Any [[DeusExMachina speculative fiction contrivance]] for inserting sex where it would otherwise [[WillingSuspensionOfDisbelief be implausible]]. When used properly, this trope can be used to explore sex-as-metaphor. When used poorly, it's just an excuse to [[PornWithPlot dress up pornography as plot]]. Most examples probably fall somewhere in the middle.

Incidentally, semen has traditionally been associated with vitality, LifeEnergy, holiness, etc in various cultures, and the sex act itself with fertility (agricultural, that is) rites and seasonal change, so there's a bit of mythological justification for this trope. Though plenty of phlebotinum works [[VirginPower the opposite way]].

Overlaps in places with IntimateHealing and ThePowerOfLove. If the DeusSexMachina had not been foreshadowed before in any way, it's also a case of CoitusEnsues. See also MateOrDie, AliensMadeThemDoIt, and LevelUpAtIntimacy5.

If you're looking for the trope about ''actual'' deities having romance or sex, that's DivineDate.

[[noreallife]]
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!!Examples:

[[foldercontrol]]

[[folder:Anime and Manga]]
* Generally speaking, this is actually a ''[[BleachedUnderpants huge problem]]'' in the Japanese "nerdcore" industry, especially with semi-professional video games and animated projects. Full-blown porn is still considered a shameful thing to produce; however, including blatant sexuality in a work even when it doesn't make a lot of sense or is a bit disjointed from the narrative guarantees sales from a certain section of the population, and a lot of companies have built their initial fortunes this way, despite the damage to their reputations and the fact that the sexual content is often shoe-horned into stories that are more than narratively sound enough to stand on their own without this kind of "propping up". {{Nasuverse}} and Key games (such as ''VisualNovel/{{Kanon}}'' and ''VisualNovel/{{AIR}}'') are the most notorious examples of this practice, although it's worth pointing out that those involved with said franchises are now [[BleachedUnderpants bleaching furiously]] since the initial appeal of sexuality paid off.
** Considering the fact that TYPE-MOON's popularity exploded after ''VisualNovel/FateStayNight'', but that they still continue to add nudity, shows that it wasn't simply for sales appeal.
** Key games do not even bother trying to pretend that the sex is in any way important to the plot. Pretty much 'we know you thought she was cute, here's a picture of her naked, back to [[{{utsuge}} the sad story]].' Which is why they made an under 18 version of ''AIR'' (for those who just want the story) and ''CLANNAD'', which doesn't have any sex involved. (Unless you count ''[[HotterAndSexier Tomoyo After]]'', that is.)
*** Kano in ''VisualNovel/{{AIR}}'' is told by [[spoiler:Hijiri]] that she will gain magical powers once she "becomes an adult". In the original [[{{H-Games}} H-game]], you can guess which way she takes this. (Pun very much intended.)
* In the movie ''NinjaScroll'', one of the ninjas was able to control women. Initiating this mind control involved the victim tied spread-eagle and naked from the waist down while the ninja licks his fingers to lubricate them. Further details not needed.
** The woman in question was incredibly poisonous; having sex with her led an otherwise unbeatable rock-man to [[spoiler:fall to pieces]].
** Also, contact with said woman ''while'' you're poisoned will actually negate and cure the poison. You can see what route she decides to take with this when she discovers this.
* A prime example of this is ''Daiakuji'', where the protagonist comments upon his release from prison about how he has become weak with absence of sex. Throughout the series the protagonist becomes more powerful as he subjugates women.
* Cruelly subverted in ''Manga/{{Basilisk}}'', where one of the Koga ninjas is Kagerou, a beautiful and sexy BrokenBird who will never be able to have sex with a man she truly loves since [[BlessedWithSuck her breath becomes poisonous]] when she's aroused.
* In ''VisualNovel/FateStayNight'', while most Masters recharge their Servant's mana by simply transferring it to them directly, Shirou does not know how to do this, so the only other option is to have sex with his Servant Saber.
** As [[TheHillOfSwords one fanfic]] put it:
--> "In order to stop a truly powerful enemy, you had to have sex with two women at once, and that it actually made one of them powerful enough to win against a foe you had no hope of defeating before?"
** In a similar vein, in the ''VisualNovel/{{Tsukihime}}'' VisualNovel the Synchronizers' ability work through [[IsThatWhatTheyreCallingItNow fluid exchange]], as well as [[spoiler:suppressing Roa in Ciel's ass]] in an earlier route. Meanwhile, the pseudo-sequel ''Kagetsu Tohya'' is a subversion, as there's a perfectly viable alternate solution you can take, Len just doesn't like it as much. Hey, he ''is'' [[MemeticSexGod Shiki Tohno]].
