History Main / DangerousForbiddenTechnique

* The "Dead Loop". It was performed once at the 1972 Summer Olympics by Olga Korbut and was immediately banned for being considered too dangerous.

** This only applies to vertebrates, however. Bees can sting *insects* with impunity as their stingers have no problems with exoskeletons. They just get stuck in fleshier victims. Their (lack of) aggression has more complicated evolutionary origins and depends largely on the individual species.

* VideoGame/TenchuStealthAssassins: in Wrath of Heaven and it's Xbox port Return from Darkness, Rikimaru and Ayame are able to learn a technique based off the original games title "Wrath of Heaven", though the technique slightly differs between the two as Rikimaru can only target one enemy who is instantly killed if struck, even boss characters, Ayame on the other hand simply damages all enemies near her in a giant energy thrust, but the one thing this technique has in common with both is that using it reduces your HP to 1 point, so you have to be sure you hit your target/s otherwise your left open to an enemy attack that will all but kill you if you don't have a Ninja Rebirth on hand or can't down a Heatlh Potion quickly enough.

* "VideoGame/TenchuStealthAssassins: in Wrath of Heaven and it's Xbox port Return from Darkness, Rikimaru and Ayame are able to learn a technique based off the original games title "Wrath of Heaven", though the technique slightly differs between the two as Rikimaru can only target one enemy who is instantly killed if struck, even boss characters, Ayame on the other hand simply damages all enemies near her in a giant energy thrust, but the one thing this technique has in common with both is that using it reduces your HP to 1 point, not to mention in Rikimaru's case you have to be sure you hit your target otherwise your left open to an enemy attack that will all but kill you if you don't have a Ninja Rebirth on hand or can't down a Heatlh Potion quickly enough.

* "VideoGame/TenchuStealthAssassins": in Wrath of Heaven and it's Xbox port Return from Darkness, Rikimaru and Ayame are able to learn a technique based off the original games title "Wrath of Heaven", though the technique slightly differs between the two as Rikimaru can only target one enemy who is instantly killed if struck, even boss characters, Ayame on the other hand simply damages all enemies near here in a giant surge of energy, but the one thing this technique has in common with both is that using it reduces your HP to 1 point, not to mention in Rikimaru's case you have to be sure you hit your target otherwise your left open to an enemy attack that will all but kill you if you don't have a Ninja Rebirth on hand or can't down a Heatlh Potion quickly enough.

In more "realistic" examples involving martial arts, a master may teach the principal of a specific attack to a student, but ban them from trying it on an actual person in practice, because it's just too lethal, and even if you were intentionally trying to pull your blows, you might accidentally kill your partner.

** While it's not really forbidden, lightning redirection (a Firebending technique where you internalize lightning and shoot it in another direction) is extremely dangerous, to the point where even firebending masters are reluctant to teach it, because there's no real way to practice it first. First, you have to ''catch'' the lightning, which is just as dangerous as it sounds. While internalized, the lightning must be carefully controlled so it doesn't travel through vital organs. If the technique isn't performed ''perfectly'', then the user takes the full power of the lightning strike anyway, which is almost always fatal. By the end of the series, only three characters know the technique, and only [[OldMaster Iroh]] is skilled enough to avoid the dangers consistently.

** The ''Series/StarTrekTheNextGeneration'' episode "The First Duty" involves a maneuver called the Kolvoord Starburst, which involves five ships flying at each other, then opening their plasma vents and evading at the last moment. Done correctly, their engines ignite the plasma and the resulting trail forms a star with a burst from the center. Done incorrectly, you get one or more exploded ships. The last time it was attempted a century earlier, all five cadets were killed, and Starfleet Academy responded by banning the stunt entirely due to the unacceptable risk. [[spoiler:Turns out it was attempted again, and once again it ended in a crash; four of the cadets managed to get out this time, but there was still one fatality.]]

* ''Manga/FlameOfRecca'': After the Hokage clan are defeated by Oda Nobunaga’s soldiers, desperate to save her infant son, Recca, and to protect the Madogu, Kagero used a forbidden spell to open a time portal and send him into the future, at the cost of her becoming immortal.

* ''Film/KillBill'': The Five Point Palm Exploding Heart technique is the most dangerous fighting technique since it could [[spoiler:slowly-but-surely kill the victims without them realized it]] that [[ArrogantKungFuGuy Pai Mei]] refused to teach it to anyone (including Bill). That’s why, Bill is so surprised upon learning that the Bride is revealed to [[spoiler: be [[TheChosenOne the only one]] who inherits this top secret technique when using this technique to kill him]].

* The "Demon Ball" technique in ''Manhua/BowlingKing''. Its creator injured himself badly attempting to perfect it and was forced to retire from professional bowling.

* Multiple moves in the ''Franchise/{{Pokemon}}'' franchise harm the user (such as [[SuicideAttack Explosion]]), but these moves also tend to be very powerful.
** And then there's the move "Struggle," which is a rather weak move that damages the user by 1/4th of its max HP. Chances are, you're only using it four times before you die. And that's a base case scenario; considering that it's a move that only becomes available when all your other moves are out of PP, odds are it'll do even less than that.
** Focus Punch is extremely powerful but at two costs: 1. It takes one turn to power up, leaving the user open for attack. 2. If your Pokemon is hit while powering up, it "loses focus" and can't attack.
** And, of course, the classic Hyper Beam and all of its variations. It has 150 base power but also renders the user immobile on the next turn.
** There's also Curse (if used by a Ghost type) and Belly Drum, where the user sacrifices half its total HP in order to have the foe lose 1/4 HP every turn or maximize its Attack, respectively. If the user uses the former when they have less than half HP left, they faint; the latter fails when the user is at half HP or less.
** As of Generation V, there's a move called Final Gambit, which causes the user to deal its current HP to the enemy at the cost of fainting.
** [[OverlyLongGag And then]] there's moves like Overheat and Close Combat, which, while powerful cause Stat drops to the user and leave them vulnerable to opposing attacks.

* Multiple moves in the ''Franchise/{{Pokemon}}'' franchise harm the user (such as [[TakingYouWithMe Explosion]]), but these moves also tend to be very powerful.

* In the background lore for ''VideoGame/DiabloIII'', the Wizard character is doing this when he or she expands his/her arsenal to include [[PureEnergy the manipulation of raw mana]] and [[TimeMaster controlling time]], as well as when s/he ignores the normal rules about EquivalentExchange that other casters adhere to in order to prevent magical fallout or corruption. This is why the Wizard is much more destructive than the Sorcerer/ess of the past two games.

* ''WesternAnimation/MiraculousLadybug:'' The Rabbit Miraculous allows its bearer to travel back in time and rewrite history, making it one of the single most powerful Miraculouses. The downside is... well, [[ForWantOfANail you're rewriting history]]. For this reason, the Rabbit is a "hero of last resort", only brought in [[GodzillaThreshold when all other heroes have failed]].