History Main / AchillesHeel

* In the German poem the ''Literature/{{Nibelungenlied}}'', the hero Siegfried [[BloodBath bathes in the blood of a dragon]] after he's slain it, and becomes invincible as a result. However, a leaf had stuck to his shoulder, and thus left a spot there untouched by the blood.

* When Baldr of Myth/NorseMythology started dreaming of his own death, his mother went around to every single thing in existence and made them swear an oath to never harm Baldr. Presto, invulnerable god, right? Not quite: she forgot to ask mistletoe, since it seemed too small and shriveled to be a threat. When the rest of the pantheon decided to make [[WhatCouldPossiblyGoWrong "Let's throw things at Baldr"]] into their favorite party game, Loki (who was [[GreenEyedMonster jealous]] of the attention accorded Baldr) tricked the blind Höðr into shooting a mistletoe arrow at Baldr. This killed Baldr, and Loki's refusal to weep for him along with the other gods to bring him back would [[MoralEventHorizon make him an enemy of the other gods]] and ultimately lead to Ragnarök.

* When Baldr of Myth/NorseMythology started dreaming of his own death, his mother went around to every single thing in existence and made them swear an oath to never harm Baldr. Presto, invulnerable god, right? Not quite: she forgot to ask mistletoe, since it seemed too small and shriveled to be a threat. When the rest of the pantheon decided to make [[WhatCouldPossiblyGoWrong "Let's throw things at Baldr"]] into their favorite party game, Loki (who was [[GreenEyedMonster jealous]] of the attention accorded Baldr) tricked the blind Höðr into shooting a mistletoe arrow at Baldr.

* You'd think, with the [[BlackBox Omnitrix]] making him able to transform into an alien of his choice at will, that Ben Tennyson of ''WesternAnimation/Ben10'' would be invincible. He isn't for several reasons, including but by no means limited to: the random time limit (possibly based on some measure of energy expenditure, as the Omnitrix generally needs to "recharge" for an equally random amount of time afterward), the Omnitrix's glitches turning him into an alien other than the one he chose, his own lack of knowledge of the forms hidden in the Omnitrix and the full extent of each one's powers, and, perhaps most dangerously, having the mindset of a [[KidHero ten-year-old boy]].

* ''WesternAnimation/RickAndMorty'': Rick Sanchez's portal gun. If it gets lost, stolen, or broken, Rick (and usually Morty along with him) will be stranded in that universe until he can construct a replacement. Fortunately, he's always smart enough to do so, even from scratch.
* Aku from ''WesternAnimation/SamuraiJack'' was spawned from a powerful EldritchAbomination before time began. This creature was weak to divine magic, and the weakness carried over to Aku. Jack's sword was forged under supervision of the gods that destroyed the monster that Aku spawned from, and said sword is the only human weapon capable of hurting him. In "[[Recap/SamuraiJackS1E12JackAndTheGangsters Jack and the Gangsters]]", he's shown having extreme difficulty in defeating a water goddess, and the golems spawned by her had successfully kept him away for some time. Even normal magic seems to do more against him than most anything else, as the Scotsman's Celtic magic from his sword [[spoiler:and his ghost form]] are capable of warding him and his attacks off.

** Parodied in one episode, in which Homer is bribed with a cake and he laments that Marge knows his one weakness: that he's weak.

* ''WesternAnimation/TotalDrama'': Alejandro is a villainous [[TheAce Ace]], being ruthlessly clever, charismatic, and having an absurd amount of talents. The only types of challenges he has no chance in are the ones that involve [[MasochistsMeal disgusting]] [[ForeignQueasine foods]], which he throws right up at the first taste.

* The Omnidroid in ''WesternAnimation/TheIncredibles1'' can only be harmed by its own weapons.

** Trolls in most editions can't be killed with just standard weapons, but need to be burned with acid or fire to permanently die.

* * ''VideoGame/BlueArchive'': Subverted. The story makes a point that destroying a student's halo is essentially the only feasible way of killing a student with brute force... but their halos are confirmed to be intangible. It's noted that any method to "break a halo" is not too different from a method to kill (essentially making it an [[DeadlyEuphemism euphemism]] of sort in most cases), and when the existence of a bomb that could specifically destroy the halo is revealed, it is treated as almost otherworldly technology that's unheard of in Kivotos.

** Unlike most characters, Adam Tarus has a Semblance that requires him to channel it through a weapon. He needs a bladed weapon to [[EnergyAbsorption absorb]] and [[CatchAndReturn release]] kinetic energy. If he's disarmed, his Semblance is effectively disabled.

* ''WebAnimation/{{RWBY}}'': Cinder's greatest physical asset is simultaneously her greatest weakness. Her [[PowerParasite ability to steal]] the [[ElementalPowers power of the Maidens]] comes from the Grimm parasite that Salem implanted into her. As such, Cinder shares the same weakness all Grimm have to the power of the [[MagicalEye Silver Eyes]]. [[spoiler:It is for this reason that series protagonist Ruby Rose is her most [[ItsPersonal personal adversary]]; Ruby's first use of [[LightEmUp this power]] destroys Cinder's eye and arm, leaving her with a permanently scarred face; she has a replacement Grimm arm that continues to allow her to absorb Maiden powers.]]

