Achilles Heel - Television Tropes & Idioms

"You must punch him in the center of his right buttcheek."

— Doctor Mc Ninja

, The Adventures Of Doctor Mc Ninja

Any seemingly Nigh Invulnerable character (particularly The Dragon) will inevitably have some key weakness that can and will be exploited.

In any show where the main character is superpowered in some way, an Achilles Heel is essentially mandated, otherwise they would never be able to get into any kind of personal peril to drive a story. For example, the Gemini Man's 15-minute limit on invisibility (any more and he dies), or The Greatest American Hero's utter ignorance of the full capabilities of his supersuit.

Aliens and monsters that are Immune To Bullets will usually have a fairly mundane Achilles Heel that only surfaces/gets discovered completely by accident when things look the bleakest. The archetypal example is the Martians from H. G. Wells' War of the Worlds who shrugged off everything the armies of the world could muster, and then died from the common cold.

Other versions and variations of the Achilles Heel include:

Fatal Flaw: A psychological weakness, not a physical vulnerability.
For Massive Damage: For video games, this is the spot the player has to hit.
David Versus Goliath.
Drama Preserving Handicap: A method to give some sort of weakness to a character who normally doesn't have one.
Kryptonite Factor
Oubliette: A prison designed to contain a specific character, often accounting for their weakness.
Why Did It Have To Be Snakes