* The giant mechas in the anime ''VisualNovel/LimeIroSenkitan'' are powered by someone having sex with their pilots.
* In ''{{Amaenaideyo}}'', Ikkou is a male novice at a Buddhist temple populated by a harem of Buddhist nuns. His powerful spiritual ability for combating ghosts and such is unleashed via lust, so the plot resolution is invariably one of the girls disrobing, or being disrobed, in order to release his power.
* ''CrimsonSpell'' offers up a twofer: the sorcerer Havi keeps Prince Valdrigue's SuperpoweredEvilSide under control with sex, which apparently also has the effect of helping fuel Havi's own magical powers. Go figure.
* The ''{{Gantz}}'' anime toys with this: while Kurono is still unused to using the Gantz suit, he theorizes that it only functions when he is turned on. This theory is only referenced in one scene and the suit seems to function consistently after that, so either Kurono was wrong and the suit also responds to other kinds of "excitement," or he's turned on a LOT. (Knowing Kurono, the latter is at least as likely as the former.)
* Inverted in the oh-so-wonderfully named manga ''MyBalls''. The series begins with the Queen of Terror being [[SealedEvilInACan sealed into Satou Kohta's right testicle]], meaning the world will end should he ever, well, um, you know. Cue the sexy legions of Hell to use every technique in their arsenal to get in his pants, hilarity ensues.
--> "My ejaculatory control muscle is at it's limits!"
* In ''GenesisOfAquarion'' and its sequel ''AquarionEvol'' combining mechas causes all of the pilots to experience something BetterThanSex. Each time they combine, the audience gets a load of screaming, rainbow-coloured naked bodies. The entire series has multiple metaphors to sex and maturity, but those are justified due to many of the characters being teenagers.
* Played ridiculously straight in ''Yuria100Shiki''. Yuria is a {{sexbot}} [[IJustWantToBeNormal trying her best]] to not be one. However, despite her best efforts, she inevitably winds up rationalizing some reason to have sex with Shunsuke. HilarityEnsues.
* Urd from ''Manga/AhMyGoddess'' tries to invoke this trope in her introductory chapter of the manga. She tells Keiichi that he has to have sex with her in order to repair/recharge the system force that keeps him and Belldandy together, and that if he doesn't have sex with her, Belldandy will have to return to heaven. It turns out to be a trick though and Belldandy comes in and reveals that it was just a trick before anything happens.
* Kinji's [[SuperMode Hysteria Mode]] from ''HidanNoAria'' only gets activated when he becomes sexually aroused.
* This happens in the final episode of ''Anime/PantyAndStockingWithGarterbelt'' when [[spoiler:Brief's stiff key is the key to unlock Hell's Gate, and the only way Panty can save the day is getting it to go down.]]
* [[spoiler: Double subverted]] in the ''VisualNovel/ElevenEyes'' anime. In episode 11, Misuzu has sex with Kakeru to power him up (or something along those lines). [[spoiler: Subverted in that they were still unable to defeat [[BigBad Liselotte]] and prevent [[TheEndOfTheWorldAsWeKnowIt the end of the world]]]]. [[spoiler: Double subverted because none of that happened and was all part of Kakeru's vision]].
[[/folder]]

[[folder: Comic Books ]]

* Phil Foglio's ''XXXenophile'' sometimes uses this, but usually with a comedic twist. For example, the one where the nymph mentions casually in passing that people's orgasms keep the earth from exploding, or the one where a {{time travel}}ler from the future has to find out whether it's worth bringing back women through cloning, but it turns out [[spoiler:it's just a [[strike:normal]] exceptional couple roleplaying]]. Foglio is careful to make sure the sex always remains consensual and un-forced, no matter how weird the situation gets. For example, there is a ghost who can be sent on to heaven by having sex with the specific guy she was fantasizing about when she died, or he can just ''tell'' her to go. The sex is not obligatory.
* The old ''Penthouse [=ComicX=]'' series loved this trope:
** Hericane's powers came from a combination of explosives... and a mouthful of Captain Adventure's (the current one's father) [[UnusualEuphemism baby-batter]].
