History Main / DangerousForbiddenTechnique

* In ''{{Raideen}}'', the titular mecha has the powerful "God Voice" attack, which ends up ruining his vocal cords every time he does it. In the ''SuperRobotWars'' games, Akira will actually end up being unable to speak if you use this too many times before a certain point.

* ''JukenSentaiGekiranger'' features the Ju-Ju-Zenshin-Hen, which allows the user to take on a super-powerful beast-like form. The bad news: transformation is permanent. The worse news: if your technique isn't perfect, your life's gonna ''suuuuuuck.'' A Wolf Fist user winds up transforming into an out-of-control werewolf periodically, but at least he gets restored into his human form. The Fly Fist user (no, really) isn't so lucky, winding up an anthropomorphic fly who is about the size of a mouse. He ends up getting swallowed by an evil Chameleon Fist user and is resurrected along with her after she dies...
* ''MahouSentaiMagiranger'' also has one. Anyone who uses Chronogel's forbidden time spell will die via getting sucked into a wormhole that appears on their chest while it sucks other things like matter and time into it. This curse was deliberately placed on it - apparently, the use of time magic is so dangerous that ''making sure the universe is screwed if you use it'' is the best way to protect it. Yeeeah.

* ''TabletopGame/MagicTheGathering'' has a bunch of cards that are effectively this. You can't miss them, because they all inform you that ''you lose the game'' after a certain amount of time or if a certain condition is met. For example, [[HourOfPower Final Fortune]] allows the user a free turn at a cost and color that doesn't normally get it, but the user loses the game at the end of that turn if they haven't won yet. [[{{Immortality}} Lich and its variants]] protect you from dying through life loss, but kill you under other circumstances, such as an empty graveyard.

** In the ''Dead Gods'' module, there was a spell called the Last Word that was so lethal, even gods were afraid to use it. This didn't stop Orcus, however. Having been deposed and reduced to an [[NotQuiteDead barely alive]] state, used it in his camaign to restore himself to life and regain his domain in the Abyss. After killing several gods using this spell, he succeeded, but lost the ability to use it. (The gods have since taken steps to prevent anyone from using it again.)

** [[spoiler: Bloodbending, supposedly the ultimate technique of waterbending, which involves moving around the blood in a living body and making that body do whatever you want it to do.]] [[spoiler:Like the Osmosian example above, it is shown that it is detrimental to the Waterbender's sanity, making them AxCrazy and power-driven.]]. To elaborate, [[spoiler:Hama was bent on getting revenge after discovering the technique, Katara almost lost herself while trying to avenge her mother, in which she almost lost control while mercilessly bloodbending the Fire Nation's Guards. Later on, Yakone came out to be an AxCrazy Bloodbender who brought fear to Republic City, and even figured out how to bloodbend without a full moon. Then came his sons, both of whom practiced bloodbending frequently and ended up insatiably power driven later on in their lives, especially Amon.]]. For this reason In ''WesternAnimation/TheLegendOfKorra'' it has actually been declared illegal to use.

Perhaps the technique conducts a horrible toll on the person's [[CastFromHitPoints body]]. Perhaps it's horribly [[KarmaMeter immoral]] or [[SanityMeter damaging to the mind]]. Perhaps it [[SummonBiggerFish calls up monsters that can't easily be controlled]].

** Speaking of the piledriver, an actual piledriver (not the tombstone version that the Brothers of Destruction use) is something that WWE superstars haven't been allowed to use for over a decade due to Owen Hart using the move on Steve Austin, giving him the neck injury that would eventually end his career (no offense to Owen). Come 2013, the fact that Punk used it all, let alone on Cena (who's had a history of neck problems), upped the HolyShitQuotient of the match they were in. Said match is now considered one of the best TV matches in RAW history.

* The diving headbutt, and German Suplex (Which puts a lot of pressure on the spine), especially nasty since they were both moves that ChrisBenoit used...a lot.

* The Forbidden Move in "Webcomic/AxeCop Gets Married": When Axe Cop's opponents at a fighting restaurant in China do a secret move that combines them all into a giant fighter, Axe Cop counters that he knows a move that is ''more'' than secret -- meaning because it's forbidden. The technique has not been explained as forbidden before, but everyone knows about it and panics when he starts to do it, because it will kill everyone in two provinces. The move creates a giant tornado that picks up the adjacent province and smashes your opponent with it. Ultimately {{subverted}}: Axe Cop shows that when done ''correctly'', the move only affects the one opponent, removing everyone else to safety and then putting them back too fast for anyone to notice.

* Subverted in the ''Series/StarTrekTheOriginalSeries'' episode "The Enterprise Incident", where Spock appears to kill Kirk using a powerful Vulcan technique called the "Vulcan Death Grip". In reality, this was part of a plan devised by Kirk, Spock, and Bones to infiltrate the Romulan ship, which involved Spock becoming a FakeDefector; Spock actually only used the more familiar Vulcan Nerve Pinch to render Kirk unconscious and claimed he had killed him to win the Commander's respect. There was actually no such thing as a "Vulcan Death Grip". (They were counting on the Commander to not know that, as Kirk later told Nurse Chapel.)