Examples

Anime

In the (1st) anime version of Full Metal Alchemist, the homunculi are pretty much immortal, but can be killed if one gets anywhere near the remains of the human body they were created from. Also, Alphonse is bound to his armor by his blood seal, and should that be destroyed, he's a goner.
In the manga Of Full Metal Alchemist and the anime Full Metal Alchemist:Brotherhood the homunculi are pretty much immortal, but can be killed if you keep attacking and don't give them time to regenerate and/or their core is destroyed. If it isn't chances are they WILL be back(Take Greed as an example). Alphonse's situation stays the same.
The Zentraedi and Protodeviln of Macross and Macross 7 are both weakened by music - the Zentraedi because they haven't been exposed to "culture" for so long, and the Protodeviln because Basara possesses the Anima Spiritua.
Virtually any character in Get Backers have fantastical abilities but with very heavy handicaps, more often than not forcing the characters to pull near-fatal trump card moves. The best example is one character of the main duo, Mido Ban, who can subject people to dreams with his Jagan (Evil Eye) for exactly one minute in reality, but indefinitely in the dream itself, making it an ultimate twink move. The catch? He can only use it once on a person and three times total a day. Needless to say, a lot of antagonists find ways to avoid this or force him to use his Jagan needlessly until he's helpless.
Death Note's Shinigami, being grim reapers, are practically immortal...with two notable exceptions. First, a Shinigami's lifespan is extended by writing names in a Death Note: if a Shinigami forgets to write names, they will actually run out of time and die. Second is the fact that a Shinigami who intentionally uses their Death Note to protect a human - extending someone's lifespan rather than cutting it short - will die instantly. There are also a number of rules they have to follow while in the human world if they don't want to get on the bad side of the Shinigami King. Also, Ryuk is addicted to apples, and goes through some awkward withdrawal syndromes if he goes for too long without eating any.
In Science Ninja Team Gatchaman, the team's main vehicle, The God Phoenix, has a rather poorly thought out weakness in that all the team's sub-vehicles have to be docked for the God Phoenix's weapons systems to work. While that kind of weakness would make sense to create the plane's Fiery Phoenix effect since it's an exotic weapon system, to have it affect the regular weapons seems too much. Even worse, Galactor learns about this weakness and the visual clues for it and wastes no time to take advantage of it.
Although pretty much almost completely Immune To Bullets, the cyborg assassins of Gunslinger Girl are pretty much vulnerable as any little girl when they are not focused. Furthermore, shooting them in the eyes should be enough to kill them.
Many times on Saint Seiya, more than one character suffers from this. Shiryu's main means of attacking leaves his heart wide open to attacks for a fraction of a second, something a few people notice over the course of the story. Krishna likewise was only defeated when Shiryu struck his hidden "Star Points", and the Pope of Sanctuary's astral projection attacks left his body wide open to attack.
Probably one of the most gag-inducing Achilles Heels in modern media, the Big Bad of Digimon Adventure 02's only weakness was the Power of Dreams.
In one of the earliest episodes of Inuyasha, a human artist gains the power to make his art come to life, and starts creating some of the most horrible creatures imaginable as an army to obliterate his enemies. However, once Inuyasha destroys the artist's inkwell—which actually turns out to be a magic inkwell—he's down and out.
Subverted in Legend of Lemnear. The Big Bad transforms himself into a 50 foot demon cyclops, and the male hero: The warrior of Bronze declares "You may be tough, but I know your weak spot! Your demon eye!" Then through a crazy set of acrobatics, lands on the demons face to plunge a sword into its eye. Only to have his sword shatter on contact. btw: Don't watch the movie, it's terrible
Goku of Dragon Ball survives a bullet and an axe to the head (relatively) unharmed, but if you grab his tail, he'll pretty much pass out. Eventually he trains himself to not be so affected by it.
- Goku and Piccolo themselves exploit this weakness in the battle with Raditz. After that attempt failed, Goku didn't bother going for the weakness again, because he remembered that Saiyans could also manually detach the tail from the body. Attempted against Nappa and Vegeta, although Piccolo finds out rather brutally that the Elites aren't stupid enough to not train that weakness.
Makoto Shishio from Rurouni Kenshin is a very powerful swordsman, but can't fight for more than 15 minutes straight. If he does, he will overheat to death.
Nagi Springfield of Mahou Sensei Negima is described as invincible with no weaknesses. Except for the fact that he's an idiot who needs a cheatsheet to remember spells. He also has trouble pronouncing latin.
- Alternatively, his commerade Eishun is a more serious character who for his strong focus on his training means a lack of human contact, and therefore a difficulty with women. This seems a common trait in Shinmeiryuu swordsman if Setsuna is any indication. Tsukuyomi takes this weakness too far in the other direction.
All Devil Fruit users in One Piece have the common fatal weakness of becoming completely immobile and useless in deep water. Other fruits have more specific weaknesses; for example, Luffy's Gum Gum fruit makes him immune to blunt force, and can only be damaged by being slashed or pierced. On the other side of the coin, Buggy the Clown's fruit makes him immune to being cut, so his weakness is blunt force.
- In perticular, the Logia Fruits, easily the most powerful of all the Devil Fruits, all seem to have a single weakness that negates their great power or their perfect defense. For example; Sir Crocodile, eater of the Sand Sand fruit, becomes solid when wet. And God Enel, eater of the Rumble Rumble fruit, which gives him lighting powers strong enough to destroy the entirety of Skypeia, is made completely helpless when pitted against Luffy, who is made of rubber and doesn't conduct electricity.
The Yato of Gintama have immense physical strength, but are sensitive to the sun and carry around umbrellas (which double as guns, shields (bullet-proof?), and are very durable, used something like swords) to protect themselves during the day. On one occasion a character died from being exposed to the sun only briefly, after years of being underground.