** Dr. Dare was a DistaffCounterpart CaptainAmerica-DocSavage hybrid who gained temporary super strength after an orgasm. (Unfortunately for her, [[ButThouMust masturbation didn't seem to work]])
** In ''Scion'' (NOT the Creator/CrossGen one), a dormant Scion's powers could only be activated through sexual contact with a Scion with active powers.
* In Creator/AlanMoore's ''{{Promethea}}'', Jack Faust agrees to teach Sophie Bangs about magic in return for sex with her alter-ego, Promethea. [[spoiler:There is a justified reason for this, as Faust uses the opportunity to explain the relationship and symbolism of "male" and "female" magic. But also 'cause Faust is horny, and it allows for an issue-long sex scene. And it's traditional for a wizard to be an utter asshole.]]
* ''ComicBook/{{Hellblazer}}'' - In the Fear Machine arc, Constantine and his two ex-girlfriends (a hippie and an earth goddess priestess) save the day with a threesome (and "female" magic). The two ladies had spent the previous few months on an island (a character calls it "one of those woman magic places") where the magic was powered by love and orgies.
* The John Byrne comic ''ComicBook/NextMen'' has sex with the Next Men as a catalyst which [[SuperEmpowering bestows super-power mutations]] on normal humans.
* In ''TopTen: Beyond the Farthest Precinct'', the Hell Ditch Pilgrim is revealed to have gotten his powers in the previous ''TopTen'' series by catching S.T.O.R.M.S., a mutating disease, from a prostitute.
* ValiantComics' ''[[ValiantComics Shadowman]]'' had to have sex with [[ReallySevenHundredYearsOld young-looking]] Voudun priestess Mama Nettie on a regular basis to ''keep'' her young and powerful, so she could help him control his mystical DarkSide.
* Pandora Breedlswight from ''ComicBook/{{Ironwood}}'' is possessed by a demon that can be summoned at will (taking her place), but can't be dismissed by anything else than an orgasm. This is part of a family curse, running on male members, until Pandora happens to be the last of her line. Her male ancestors seemed not to care of the curse, anyway.
* In the ''ComicBook/BuffyTheVampireSlayer'' comics, Willow uses the power of orgasms to power the spell used to contact her patron goddess, Saga Vasuki.
* In ''ComicBook/HackSlash'' the female slasher Acid Angel has corrosive vaginal juices as her main weapon. Ew.
* In Jean Van Hamme's and Grzegorz Rosinski's ''[[ComicBook/TheGreatPowerOfChninkel The Great Power of Chninkel]]'' (''Le Grand Pouvoir du Chninkel''), Volga the Soothsayer must have an orgasm in order to deliver prophecies.
* Provides FanDisservice in ''{{Incorruptible}}'' #16, where the city's water supply is magically transformed into some noxious substance by the unattractive and obese sex magicians Nebuchadnezzar and Loretta Grass, whose spells only last as long as they're [[UnusualEuphemism "chanting"]].
[[/folder]]

[[folder:Fanfiction]]
* In the extensive ''Franchise/StarTrek'' AlternateUniverseFic ''Firing Solution'', Pon Farr and the Vulcan mating cycle and cultural history are examined in far more depth, and at least half the mechanics of TheFederation and the power shifts in the galaxy prove to be directly attributable to Vulcan Nookie.
* In a ''Series/TrueBlood''[=/=]''Film/{{X-Men}}'' crossover ''[[https://www.fanfiction.net/s/6051043/1/Survival-of-the-Fallen Survival of the Fallen]]'', it turns out that [[spoiler:Rogue of all people]] is a succubus. In this case Succubi aren't outright demonic, and appear to go either way morally speaking. They seem more like talented sex oriented energy vampires, without actually needing to take energy. Considering the character this happens to, this is most ironic, and a major plot point.
* The ''Anime/NeonGenesisEvangelion'' doujin ''Manga/ReTake'', takes this to... a much lower level than would be expected, considering the author's previous work! This is done properly in chapter one. All 5 chapters thereafter just play dress-up-the-sex-and-hope-the-audience-doesn't-notice.
* In Chapter 34 of Fanfic/LightAndDarkTheAdventuresOfDarkYagami, the Creepy Chick turns out to be able to time travel via "lots of sexing"
* In the VisualNovel/FateStayNight[=/=]Sekirei crossover Fanfic/InFlight, by [[http://www.fanfiction.net/u/1263379/gabriel_blessing Gabriel Blessing]] Shirou uses this to make Akitsu his Sekirei.