** Gladiator, one of Marvel's many ComicBook/{{Superman}} {{Expy}}'s and the leader of the Shi'ar Imperial Guard is exactly as powerful as he thinks he is, so he can be defeated by denting his confidence. The typical method is for a character to use trickery to make Gladiator think they did a NoSell, then clobber him when his disbelief saps his strength.

* In the ''Franchise/DCExtendedUniverse'':

* Smaug's Achilles Heel in the live-action adaptation of ''Film/TheHobbit'' is again adapted to a gap in his scales (made when Bard's ancestor tried to shoot him down when he first attacked Erebor -- he broke off one of the scales, exposing the flesh underneath); and his natural hide is otherwise impenetrable all over.
* ''Film/IAmMother''. The Woman who enters the bunker tries shooting Mother to no apparent effect, but Mother later says the bullet barely missed her CPU. Subverted when this ChekhovsGun is about to be fired in the final act [[spoiler:and Mother reveals that destroying her CPU will do no good, as she and all the other droids are just remote drones controlled by a HiveMind ArtificialIntelligence]].
* ''Film/IndependenceDay''. Not only is the alien mothership compatible with Mac OS, but despite millions of years of technological advancement, they don't have even the most rudimentary form of a firewall. It's possible that in their [[HiveMind culture]], software hacking was unheard of. The flying saucers are also weak to jets crashing into their giant death rays.

* A blink-and-you'll-miss-it "Achilles Heel" appears in the Creator/JimCarrey movie ''Film/LiarLiar'', where, faced with the prospect of "doing The Claw to [his ex-wife]", main character Fletcher Reed says, "You've found The Claw's only weakness -- [[IceQueen sub-zero]] temperatures!"
* In Tim Burton's ''Film/MarsAttacks'', the Martian attackers are defeated by playing Slim Whitman's "Indian Love Call", which causes their heads to explode. As a second weakness, they cannot survive on Earth without their helmets and will die if they are removed or broken.
* {{Lampshade|Hanging}}d and overdone ad nauseum in ''Film/{{Mindhunters}}''. The plot of the movie rests on a FBI profiler killer killing other FBI profilers by presenting them in situations where they will have to fall for traps he's devised, because said trap is their weakness. [[spoiler:In the end, he dies by getting shot in the head, causing LL Cool J's character to quip "I guess we found out his weakness. Bullets."]] However, the killer's true Achilles Heel is [[spoiler:time. Everything has to happen on his schedule.]]
* Franchise/MonsterVerse:

* Possibly the silliest Achilles Heel in film history is in ''Film/{{Signs}}'', where the powerful aliens who have been wreaking havoc turn out to have a fatal weakness to ... [[KillItWithWater water]]. They shouldn't have [[TooDumbToLive invaded a planet two-thirds covered in water]] without protective suits. On the other hand, the movie hints that the "aliens" are actually demons and that that "water" is actually holy water, which would justify the water weakness.
* ''Franchise/StarWars'' example:
** One of the best known is the exhaust port on the Death Star in ''Film/ANewHope'', through which an invincible planet-destroying space station can [[EarthShatteringKaboom explode into an enormous fireball]] because a couple of torpedoes from a small one-man fighter spacecraft hit its reactor and caused a chain-reaction explosion. Justified due to the simple fact that the exhaust port is extremely small (only two meters wide) and throws ''out'' exhaust, meaning that the shot is considered impossible until Luke (who is a Force sensitive) somehow manages to do it.\\\
In the old EU, it's made the clear the Emperor was ''pissed'' that there was such a flaw and had the designer repeatedly killed, brought back to life, and then killed again before putting him to work on a perfected design. The second Death Star attempts to avoid this, by instead having lots of much smaller exhaust ports, too small to shoot into. Luckily, the heroes still have an Achilles Heel to exploit, because Death Star II is only about 70% complete when they attack, which includes holes wide enough for them to fly right up inside the main reactor and torpedo it.\\\
In the new continuity, ''Film/RogueOne'' explains that [[spoiler:the flaw was deliberately added and laboriously hidden by a Rebel sympathizer, who was also the one who fed them the information they would need to exploit it. The sympathizer knew that the Empire would eventually build a perfect Death Star even without his engineering prowess (something they would later do in ''Film/ReturnOfTheJedi''), so he accepted their [[AnOfferYouCantRefuse "offer"]] to join the Death Star's engineering team in order to plant this flaw and sabotage them.]]
** [=AT-ATs=] in ''Film/TheEmpireStrikesBack'' are massive {{Spider Tank}}s with heavy firepower and enough armour to [[NoSell not even notice when they're hit with blaster cannon fire]]. Aside from being hit by anti-starship weapons (which aren't normally used on a planet precisely because they're too powerful), there're four ways to take them down: the "neck" with the weapons and the cockpit is relatively unarmored, and concentrated fire will severe the vehicle from its guidance system; the armour, while tough, isn't so effective against a large projectile at high speed such as a [[RammingAlwaysWorks kamikaze airspeeder]]; as they move through legs, a tow cable may be used to "trip" them; and finally, their armour can't resist lightsabers (that, to be fair, cut through pretty much everything), and Luke takes one down by opening a hole and throwing a bomb inside.