Comic Books

Perhaps the most well-known Achilles Heel is Superman's weakness to kryptonite. He's also perfectly susceptible to magical attacks.
- It's also generally accepted that Superman would lose all of his powers while exposed to red solar radiation, since the yellow sun is the source of his power.
The unstoppable Juggernaut from X-Men is susceptible to a mental attack once his helmet has been removed.
Martian Manhunter (and indeed his species) was, then wasn't, deathly afraid of fire, which did, then didn't, and now does again melt him into a puddle.
The Ultimate Marvel version of Iron Man can't touch anything with his bare skin, even dust, without causing himself excruciating pain—hence the suit.
- So how does he touch the inside of the suit?
  - Beg pardon. Hence all the drinking.
Traditionally, Green Lanterns have had trouble with the color yellow—except the first of them, whose power came from a different source, and was instead vulnerable to wood. Parodied by the parallel-universe "Green Guardsman" in an episode of the Justice League TV series.
The alien symbiotes, from the Marvel Universe, that created such creatures as black-suit Spider-Man, Venom, Carnage, and Toxin, are vulnerable to "sonics"—essentially, extremely loud or high-frequency noises. Extreme heat is also a notably unpleasant weakness of theirs.
Inverted with the supervillain Doomsday. If you kill him, he comes back, immune to what killed him last time (so, if you tossed him into space, he'd come back probably able to survive sudden changes in pressure; if you did it again, he wouldn't need to breathe the next time; and if you did it a third time, he might—eventually—freeze, or burn up, and come back immune to that).
The brilliant, amoral Thanos from the Marvel Universe has a particularly strange weakness: self-defeatism. As Adam Warlock points out in a Hannibal Lecture in The Infinity Gauntlet crossover, he subconsciously knows he doesn't deserve victory, and thus arranges his defeat without realizing it.
- Best. Achilles. Heel. EVER.
Rising Stars features a character completely immune to physical damage. However, he still needs to breathe, and is killed by someone sneaking up behind him and throwing a plastic bag over his head.
- More generally, in the third story arc, it is discovered that the resistance to damage that, by this point, all specials have, does not guard against radiation. Thus, a special who has spent the last 10 years stealing and hiding nuclear weapons gets radiation sickness, and any special can be temporarily weakened by an electromagnetic pulse.
The Gladiator, one of Marvel's many Superman expys, is exactly as powerful as he thinks he is, so he can be defeated by denting his confidence.
Norman Osborne, the current Big Bad of the Marvel Universe, has one rather serious Achilles Heel: he's a nutcase. As Osborne he's a twisted and brilliant Magnificent Bastard — and a sociopath. As the Goblin he's so batshit crazy he makes his Osborn side look well adjusted. As a result, it doesn't take much effort to get a Villainous Breakdown out of him. At one point due to some "nudging" by imprisoned psychics, just being reminded of Spider Man lead to Osborne pacing around in his office naked and ranting. And this is still saner than his Goblin persona.

Film

The mother of all Achilles Heels is the exhaust port on the Death Star in Star Wars, through which an invincible planet-destroying space station can explode into an enormous fireball because of a couple torpedoes from a small one-man fighter spacecraft.
- Admittedly, knocking out its reactor core. Or, given that there was an explosion, instead of the station just going dead, knocking out the reaction controls, started a chain reaction (heh) which destroyed the station.
Possibly the silliest Achilles Heel in film history was in Signs, where the powerful aliens who had been wreaking havoc turned out to have a fatal weakness to... water. Possibly, they shouldn't have invaded a planet two-thirds covered in water without protective suits. Just maybe.
- Which is why some people think they were actually doing some kind of ritual hunt or adulthood rite.
- An especially silly weakness given that H2O is the second most common molecule in the universe, after H2.
- Aliens being vulnerable to water qualifies as its own trope, given the sheer number of times it has been used in sci-fi, especially old short stories. Extra points if someone says, "How ironic, the unstoppable aliens were vulnerable to so common a substance!"
Independence Day. 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.
War Of The Worlds and Horrible Tom Cruise Movie with the Same Name, the aliens are entirely vulnerable to Earth bacteria and viruses. Which actually kinda makes sense. In the way it makes sense for you to be affected by the Tobacco mosaic virus. The idea that aliens would be bothered by our diseases is even less likely than that. (In League Of Extraordinary Gentlemen Volume 2, the virus was specially tailored by Dr Moreau. Yes that Dr Moreau.)
- To be fair, they are trying to stay faithful to source canon, which was written in an age where less was understood about bacteriology.
A blink-and-you'll-miss-it "Achilles Heel" of sorts appears in the Jim Carrey movie Liar Liar, 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—sub-zero temperatures!"
The Wicked Witch of the West's vulnerability to water.
Parodied in Scary Movie 3. The aliens are fighting the group (though just because strangling is how they say hello), when Mahalik decapitates one with a shovel and says:
Mahalik: I found their weakness. They're powerless without their heads!
Also parodied in Harold And Kumar Go To White Castle, during a psychedelic dream sequence.
Officer Palumbo: Bullets! My only weakness! How did you know?
Lampshaded and overdone ad nauseum in 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. 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 time. Everything has to happen on his schedule.
In Attack of the Killer Tomatoes, the titular tomatoes are defeated by playing the fictional artist Ronny Desmond's new hit song "Puberty Love," which causes them to shrink and become vulnerable to crushing.
Similarly, in Tim Burton's Mars Attacks!, the Martian attackers are defeated by playing Slim Whitman's "Indian Love Call," which causes their heads to explode.
Talos the Titan in Jason and the Argonauts has a near-literal version of this trope.
- That's the way it was in the original.