* '''[[MSPaintAdventures SEPULCHRI-]][[Webcomic/ProblemSleuth TUUUUUUUUUDE!!]]'''

* '''[[Webcomic/EightBitTheater HADOKEN!!!!]]'''

Compare DeadlyUpgrade, CastFromHitPoints, CastFromLifespan, DeathOrGloryAttack. If they constantly survive these it's a case of IThoughtItWasForbidden. See also GodzillaThreshold and LethalHarmlessPowers.

* In ''VideoGame/DiabloIII'', the Wizard differs from the Sorcerer and Sorceress of the previous two games in that s/he practices "dangerous and forbidden magics", which eventually caused him/her to be voluntarily exiled from his/her homeland. This explains why the Wizard has a greater array of ElementalPowers than either of its predecessor classes, including [[{{Mana}} Arcane]] and [[TimeMaster Time]].

[[folder: Tabletop RPG ]]

* Akuma's (Gouki in the original Japanese) fighting-style from ''StreetFighter'' has the Shun Goku Satsu attack, which effectively drags both the target ''and'' the practitioner into hell, where they're assaulted by demons. Until it was mastered by Akuma, it was generally assumed that using it would always be lethal to both. Of course, in-game, it's just a move that does a lot of damage...

** In battle with [[MadScientist Mayuri]], Uryuu activated [[OneWingedAngel Letzt Stil]], which should never be activated unless in absolute need. His [[OldMaster grandfather]] had taught him the technique with the express warning that he should never, ever use the power until he'd learned the truth about his [[MysteriousPast father]]. Uryuu chose to use the power prematurely and paid the price by losing his powers. Later on, he endured a [[YouAreNotReady lecture]] from his father about his premature use of the technique, and then his father [[ParentExMachina restored his power anyway]].

* Ryougi Shiki from ''LightNovel/KaraNoKyoukai'', who has a more outrageously powerful version of the Mystic Eyes of Death Perception, apparently isn't suffering any effects from using that ability. On top of that, she never uses any special glasses, even though she was offered them. It also helps that, unlike the Shiki of ''{{Tsukihime}}'', Ryougi can turn hers on and off, while his is always on.
** In the novels, her Mystic Eyes of Death Perception is ''always'' on. Though there doesn't seem to be a downside.
*** That's because she has the help of a 3rd personality doing the observing nature of death bit without frying her brain for her which Shiki Tohno doesn't have he has to use his human brain which isn't made for this.

* Similar to his [[SonicX anime counterpart]], [[SonicTheHedgehog Shadow the Hedgehog]] can gain an extreme power boost whenever he removes the bracelets from his arms. Unlike the SonicX version, however, it doesn't appear to drastically drain his energy. He only used this power once in ''VideoGame/SonicTheHedgehog2006'' to save himself, Rouge and Omega from [[BigBad Mephiles the Dark]], who used two of the Chaos Emeralds to create an army of clones of himself.
* In the Fate scenario of ''FateStayNight'', Saber comes under this limitation because using her Noble Phantasm requires all the mana she's currently holding to activate (and her flawed summoning means Shirou can't provide her with any), and she ends up facing at least three enemies that require -- or at least seem to require -- the use of it to defeat.
** In Heaven's Feel, projection [[spoiler:(more specifically, projection using Archer's arm)]] becomes this for Shirou. While it puts a strain on him in all three paths, this path spesifically gives him a clear limit on usage, and overuse will kill him. [[spoiler:Which it eventually does.]]
** Furthermore, each Servant has a power known as the Broken Phantasm -- willingly breaking their Noble Phantasm. This renders the servant without their proof of heroism (which for many of them is their weapon), but also inflicts massive one-time damage on whoever the Phantasm is shattered on. [[spoiler:Archer, who can create Noble Phantasm duplicates, routinely uses this technique to compensate for the fact that his duplicates are weaker than the real thing.]]

-->Flashback of Miki being {{CurbStompBattle}}d by her mother, a fat restaurant hostess.

* Ryoga Hibiki's "Shishi Hōkōdan" in ''[[RanmaOneHalf Ranma 1/2]]''. This [[KiAttacks Ki Attack]] is fueled by the user's depression and melancholy. So to acquire more power the user will purposely do things to become more depressed. When Cologne sees Ranma and Ryoga trying to out-depress each other while blasting the technique freely, she compares them to a pair of lions fighting as they roll off a precipice and to their deaths.

*** that's because she has the help of a 3rd personality doing the observing nature of death bit without frying her brain for her which Shiki Tohno doesn't have he has to use his human brain which isn't made for this.