* In ''Film/TheWarOfTheWorlds1953'', the aliens are vulnerable to Earth bacteria and viruses. While new beings likely wouldn't be vulnerable to earth's viruses, bacteria would be able to wipe out any species without an adapted (or adequate) immune system. This is because of the different ways that bacteria and viruses work. While it's stated to be the common cold in the movie, it could just be a "sinus infection" (bacterial). Any alien species moving to a different planet would be highly vulnerable to any and all new bacteria. This is a case of ScienceMarchesOn, since the movie came out three years before the cause of the common cold was discovered. In ''ComicBook/TheLeagueOfExtraordinaryGentlemen'' Volume 2, the virus was specially tailored by Dr. Moreau. Yes ''[[Literature/TheIslandOfDoctorMoreau that]]'' Dr. Moreau.

* Generally, a SoulJar is '''the''' weakness for anyone who uses it.
* Although it can vary, [[OurWerewolvesAreDifferent werewolves]] are typically weak to silver; touching it causes severe burning.

* In Creator/DavidEddings' ''Literature/TheBelgariad'', it appears that the Achilles Heel of the [[BigBad ancient and evil god Torak]] is to tell him that nobody loves him. As everything he's done through his existence was to force people to love him, this throws him into an UnstoppableRage... which causes him to drop his guard. Cue impalement.

* In the ''Literature/{{Chrestomanci}}'' series by Creator/DianaWynneJones, the Chrestomanci are powerfully magic characters who are nearly invincible due to their powers, [[spoiler:and their nine lives]]. However, every Chrestomanci has one particular weakness.
* One of ''Literature/TheDemonHeadmaster'' books features a super logical computer which is defeated by all the children in the world yelling pointless anti-logic.

* In Creator/AaronAllston's ''Literature/GalateaIn2D'', Red comes from a painting of Achilles and has the heel.

* In ''[[Literature/TheWheelOfTime A Memory of Light]]'', [[spoiler:Padan Fain, aka Mordeth, aka Shaisam has become a borderline EldritchAbomination with a host of unnatural powers and a small army of the undead at his disposal, and is a genuine threat to the forces of both good and evil -- not bad for the snivelling PunchClockVillain he started out as. However, his original human body, which is at the heart of the shifting cloud of [[FogOfDoom white killer mist]] that in many ways is ''really'' him, remains mortal. When [[BadassNormal Mat]] kills said human body, the entire horrible entity is dissipated.]]

* Even though it features the trope namer, ''Literature/SongOfAchilles'' does not include the literal heel as Achilles's one weakness. Metaphorically it's actually his {{Pride}}, and he dies by being shot in the heart by an arrow shot by Paris and guided by Apollo. This is actually consistent with the original version by Creator/{{Homer}}, since the bit with the heel was added several centuries later.

* ''Literature/TheWarOfTheWorlds1898'' involves aliens who come to invade the Earth, and the governments of the world are unable to stop them until they get defeated by ordinary bacteria, to which the aliens' immune system, having never been exposed to them, are extremely vulnerable.
* In ''[[Literature/ThoseThatWake What We Become]]'', hired goon Castillo has a weak knee.

* ''TabletopGame/{{Anathema}}'': It is literally impossible for a human to kill a shroud. They can fly as fast as a commercial jet, move through walls, become invisible, and have magic powers, but they can be killed by other shrouds and will be utterly destroyed if their will drops to 0.

* In ''Film/{{Highlander}}'', the immortal warriors can recover from any kind of injury perfectly, but their necks are uniquely vulnerable. Kurgan is left with a nasty throat scar and a [[GutturalGrowler permanently raspy voice]] as a result of a strike at the neck from Ramirez that still hasn't healed after nearly four centuries.

* ''TabletopGame/{{Battletech}}'': Achilles' Heels are a feature in several 'Mech designs, who have sections they absolutely ''do not'' want to take SubsystemDamage to (in addition to their cockpit/head, [[BoomHeadshot which no 'Mech likes taking damage to]]). Most commonly this is because that's where they store [[MadeOfExplodium all their explosive ammunition]]. The two most common pitfalls in ammo storage is to store it in the centre torso (where there are lots of components that can take a CriticalHit, but if the ammunition gets hit it will score a OneHitKill on the entire 'Mech), or in an otherwise empty section that has nothing but ammunition (which means a CriticalHit will automatically set off an ammo explosion). The WHM-6R ''Warhammer'' is a classic example of the former, carrying up to 400 damage worth of machine gun ammunition in its centre torso, while the MAD-3R ''Marauder'' is a classic example of the latter, with its left torso being entirely empty save for 100 damage worth of autocannon/5 ammunition.