Literature

The name for this trope, and what makes this Older Than Dirt, is the Greek hero Achilles, whose mother, the nymph Thetis, dunked him in the River Styx to make him immortal. However, she wasn't able to dunk the foot she held him with, since as a goddess, she could not bear the touch of the Waters of Styx. Quite naturally, he was killed by a poisoned arrow to the heel, courtesy of the "cowardly" Prince Paris. Incidentally, Achilles is wounded in The Iliad at least once; he just can't die from wounds anywhere else.
- Making him literally, a One Man Army who threatens to kill all the Trojans by himself before the Gods restrain him.
- In some versions, he was her LAST son by a mortal man, and she held him over a fire to burn off his mortality ( a process that had killed his brothers, but he was apparently stronger). She was holding him by his heel. Then his father showed up, pulled him away, and drove Thetis out, preventing her from finishing the process.
- Actually, Homer never mentions Achilles's invulverability, and as noted, Achilles takes a minor wound in the Iliad. The earliest known source to talk about the invulnerable-except-the-heel thing is Statius, writing in the 1st century (900 years after Homer)—a case of Adaptation Decay, perhaps?
Also from Greek myth, the Gigantes were the children of Gaia and only had their supernatural powers when they were touching the ground. Heracles defeated at least one of them by picking him up with one hand and beating him with the other.
- Antaeus is not labeled among the Gigantes. The true Gigantes did have a weakness though. They could only be killed by weapons of a mortal being. Hence, the gods invited Herakles (or perhaps that was the entire point about their affairs with mortal women). Some Gigantes were defeated by gods, but not killed - one is still alive, breathing fire under Etna.
Mythology loves this one. In the Persian epic Shahnameh, the Persian prince Esfandyar bathed in a pool of invincibility, but kept his eyes closed as he submerged himself. When he picks a fight with the hero Rostam, he gets killed by an arrow through his eyeballs.
In the Biblical Book of Judges, Samson loses his Super Strength when Delilah cuts off his long hair. Notice that this is hinted to not be a 100% Achilles Heel. Hot Blooded as he was, Samson had broken all of the other rules God gave him to keep his Super Strength and telling Delilah about his hair (and how he was consecrated to God) was figuratively the last straw.
Leto Atreides II, the titular God Emperor of Dune, who combines his body with a sandworm to extend his life by thousands of years and gain immunity to almost every form of physical damage, also inherits the sandworms' vulnerability to water.
When Balder (of Norse Mythology) 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 Balder. 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 "Let's throw things at Balder" into their favorite party game, Loki (who was jealous of the attention accorded Balder) tricked the blind Hoder into shooting a Mistletoe arrow at Balder...
In the Chronicles of Chrestomanci by Diana Wynne Jones, the Chrestomanci are powerfully magic characters who are nearly invincible due to their powers, and their nine lives. However, every Chrestomanci has one particular weakness.
In the German myth of Das Nibelungenlied, the hero Siegfried bathes in the blood of the dragon, Fafnir, after he's slain it, and becomes invincible as a result. However, a leaf had stuck to his shoulder, and thus left a small spot there untouched by the blood... and yes, the similarities between him and Achilles have been noted before.
In David Eddings' The Belgariad, it appears the Achilles Heel of the ancient and evil god Torak is to tell him nobody loves him. As everything he'd done through his existence was to force people to love him, this throws him into an Unstoppable Rage... which causes him to drop his guard. Cue impalement.
Although it can vary, werewolves are typically weak to silver, touching it causes severe burning.
In The Lord Of The Rings, Sauron is incredibly tough, but if the One Ring he created is thrown into Mount Doom, he will lose all of his power, so that all he becomes is a little formless evil spirit incapable of affecting anything around him forever. Arguably, that's worse...
While we're on the subject of Tolkien, there's Smaug, from The Hobbit. With his armoured scales he is well nigh invulnerable - except for one missing scale in his belly, unknown even by Smaug himself until Bilbo discovers it.
- An unarmored spot or weakly-armored belly is a common feature of many dragons in Western legend. (See "Fafnir" example, above.)
Generally a Soul Jar is the weakness for anyone who uses it.
It's stated in the Harry Potter series that Voldemort's weakness is his inability to love.
- And his horcruxes.
One of the 'Demon Headmaster' books featured a super logical computer which was defeated by all the children in the world yelling pointless anti-logic.
In Dan Simmons' Illium and Olympos the Trojan war is being deliberately recreated. Part of this involves Achilles being given a sort of quantum invulnerability that ensures he will only every be hurt by an arrow intentionally fired at his heel by Paris, which probably takes the cake for most specific and most inevitable Achilles Heel.
Fairy folk in the Artemis Fowl series are all susceptible to animal fat. Being exposed to animal fat will suck out all of their magic.