* The protagonist of ''{{Tsukihime}}'' has the Mystic Eyes of Death Perception, which allow him see the concept of death itself on ''everything'' in the form of lines and points. Observing death, however, will lead to insanity, so he has to use special glasses which block his ability. Every time he takes off these glasses his eyes get stronger, but since humans are not meant to observe the nature of death it puts an increasingly enormous strain on him. In fact, in the [[spoiler:epilogue, which takes place a while after any of the routes, it is revealed in his reunion with his 'sensei' that he is literally on the verge of death, in part due to his ability; it is heavily implied that he actually dies just after they part ways.]]
** Ryougi Shiki, who has a more outrageously powerful version of the Mystic Eyes of Death Perception, apparently isn't suffering any effects from using that ability. On top of that, she never uses any special glasses, even though she was offered them. It also helps that, unlike the Shiki of Tsukihime, Ryougi can turn hers on and off, while his is always on.

* Zed in League of Legends is stated to have learned forbidden shadow techniques to defeat his rival Shen, and become a more powerful ninja. It mostly translates to throwing living shadows everywhere.

** [[spoiler: Bloodbending, supposedly the ultimate technique of waterbending, which involves moving around the blood in a living body and making that body do whatever you want it to do.]] Note that it's not dangerous to the user, but it does fit the immoral aspect. In ''WesternAnimation/TheLegendOfKorra'' it has actually been declared illegal to use.

* ''ReBoot'': Bob's fusion with Glitch is viewed as doing the unthinkable by Daemon's adviser, and Bob was fully aware that overusing his new Glitch powers would kill him. Bob comes very close to death when Daemon infects and forces him to overuse his powers to create portals. Bob does imply that the fusion would have been much less dangerous had Glitch not been damaged at the time (which is what necessitated the merger in the first place), however.
* {{Transformers}} examples:

** Also in ''TransformersGeneration1'', Megatron has the ability to draw anti-matter from black holes and pretty much blow up all of his surroundings. It was used about twice in the Marvel comics, where it was explained he didn't often use it because he was liable to kill himself too.

** In ''TransformersCybertron,'' Vector Prime would [[spoiler: greatly tax himself reversing time by a few minutes, and eventually die by using his time/space powers to get the team through the rift separating Gigantion from the normal universe.]]
* In ''JusticeLeague'' [[spoiler:the League had pretty much lost against the Brainiac/Luthor hybrid,]] until TheFlash saves the day by running at extreme speeds (to the point where he was circling the world in mere seconds) [[spoiler:and smacking Brainithor around by repeatedly running into him. Soon enough, he destroys all traces of Brainiac, leaving only a naked Luthor lying on the ground.]] However, in the process he was almost swallowed by the Speed Force from moving so fast, and he says he probably won't be coming back if he ever goes that fast again.

** In battle with [[MadScientist Mayuri]], Uryuu activated [[OneWingedAngel Letzt Stil]] that should never be activated unless in absolute need. His [[OldMaster grandfather]] had taught him the technique with the express warning that he should never, ever use the power until he'd learned the truth about his [[MysteriousPast father]]. Uryuu chose to use the power prematurely and paid the price by losing his powers. Later on, he endured a [[YouAreNotReady lecture]] from his father about his premature use of the technique, and then his father [[ParentExMachina restored his power anyway]].

* Whenever Ichigo used the black getsuga tenshō in ''Manga/{{Bleach}}'' he weakened his hold on his body and allowed his [[SuperPoweredEvilSide inner hollow]] to take control. This was only recently averted when he mastered his hollow side, but there is a noticeable decline in his humanity every time he uses it in battle, resulting in Orihime being just as scared of him as his opponent when he used it in front of her in Hueco Mundo.
** There's also Ishida's complete loss of his powers after his fight with Mayuri, during which he's forced to Do What Must Not Be Done. [[spoiler: He got better.]]
** Ichigo's "Final Getsuga Tenshou" has the side effect of causing him to lose his powers completely. [[ExactlyWhatitSaysOnTheTin That's why it's called "final".]] [[spoiler:This might also explain Ichigo's father's power loss (he only started recovering them a few story arcs back).]]
** Also of note is Yamamoto's use of a forbidden Kido in an attempt to kill Aizen. Hado #96, Itto Kaso (meaning "Single Blade Cremation"), uses the caster's own body as a catalyst to create a massive pillar of fire that erupts from the ground around the caster, taking the shape of a katana's tip. Aizen, unsurprisingly, survives ([[http://www.mangafox.com/manga/bleach/v44/c395/17.html though by no means unscathed]]), but Yamamoto got better - rather than losing his life, as the spell had been implied to require, he only lost an arm.

* In ''Manga/DragonBall Z'', Goku was taught the Kaio-Ken by King Kai, but was told not to use it at more than double capacity. When he fought Vegeta, he had to use it at triple capacity, which hurt like hell, and then ''quadruple'' during the BeamOWar - after that, Yajirobe just patting him on the back made him scream in agony. By the time he fought Frieza, he could use the lower levels without any strain (King Kai had to tell the others that he'd been using it the whole time and wasn't holding back). He eventually used it ''multiplied by twenty'' -- the maximum, and still nowhere near enough to win. ''That'' wiped out his reserves and left him nearly defenseless.