* In the LegendOfZelda fanfic MyInnerLife, the main couple decide to got o a monastery that performs "pagan bonding rituals" for married couples. The four-part ritual is broken down into the physical bonding, the mental bonding, the spiritual bonding and the sexual bonding. Guess what Link and Jenna need to do for the last one.
* It's a fairly common trope in ''Literature/HarryPotter'' fanfic that werewolves' condition makes them perpetually horny. It probably originated with the [[SlashFic Remus/Sirius]] ship, but has since spread.
[[/folder]]

[[folder:Film]]

* In ''Film/{{Ghostbusters}}'', it's strongly implied that Dana Barret, while possessed by Zuul the Gatekeeper, had sex with Louis Tully, who was possessed by Vinz Clortho the Keymaster ([[FreudWasRight key, gate, get it?]]), in order to free BigBad Gozer. In fact, a deleted scene from the movie has Venkman explicitly asking Dana if she and Louis "did it".
** Almost certainly related to an earlier, often deleted exchange.
-->'''Zuul/Dana''': I want you inside me.
-->'''Venkmann''': It sounds like you've got at least two or three people in there already... might get a little crowded.
* In the 1987 RomCom ''My Demon Lover,'' the hero is under a curse that makes him turn into a demonic monster whenever he gets turned on. When his love interest is captured by the real (and likewise cursed) monster of the story, her best friend seduces him to enable him to make the transformation and fight the bastard. (This makes the love interest jealous, despite the obvious necessity.)
* Averted in the first ''Film/{{Ghoulies}}'' film. A would-be Satanic wizard paints a ritual pentagram under his bed, then attempts to have sex with his female companion there. Realizing that he's chanting under his breath, she catches on that it's one of his sick magical experiments, and kicks him out of bed.
* In the Israeli film ''The Revenge of Isaac Finkelstein'' - there's a ghost of an ancient monk who's invisible to everyone except the protagonist, unless he has a hard-on, which makes him visible (or semi-transparent, depending on the hardness of his 'on').
* In the movie ''Zerophilia'', people with the "Z chromosome" change gender when they have sex with another person with the Z chromosome, or (when their powers first manifest) simply when they reach orgasm. (No, it's not quite as pornographic as it sounds.)
* In ''Film/CatPeople'' the remake, the werepanthers' transformation is triggered by sex.
[[/folder]]

[[folder:Literature]]
* OlderThanFeudalism : In ''Literature/TheOdyssey'' Odysseus is forced to have sex with Circe to save his crew from being swine. Definitely forced.
* In Creator/StephenKing's ''Literature/{{IT}}'' (but not in TheFilmOfTheBook for [[MediaWatchdog obvious reasons]]), Beverly Marsh [[spoiler:has sex with the other members of the Losers Club (all six of them, one after the other, in a sewer) in order to re-forge the connection between them after defeating {{IT}} as pre-teens]]. Apparently it's supposed to be a metaphor for moving from childhood to adulthood.
** Another level of irony (and possibly a FamilyUnfriendlyAesop) also exists here, when you contrast this with another scene in the book. Beverly's father is portrayed as an abusive, overprotective, borderline psychopath. When he learns that Beverly has been playing with boys, he insists -- violently -- on ''physically'' checking to see if she's still a virgin. [[spoiler: Fortunately, she escapes him.]] At this point, she still is, and the scene plays out like an [[RapeAsDrama attempted rape]].
*** The real irony of the matter is that Beverly is inspired to [[spoiler:have sex with the boys]] ''because'' of what her father did. He put the idea in her head.
** Creator/StephenKing does this a lot. In his ''Franchise/TheDarkTower'' series, [[spoiler: in order to retrieve Jake from the other world, Roland has Odetta/Detta distract the oracle.]] In the series, oracles are demons that feed on sexual energy (i.e., [[HornyDevils incubi/succubi]]). Go on, guess the best way to distract one.
* The ''Literature/WildCards'' series has several examples:
** Fortunato has "magickal" powers that must be fueled by tantric sex. Fortunately for him, he's a pimp with easy access to geisha-style prostitutes.
** The character of "Blowjob" must be sexually excited in order to breathe life into inanimate objects.
** Roulette can [[OutWithABang kill by unleashing poisonous vaginal secretions]]. (Does somebody have issues?)
** "Prime" was able to give the "Jumpers" their power to [[GrandTheftMe switch minds with other people]] by having anal sex with them.
** [[spoiler: Water Lily gets the power to cure Jokers by intercourse]] after being infected by the Sleeper's new strain of Wild Card virus.