Live Action TV

In Angel, where Angelus figures out the Beast's weakness rather cleverly:
"I mean, look at this guy, hm? Pretty much the only thing that could do damage to that thick, stony hide...is himself. Or, maybe, I don't know, a piece of himself."
Doctor Who does this a lot.
- Cybermen were given an Achilles Heel in the story "Revenge of the Cybermen": gold dust would asphyxiate them. This was not a tremendously damning weakness, since gold is neither common nor easy to form into an effective weapon. In "Revenge of the Cybermen", the cybermen were almost indestructible even on a planet made entirely of gold, because the locals didn't have the technology to make an effective delivery system for the gold. As the series progressed, gold was promoted to kryptonite status: in "Earthshock", the Doctor injures, but does not incapacitate, a cyberman by grinding a gold badge into its chest, but by "Silver Nemesis", cybermen can be killed by lobbing gold coins at them, or shooting gold-tipped arrows. Gold tipped arrows are very effective against cybermen, but, of course, totally ineffective against anything else. It is sometimes joked that had the original series gone on, it would eventually have been possible to destroy a cyber-war-fleet just by saying "gold" at them. While not mentioned in the new series, a fake website connected to it hints that the Cybermen seen in "Rise of the Cybermen" and later episodes had the gold weakness worked out in the prototype stage. It was showed on a computer screen in that episode that the weakness had been worked out.
- The Sontaran's 'probic vent'. "Back of the Neck!" Of course bullets work perfectly well too...
- The Slitheen, being composed largely of calcium, can be killed with acetic acid. Similar to the Signs aliens, this makes them look not all that bright for repeatedly invading England, the land of putting vinegar on everything.
- The Daleks were originally vulnerable to turning off the static electricity.
- The Macra were helpless without their special gas (which made one wonder how they managed to force humans to start making it in the first place).
- The Ice Warriors are vulnerable to (what else?) heat.
- The deadly sea weed of The Fury from the Deep were vulnerable to Victoria screaming (luckily, she was good at it).
- In addition to the gold allergy mentioned above, the Cybermen have been vulnerable to emotions in several appearances, and solvents in others.
- Autons are also vulnerable to solvents and, later, anti-plastic... which sounds a lot like solvents, but now with new, improved, cooler name!
- The "Seeds of Death" are vulnerable to water, WATER! (Not to be confused with the "Seeds of Doom", which are vulnerable primarily to large explosions, which doesn't qualify for this trope.)
- The evil computer in the Green Death was vulnerable to logical dilemmas.
- Mandragora energy is vulnerable to being conducted away.
- The Fendahleen are vulnerable to salt.
- The giant octopus Kroll was vulnerable to... a small stick. Okay, a special stick.
- The Mara is (are?) vulnerable to mirrors and happy thoughts.
- The Sea Devils and Silurians are helpfully vulnerable to a deadly gas which is blatantly introduced at the start of "Warriors of the Deep", then conveniently forgotten about until the climax.
- The Destroyer in "Battlefield" is vulnerable to silver.
- Fenric is vulnerable to puzzles.
- The Master leaves himself vulnerable to happy thoughts in "Last of the Time Lords". In addition, his biggest weakness throughout the series is... the Doctor, the one person he's never fully understood. (One episode of the classic series shows that his worst fear is a room full of the Doctor, laughing at him.)
In Six Million Dollar Man and The Bionic Woman, extreme cold could make the bionic heroes' parts stop working until they warmed back up.
In Heroes, Claire Bennet has a Wolverine-class healing factor that can repair her body to brand new after taking the unrealistically extreme amount of punishment that always comes her way. However, if an object is stabbed into a certain spot in the back of her head, she's rendered "dead" until it's removed, and the same goes for anyone who copies her powers. It's implied (and confirmed in an alternate future episode) that if this part of her brain was removed or destroyed, she would die permanently.
Sheriff Lucas Buck's vulnerability in American Gothic is his third eye—if stabbed there, he could be killed. What makes this a particularly egregious example is that not only is there no indication of this vulnerability until the next to the last episode of the show, but what could have been a very cool mythologically resonant plot point is instead wasted twice over: the person who reveals and exploits this weakness is a throwaway character we'd never met until the previous episode and the stabbing doesn't even take, since Buck is revealed alive in his grave at the end of the episode.
In Star Trek DS 9, Founders are almost absolutely immune to physical damage, vulnerable to BIG amounts of radiation or phaser weapons... and can be killed by specific virus.
- They also have to go into liquid form for 8 hours a day, much like humans need to sleep. In one episode, Odo was prevented from doing so, and started physically falling apart as a result.
Although not one related to the villain itself, the Goa'uld of Stargate SG-1 have force shields that can be bypassed by slower-moving objects. (Bullets won't work, but a thrown knife will). Later, the Replicators can only be destroyed with projectile weapons. Yes, their only weakness is getting shot. It makes sense in the show.
The Borg are near unstoppable forces of nature that assimilate and adapt to everything they come across, but Star Trek Voyager reasoned that if they can't assimilate it then they can't adapt to it, which is why they were so vulnerable to Species 8472. The Voyager crew, on the other hand, used scientific investigation and creativity, which allowed them to design a weapon to use against 8472.

