlip: Ione and Sloan, with some temporal shenanigans thrown in. While Sloan awakens in her daughter Ione's body in the present day, Ione wakes up in Sloan's body... in 1992, back when Sloan was a teenager.
* FreudianExcuse: [[spoiler: Billy burned his hand a meterorite as a kid, his dog blew up (for... some reason), his father made him wear a TV on his hand for years to hide the mutation, and he was constantly bullied by his classmates until he was a teenager and the TV came off, at which point he became a total asshole.]]
* FunWithAcronyms: Taylor describes herself as having [[BitchAlert "Beauty, Intelligence, Talent, Charisma, and Hoobastank."]] (What? They're good.)
* FunnyBackgroundEvent:
** While the camera is focused on Elliot and Toshiba discussing [[spoiler:time-travel and whether the bear time machine works]], past them we can see Mimi inspecting [[spoiler:Gord's body [[ImpaledWithExtremePrejudice on the door]]]]. When [[spoiler:his bottom half [[HalfTheManHeUsedToBe gives way]]]], her reaction is priceless.
** Although it's eventually more obvious, most scenes with 1992!Ione have her whacking her cell phone, trying to get service.
* {{Goth}}: Mimi is a deadpan girl who wears dark clothing and likes grim things.
* GranolaGirl: Riley Jones, our protagonist, is a social justice and animal welfare minded vegan.
* GreenEyedMonster:
** Riley shows shades of envy towards Clapton and Ione. [[spoiler: Riley overcomes her envy when she thinks that Clapton is the killer. In any case, they end up together in the new timeline.]]
** [[spoiler: Sander, the killer, turns out to envy the fact that Riley likes Clapton, and not him.]]
* HateSink: [[spoiler: [[AbhorrentAdmirer Sander Sanderson]] is introduced making unwanted advances towards Riley Jones, a process he repeats on a regular basis. Overall, Sander reveals himself to be a petty douche who would murder a large number of people for [[PsychopathicManchild immature]] reasons.]]
* HalfTheManHeUsedToBe: [[spoiler:Principal Verge is cut in half by the killer in the original timeline.]]
* {{Hipster}}: Clapton stated that his music site will only make reviews of bands nobody ever heard about, and will dismiss anyone who said that they've already heard those.
* HormoneAddledTeenager: Sander Sanderson, Riley Jones' classmate, keeps making advances towards her. [[spoiler: Sander's motive for committing murder is the fact that [[EntitledToHaveYou Riley won't put out for him.]]]]
* HotForTeacher: Riley has a crush on her science teacher, Mr. Kendall. [[spoiler: Unfortunately (or fortunately) for Riley, Mr. Kendall is [[IncompatibleOrientation a gay married man]].]]
* HotTeacher: Mr. Kendall, the physics teacher, who gets a SexySoakedShirt scene when Clapton accidentally sets off the sprinklers, which makes it really hard for [[HotForTeacher Riley to keep her cool]].
* HypocriticalHumour: Sander riffs on everyone going to the mall when given a day off of school after a murder, when he is doing the exact same thing with Riley, Clapton, and Ione, and invites them to a costume party at his house to boot. [[spoiler: Sander's comments are much less humourous once you realize he is the killer]].
* IfICantHaveYou: [[spoiler: Sander decides to blow up Grizzly Lake, and later attempts to kill Riley, because he cannot handle being rejected by her.]]
* ImpaledWithExtremePrejudice: [[spoiler: Gord is run through with a ceiling fan and pinned to the door in the original timeline.]]
* IncompatibleOrientation: [[spoiler:Riley [[HotForTeacher has a crush]] on HotTeacher Mr. Kendall. Too bad for her, he is gay and his partner arrives to collect him just as she is attempting to put the moves on him.]]
* InstantHumiliationJustAddYouTube: The 6-second clip of Riley's boob gets over 20,000 views. She starts thinking of herself as a porn star.
* JerkJock: Billy Nolan is an overly macho, easily jealous football player who bullies Clapton Davis for dating the former's ex Ione,[[spoiler: actually Sloan in Ione's body]].
* LadyDrunk: Sloan is presented as an adult JadedWashout who drinks a lot.
* MeanwhileInTheFuture: The students in the present day are concerned about a bomb that's going to go off in nine minutes in 1992.
* MistakenForJunkie: Billy Nolan. He's not juicing, it's just his weird insect-like superpower.
* MistakenForPregnant: Principal Verge delivers a lecture to a girl about how there is nothing funny about TeenPregnancy. At the end, she says she's not pregnant. He then tells her to cut out the carbs.
* MisterSandmanSequence: Riley and Clapton's arrival in the 1992 high school, which features Music/HouseOfPain's "Jump Around" and has Riley getting called a corporate sellout for her expensive overalls.
* MyOwnGrampa: [[spoiler:"Ione is pregnant with herself?"]]
* NiceJobBreakingItHero: When Riley and Clapton [[spoiler:interrupt Sander's killing spree, they prevent Gord's death. Too bad Gord was an alien who was plotting to TakeOverTheWorld.]]
* NiceJobFixingItVillain: If not for Cinderhella interrupting Riley's suicide attempt, she likely would've strangled to death on her noose right there.
* NotWhatItLooksLike: Quoted word for word when Clapton walks in on Riley and Billy Nolan.
-->'''Riley''': This is the part where I say "It's not what it looks like".\\
'''Clapton''': This is the part where I say "How could you?".
* ObliviouslyEvil: [[spoiler: {{Downplayed|Trope}}. Sander believes that Riley rejecting him, and his hatred for Grizzly Lake, justify his attempts at mass murder and his successful murders of Taylor and Billy, as well as his multiple attempts at killing Riley. It never ONCE occurs to him that he is being disproportionately [[EvilIsPetty vindictive]].]]