** Genetrix lay eggs which hatch into short-lived children with ace powers fitting her needs when engaging in sex.
* The eponymous protagonist of the ''AnitaBlake'' series has had her supernatural powers become more closely tied to sex with each passing book, resulting in a situation where the solution to any problem is for her to have sex with somebody or something. That makes this also an example of WhenAllYouHaveIsAHammer... or possibly, [[IncrediblyLamePun in this case, a screwdriver]].
** And in the same author's ''Literature/MerryGentry'' series, it's eventually explicitly stated that the power of Faerie comes from the natural order and thus can only be awakened through fertility rites. This ''does'' allow the choice of [[MateOrDie sex or death]] (killing in battle or sacrificing loved ones), and Meredith isn't always viewed favorably for favoring the "soft" option (except by the beneficiaries of it). Since the protagonist here has been chosen to [[ReallyGetsAround revitalize the entire magical world]]... this series basically starts sexually at the point ''AnitaBlake'' was at that time, with a main character who [[AnythingThatmoves never had any of Anita's former inhibitions]].
* In Creator/LarryNiven's ''Literature/{{Ringworld}}'' series, depending on the particular human subspecies involved, when two inhabitants from different subspecies meet, the standard greeting may be ritualized sex ("Rishathra" is the word for this among the species our protagonist meets in ''The Ringworld Engineers''), though for some cultures it is taboo. (People still talk about Niven showing up at a sci-fi convention in the late 1970s wearing a button that said "I have sex outside my species.")
* In the later ''Literature/{{Dune}}'' novels, an offshoot of the Bene Gesserit arise who use sex as a form of [[MoreThanMindControl hypnosis]] -- it's just ''that'' good, apparently. Numerous galaxy-spanning, [[GambitRoulette wheels within wheels]] plots are derailed when it is discovered that there is a man with the same power. A-whoops! Of course, it ''is'' [[MemeticSexGod Duncan Idaho.]] Given his place in the series as the designated CosmicPlaything, this is simply karmic balance for him.
** And this man trains other men to use that power. Leading to a guerilla war fought mostly using SEX. Really awesome sex. Where do I sign up?
* In the ''Literature/{{Illuminatus}}'' trilogy, the goddess Eris has sex with multiple men to return to God mode. The insanely high amounts of sex in that book build up a pretty good reader tolerance to implausible sex acts, but that one takes the cake.
* In the ''Literature/TheBookOfAllHours'' duology by Hal Duncan, especially in the second book, "Ink", tantric sex apparently makes it easier to travel between the various alternate realities. Several kinds of technology also seem to be fuelled by sex, using so-called "orgone energy" as a power source.
* Jennifer Stevenson's ''Trash Sex Magic'' is ''entirely'' about this trope, as its title might well imply.
* In Michael Swanwick's ''Literature/TheIronDragonsDaughter'', protagonist Jane learns to use sex magic to boost her own spellcasting ability.
* Inverted in S.M. Stirling's alternate-history novel ''ThePeshawarLancers'': The heroine has been (incestuously) bred for [[PsychicPowers clairvoyance]]; this power (1) only works for virgins and (2) ultimately drives the holder to madness and death. You can guess what the hero does to save her.
* In ''Literature/AmericanGods,'' a perversion of the Queen of Sheba [[spoiler:literally devours a man through the act of coitus, apparently to substitute for the worship she wasn't getting to sustain herself.]]
** Also, there is importance in [[spoiler:Shadow's in-dream sex with Bast.]]
** Not to mention the [[spoiler: Ifrit who exchanges bodies through sex]]
* In Dan Simmon's ''[[Literature/{{Illium}} Olympos]],'' one of the main characters finds a slumbering princess who's been kept in stasis for centuries. The only way to wake her? Climb in the stasis chamber and give her some lovin'.
* Ramona Random, a Black Chamber agent in Creator/CharlesStross's ''[[Literature/TheLaundrySeries The Jennifer Morgue]]'' has a succubus bound to her. If she doesn't have sex, it [[MindRape eats her mind]]. If she does have sex, it [[OutWithABang kills the partner instead]]. She's employed as an assassin, naturally.
* In "Literature/SunMoonAndTalia", a fairy tale of the "Literature/SleepingBeauty" type (and probably a major influence on the more famous Creator/CharlesPerrault version), the princess stays asleep until she has twins and one of them suckles the poisoned needle from her finger.