Tabletop Games

Many Dungeons and Dragons monsters have specific weaknesses that either do more damage than normal, or are necessary to even be able to kill them. The most famous is arguably the troll, which in most editions can't be killed with just standard weapons, but that also needs to be burned with acid or fire for it to permanently die. Unconventional tactics can also exploit certain weaknesses, or at least find other ways to kill them.
- Also included are demons/devils vulnerability to certain metals such as cold iron and silver
Virtually any named enemy in Deadlands will be Nigh Invulnerable, except for one weakness somehow obscurely related to its past. The list goes on: Stone, Raven, the Bishop, prominent Whateleys, Grimme, Death, War, Pestilence, Famine ... In fact, it's so common that one of the most coveted abilities of arcane characters is the rare ability to intuit these weaknesses. (That's part of why the Bad Ass Normal posse keeps the bookworms around.)
The Vulnerablity disadvantage in GURPS gives characters an attack that does multiplied damage to them. Skeletons are especially vulnerable to crushing attacks, fairies to iron, werewolves to silver, ice elementals to heat and so on.

Video Games

Just about any glowing spot, on any boss, in any video game. Sometimes just does extra damage if hit, but is often (in Platformers especially) the only place where the boss is not Nigh Invulnerable.
- This is particularly anvilicious in Shadow of the Colossus, in this troper's opinion.
In many First Person Shooter games, enemies may have strong body armor, but can be killed faster by shooting them in the head (i.e. headshots).
- For example: House Of The Dead, where not only do headshots take down enemies faster, but each boss has a specific weakpoint, and cannot be damaged (or only take minimal damage) if shot anywhere else. The best one is the one with a huge gaping hole in it's chest that opens to reveal it's heart every time it beats (How...not easy...).
The superhero MMO City Of Heroes balances all classes and powersets by giving them strengths and weakness, but only the Peacebringers and Warshades have a specific crippling weakness, Quantum Energy damage, which only NPCs with Quantum Weapons can deal. The problem was that the developers overdid it and made the weapons available to every enemy group in the game, essentially distributing kryptonite bullets, and it many cases it was powerful enough to kill the player in a single hit. As this was a major gripe about the two classes, eventually the developers responded by reducing the effects of the weapons to make it simply a danger rather than an overwhelmingly crippling threat.
- Furthermore, many defensive sets have Achilles Heels in the form of damage types they offer only minimum protection against. Ice Armor melts under fire damage, Fiery Aura is susceptible to cold, Dark Armor has only minor protection against energy and so on. Only two or three armors in the game offer appreciable protection against psychic attacks.
- Ironically the Quantum Energy problem almost exactly mirrors a problem encountered by Superman.
Legend of Zelda. In this case, it's nearly always the eye or another insufferably obvious 'weak point'.
- Usually an eye in an odd part of their body.
- Ganon/Ganondorf usually has a spot on his chest or his weakness is his tail. And of course, the Master Sword also counts.
Arcueid Brunestud, and presumably all the True Ancestors from Tsukihime. Normally Arc in particular is all powerful, but thanks to the protagonist Shiki cutting her to pieces early on in the game she's usually pretty weak. We finally see her true abilities at the end of the Ciel route, when she goes batshit crazy after finding out that Shiki has chosen Ciel over her. Shiki only wins when he remembers that True Ancestors get their power from the earth itself, so he kills the earth beneath her to cut her away from her power source.