* OffWithHisHead: [[spoiler: Sander decapitates Alexis when she walks in on him trying to kill Riley and Clapton, obliviously trying to coax him into having sex with her.]]
* OneWordTitle:
** The movie itself
** The fictional movie, ''Cinderhella''.
* ProgressiveEraMontage: Done in reverse with Elliot's time warp from the present day back to 1992, with all the fashions and music that appeared in between showing up.
* PsychoKnifeNut: Any time the killer doesn't use an axe, they use a knife. [[spoiler: Sander steals the cake knife at the dance, foreshadowing his role as the killer.]]
* PsychopathicManchild: [[spoiler: {{Downplayed|Trope}}. Sander, despite being around 18, throws a temper tantrum more appropriate for someone half his age, where he attacks Riley and Clapton, and kills Alexis, all because Riley won't have sex with him. [[SarcasmMode Real mature, Sander]].]]
* PuttingThePalInPrincipal: [[spoiler: In the new timeline, not only does Principal Karl Verge end up with his crush, he ends up becoming more likeable, personable, and even cool, with every implication that he became a much better authority figure to his students. He is even part of a band.]]
* SelfDeprecation: Joseph Kahn gets in a couple of shots at himself.
** One character says that the idea of Clapton and Ione dating "makes about as much sense as that stupid movie ''Film/{{Torque}}''."
** When the characters are watching the bootleg work print of ''Cinderhella 3'', they say that the reason that the movie sucks so bad is because they hired a music video director who needed money to cover his coke habit. Kahn's background is in directing music videos.
** In the opening credits, his name is written in puke.
* ShoutOut:
** All of the main characters are based on the stock protagonists from countless teen movies and TV shows.
** Cinderhella seems to be heavily inspired by Franchise/{{Saw}}.
** Billy Nolan's name is a reference to the {{delinquent|s}} boyfriend of the AlphaBitch villain in ''Literature/{{Carrie}}''.
** During the costume party, Riley is dressed like Angela Chase from ''Series/MySoCalledLife''.
* ShowWithinAShow: The {{slasher|Movie}}[=/=]TorturePorn film ''Cinderhella''. Taken to ''Film/{{Inception}}'' levels of films-within-films with the ''Cinderhella 3'' scene.
* SexySoakedShirt: HotTeacher Mr. Kendall is wearing a white linen shirt that gets plastered to his body and goes see-through when Clapton sets of the sprinklers.
* TheSlacker: Clapton Davis is a lazy student who wants to start a music website. Clapton's grades are poor, prompting Principal Karl Verge to give him an ultimatum: either get an A/Save the world, or be expelled. [[spoiler: Clapton ends up doing both alongside Riley, the world saved being Grizzly Lake, and the A for effort in 1992.]]
* TheSnarkKnight: Riley has a very smart mouth, and doesn't hesitate to make wisecracks at the expense of others, including herself.
* SnuffFilm: Principal Verge refers to the tape from the party as this, given how it caught [[spoiler:Billy's]] death at the hands of Cinderhella.
-->"Who taught you how to make a snuff porno? Music/LadyGaga?"
* SoapboxSadie:
** Riley is demonstrated to be a very Social Justice oriented, unabashed animal rights activist, particularly in the debate with Gord. Her getting whooped in that debate triggers an existential crisis that ends with the former vegan eating a burger and trying to hang herself.
** Gord himself is very outspoken with regard to anti-piracy and believes that ''not'' eating meat is morally wrong. [[spoiler: That's because he's a vegetable-based alien lifeform, who is leading the invasion of Earth in order to stop vegans like Riley from eating his kin.]]
* StylisticSuck: The ''Cinderhella'' movies play out like every teen slasher[=/=]TorturePorn cliche come to life.
* TakeThat: An offhand remark that more kids have been conceived to Music/{{Oasis}} than any other [[Music/TheBeatles Beatles]] cover band.
* TimeTravelRomance: [[spoiler:Ione and Verge.]]
* TimeyWimeyBall: Thanks to Sloan and Ione's FreakyFridayFlip, Elliot's time warp, and the time-traveling bear.
* TooDumbToLive: [[spoiler: Sander may have avoided a [[{{Pun}} Grizzly death]] if he had let go of the axe he had been holding when it was being pulled by the Grizzly time machine's magnetic field.]]
* UnusuallyUninterestingSight:
** The kids walk past [[spoiler:Verge's]] dead body as though he wasn't even there.
** The same thing happens to Riley, hanging from a noose in the school hallway.
* VillainousCrush: [[spoiler: Sander has the hots for Riley, and when she rejects him, he decides to commit mass murder; while he fails to blow up Grizzly Lake in the past, he succeeds in killing Billy and Taylor in both timelines, then attempts to kill Clapton for ending up with Riley, as well as Riley herself for rejecting him.]]
-->[[spoiler: '''Sander''':]][[spoiler: It breaks my spirit to see that bra size wasted on someone like you.]]
* VomitIndiscretionShot:
** Clapton pukes in the school urinal after being confronted by Billy.
** [[spoiler: Riley pukes after tripping Billy during the latter's fight with Clapton.]]
** Billy himself pukes acid multiple times in the movie, [[spoiler: including shortly before he is dismembered by the killer.]]
* WardrobeMalfunction: Riley has one at the party as a result of getting felt up by Sander, causing a guy with a video camera to film her bare breast for seven seconds.
* WildTeenParty: Subverted. It's played as a particularly subdued affair.
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