** One version says that what wakes her up is her first baby's cry.
* This happens with Leah, Henry, and Tony in ''Literature/SmokeAndShadows'' Leah is tied via Demongate to a sex demon named Ryne Cyratane, but the demon doesn't comprehend homosexuality. Tony the gay wizard can tell that Ryne Cyratane wants to communicate with him, but literally can't see him without the sexual connection. Ergo, Tony's BiTheWay ex Henry is enlisted for a save-the-world threesome that will enable Tony to talk to the demon.
* ''[[Literature/KushielsLegacy Kushiel's Dart]]'' and its sequels contain any number of DeusExMachina scenes where the main character resolves whatever problems exist in the kingdom through having sex with someone. This is because she is magically gifted with ''really'' enjoying every kind of kinky sex...
* ''Literature/{{Perfume}}: The Story of a Murderer''. [[spoiler:In the end, the man finally completes the "perfect" perfume he had been attempting to create the entire movie, and drops the vial on the ground while being led to his execution for his multiple murders and distilling of young women's essences. The smell is so beautiful, everyone in attendance participates in a spontaneous orgy, and the man escapes in the chaos.]] It's funny what you can accept when the movie logic is introduced early and kept consistent, really...
** Same for the film of the book.
* ''The Secrets of Jin Shei'' - although Lihui is a powerful mage without resorting to this, it's implied that he can only keep his strength and immortality by stealing other people's energy. [[spoiler: Unfortunately for Nhia, to create the psychic link he needs for this ritual, he has to create a physical link as well. Guess how.]]
* In ''Battle Circle'' by Piers Anthony, the heroine is trapped in a Minotaur's maze. The hero goes in to rescue her. He finds her but they are unable to escape and the Minotaur is closing in on them. The hero remembers that the Minotaur is only interested in virgins and he can save the heroine's life by another means.
* ''{{Dragonlance}}: Heroes: Vol. 1''. Huma, Knight of the Sword. One of the final gambits of Takhisis, Queen of Darkness is that she could show him... things. [[IncorruptiblePurePureness He refuses.]]
* In ''Literature/ASongOfIceAndFire'' [[spoiler: Melisandre the Red Priestess/sorceress]] is able to spawn shadow demons that can be used as assassins. She needs sex in order to create them, but it apparently weakens the man she uses; she herself states that [[spoiler: Stannis']] declining health is due to her using him in that way, and so tries to convince [[spoiler: Davos Seaworth]] to help. It is possible that her somewhat FoeYay-ish interactions with [[spoiler: Jon Snow]] might be a prelude to trying to use him in this way.
* In Alex Prentiss' novel ''NightTides'', the main character [[IsThatWhatTheyreCallingItNow communes]] with lake spirits, but in return, she must help everyone who needs it.
* In Peter S. Beagle's ''The Folk of the Air,'' there is a fairly random sex scene between an ancient evil spirit in a boy's body and a young ([[{{Squick}} very young]]) woman for the purpose of "tantric sorcery."
* In the [[Literature/TheDarkElfTrilogy first book of the Drizzt series]], there is an orgy at the academy, seemingly something they do traditionally every year. The priestess with the best grades has intercourse with a summoned demon, while around her all the other female students pick a male student and get it on.
[[/folder]]

[[folder: Live Action TV ]]
* In ''Series/{{Smallville}}'', Clark's discovery of his [[EyeBeams Heat Vision]] was linked to him being aroused. I wonder what ''that'' [[DoesThisRemindYouOfAnything reminds you of...]] Hence the FanNickname "Eyejaculation".
* In ''Series/TheOthers'', two of the characters have fallen in love, but the interaction of their respective psi-powers causes powerful energy discharges whenever they touch. In the finale, as part of a series of strange happenings that works to break the group apart, they find that they can now safely touch one another. This tragically turns out to be an illusion created by an otherworldly evil force, which lifts while they're having sex. Cue the ''entire building exploding''.
* The eponymous [[EarthShatteringKaboom planet-killing]] spaceship of ''Series/{{Lexx}}'' would only respond to whoever held its symbiotic energy key in their brain. The host would involuntarily release the key into whoever else was nearby if brought to the very edge of death... or the very extreme of sexual ecstasy. Interestingly, this was ''not'' equivalent to orgasm; actual sex usually did nothing to trigger the key, whereas just the ''anticipation'' of sex with a character's [[OneTruePairing One True Love]] thrice ''did.''
* ''Franchise/StarTrek'' has Pon Farr - every seven or eight years Vulcans get a hormone craze that is generally only to be satiated by sex. Either they [[MateOrDie do or die]], literally. Fortunately, [[spoiler: the holodeck version counts]]. Or [[spoiler:they find an alternative way to give said Vulcan similar emotions to sex, e.g. extreme anger/rage/sadness, like believing that you killed your best friend]].
** An interesting sign of increasing Flanderization as the franchise has gone on, as well. Prior to ''Star Trek: Enterprise'', only Vulcan ''males'' were afflicted by Pon Farr. Dialog also confirmed it was strictly a male condition. Somehow this mutated until it now affects ''all'' Vulcans. The presence of [[MsFanservice Jolene Blalock]] may have had something to do with that....
[[/folder]]

[[folder: Tabletop Games ]]
* ''TabletopGame/MageTheAscension'' gave us the Cult of Ecstasy. Sure, they didn't just revolve around using sex as magical foci (they also used drugs, music, meditation, etc.), but that was easily the aspect with the most humor potential.
** ''TabletopGame/MageTheAwakening'' carries it on with a [[PrestigeClass Legacy]] called the Whipping Boys. They don't use sex, exactly, but BDSM, using deeply intensive "sessions" to find revelation in a place beyond pain and pleasure.
* Both played straight and inverted in ''TabletopGame/UnknownArmies'' with the tastefully named magick school of Pornomancy. [[spoiler: Followers get charged up from mechanically reenacting scenes from porn films starring The Naked Goddess, a porn star who got promoted to the [[PowersThatBe Invisible Clergy]]. The inversion comes from the fact that if they ever have sex with anyone for any other reason than charging up, all their stored power goes away.]]
* In ''TabletopGame/{{Warhammer}}'' and ''TabletopGame/{{Warhammer 40000}}'', the [[EldritchAbomination Chaos God]] Slaanesh and its followers have this reputation, however ''any'' excessive and obsessive mindset can cause empowerment in his/her name, not just sex. The Emperor's Children Legion were seduced by Slaanesh due to their single-minded obsession with purity and the excesses they would commit to achieve and maintain it, Noise Marines are focused on [[ThePowerOfRock extremes of psychically-charged music]], and The Masque (most powerful of all Daemonettes) gets its power from basically being the best dancer in the universe, able to entrance even the Chaos Gods.
* One of the many strange and juvenile things that comes with the territory when people publish sex-based supplements for ''TabletopGame/DungeonsAndDragons'' (officially, the legendarily bad ''Book of Erotic Fantasy'', as well as ''Encyclopedia Arcana: Nymphology'' and ''Quintessential Temptress'', with the latter two basically a collection of juvenile snickering). Tantric magic is [[IncrediblyLamePun just the tip of it]].
** And ''Sisters of Rapture'', which kicks it up a notch with full-frontal nudity on nearly every page -- some of it showing tavern scenes and the like to drive the point home that these characters ''never wear clothing at all''.
* In ''BlissStage'', the power of a Pilot's DreamWorld HumongousMecha is based on the intimacy level of their relationships. To get the maximum of Intimacy 5 with anyone you're not related to, you have to have sex with them. It's quite disturbing considering the Pilots are teenagers, and the Anchors that produce their mecha and the various supporting characters are either teenagers, or full-out children.
** This is mechanically discouraged, as well: [[YouLoseAtZeroTrust losing an Intimacy 5 relationship to trust issues can destroy an entire RESISTANCE...]] Not to mention that being overly powerful leads characters to gain Bliss more quickly, and reaching 108 Bliss leads to very bad things -- start with "your character dies horribly" and work your way up from there.
* TabletopGame/TwilightSparklesSecretShipficFolder is basically this as a game. There's even a card called Divine Intervention! Though to be fair, it's less "sex" and more "romance"...
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[[folder:Theatre]]
* In Richard Strauss's early opera ''Feuersnot'', Kunrad punishes Diemut's rejection by magically banishing fire from the town until she gives herself to him.
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[[folder: Video Games ]]
* Completely inverted in ''PlanescapeTorment'', where the token demoness is a reformed succubus, runs an Intellectual Brothel and refuses to feast on horny men for her power. She is the healer of the party, but not quite the [[IntimateHealing Intimate Healer]]; her kisses are an attack.
* In ''VideoGame/GrandTheftAuto'' games, players gain health from prostitutes. This method can be used to greater-than-max health.
** The fourth one added strippers, who unfortunately stay in bra and panties. They heal the same amount prostitutes do, but they cost more.
* The fangame ''VideoGame/QuestForGlory 4.5'' also allows the hero to be "healed" in a brothel. Needless to say the company owning the original game wasn't too happy.
* A possible choice at the end of ''VideoGame/DragonAgeOrigins'' is for [[spoiler:Morrigan to conceive a child with either Alistair, Loghain or the male player character in order to make a receptacle for the Archdemon's soul; otherwise a HeroicSacrifice is necessary. Unlike other examples of this trope, this choice is far more serious than it looks, and when pressed Morrigan refuses to explain exactly what she'll ''do'' with the kid once it's born.]]
* ''BrutalLegend'': Apparently, years of orgy and violence can cause a [[spoiler:"temporal perversion" aka ''time travel'']]. It's the Tainted Coils we are talking about, however, it's almost expected.
* Apparently sex is required to gain the right to [[spoiler:become an Eternal]] in ''EienNoAselia''. FridgeLogic sets in when you realize that [[spoiler:Kyouko and Tokimi]] apparently did not have to. Maybe [[spoiler:Tokimi]] made the whole thing up?
* In ''EmbricOfWulfhammersCastle'', Huraine (goddess of love, lush scenery, strawberries and chocolate) requires this of her worshipers in their rituals, which is good news for Dorcas. One of the MultipleEndings even has the Duchess becoming the centrepiece of one of these rituals.
** Most of the game is this trope, really, although it's more nudity and gratuitous lesbian fanservice than strictly intercourse. [[spoiler:Carmina's route is probably the one that fits the implausible/inappropriate part; not many people would confront their rapist just to immediately forgive them for it, and then pursue a romantic relationship.]]
* Though it cuts short with mere implications in ''VideoGame/DuelSaviorDestiny'', sex is apparently a necessity for [[spoiler:Rico/Oltara]] to contract with Taiga. And wow, talk about bad timing: They're technically in the middle of a fight.
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[[folder:Webcomics]]
* ''Webcomic/SuperStupor'' has one ''[[http://www.superstupor.com/sust11262007.shtml comic]]'' where Magic Eye reveals that his superpower is the ability to compel anyone to tell the truth... as long as his penis is inside them. (He doesn't like to do it to someone who hasn't given consent, but "you'd be unpleasantly surprised who does.") When asked how he discovered this power, he remains silent and mortified while a third character chimes in that this is "[[NoodleIncident the best divorce story ever!]]"
* ''Webcomic/MenageA3'' teeters on the brink of this, with a lot of implausibly rapid and successful seductions; [[ReallyGetsAround Zii]] can be a particular repeat offender, especially in early strips. However, these ''are'' essentially seductions on conventional lines, admittedly including people jumping each other (consensually) for rapid stress relief, so events in the comic perhaps never quite fit the trope.
* ''Webcomic/{{Sonichu}}'', of all comics, has this in issue #8 with Silvana, whose "nectar" is a poisonous and paralytic sleeping agent she secretes during sex. After transforming herself to look like Bubbles, she makes out with Blake, knocks him out, and advances what little plot there is in the comic in the first place.
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[[folder: Web Original ]]
* Now, the vast majority of ''IlivaisX''s HumongousMecha are fairly normal and realistic. But the eponymous one only registers with one who possesses "Love" Drive Core (or has a similar demeanor), but the way it works makes it more similar to lust. This kicks off numerous broad themes involving the border between love and lust and whatnot, but the most clear example of an out-and-out DeusSexMachina is the Love Drive Core attack, which can basically only be used via orgasm.
* Go to asstr.org's author's page and look up [[http://www.asstr.org/~sgray/ Stephen Gray]] (NSFW or kids). Marvel at both the sex as mind control and [=demons/potions/=]AliensMadeThemDoIt. Notice how vanilla most of the sex is. Wonder if this is a case of the Machina being extraneous to the sex...
* This shows up a ''lot'' in the Sci-Fi and Fantasy section of Website/{{Literotica}}, though details vary.
* The erotica writer Salamando, aka Salamando Flames enjoys mixing elements of fantasy adventure and superhero fiction into his erotica. Often, sex will in some way be used as a mechanism for mind control, domination, acquiring magical energy, exacting revenge, fueling super powers, or even healing. In the Sex Mage World stories, the entire basis of magical powers (which only women have access to) requires sex and arousal to both activate and continue functioning.
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