In the later editions of the Resident Evil series, bosses began to show certain specific weak points. For example, all of the Uroboros creatures in RE5 have glowing weak points which can be shot to expose bulbous body parts that can then be targeted to kill the creature itself.
Gilgamesh in Fate Stay Night has the two most broken Noble Phantasms in the game. One of them is beamspamming Noble Phantasms and the other is some spinny drill sword thing that absolutely dominates Excalibur. Oh and he can use them both all he likes. Weakness? He's an Archer, not a swordsman, so all he can do with those swords is beamspamming them instead of using them properly. Much more importantly, he has an ego so larger that it's even bigger than his ego. Wait. But anyway, he never takes any fight that he's in seriously until he's in mortal peril. Or pieces.

Webcomics

In Sluggy Freelance, Aylee's crab-like transformation (actually a clone of Aylee) is nearly invincible. Her shell can take just about anything the characters can throw at her, but she can be hurt along her extendable neck.
- Horribus is also only vulnerable on certain parts of his body. Even when Torg uses a magic, kill-anything sword, he can still only take Horribus down by either decapitating him or stabbing him right through his soul (located roughly in the center of his chest).
Frans Rayner in The Adventures Of Dr Mc Ninja is vulnerable on only one place on his body (his right butt cheek). However, the protagonist (who witnessed his defeat as a boy) strikes the same place 25 years later and fails... Rayner had moved it to his left eyebrow.
From Eight Bit Theatre, "A spear? Through my brain? My...only...weakness..!
- Parodied similarly much earlier on when Black Mage is left to deal with a zombie orc. After an explosion propels him back in front of the team:
  Black Mage: I found out what zombies are weak against.
  Red Mage: Oh?
  Black Mage: Point blank annihilation.

Western Animation

You'd think, with the Omnitrix making him able to transform into an alien of his choice at will, that Ben Tennyson of Ben 10 would be pretty much invincible. He isn't though, for several reasons, including but by no means limited to: the seemingly 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 ten-year-old boy.
When Alex O'Hirn becomes the superstrong Rhino in The Spectacular Spider Man, he goes on a destructive rampage and appears completely unstoppable. His Achilles Heel turns out to be the same thing that makes him so tough: Because his suit is completely impenetrable, he can only perspire through his exposed face. Spider-Man is able to defeat him by trapping him in a steam-tunnel in the sewers, which causes the giant thug to overheat and collapse.
In Justice League, the forge god Hephaestus says that all of his creations are given one weakness so no one can become all-powerful. When Wonder Woman asked him what Ares' Humongous Mecha is vulnerable to, he doesn't tell her, saying she wouldn't want him going around telling the weakness he'd placed in her items. She does not look happy the revelation that she has any.
In Avatar The Last Airbender, Firebenders have no powers during the solar eclipse. However the good guys launch a daring but small assault on the capital of the Fire Nation during the eclipse and they are unable to find the Firelord, as he is wisely in an underground bunker hidden far away from them, and the majority of good guys are captured, having failed to accomplish anything. Likewise, Waterbenders are powerless without a source of water close by, although sweat has been used, water was drawn from the moisture in the air, and with the full moon behind them they can also bend blood (there are moral implications to that though). It would be expected that tears and saliva could be used too. Earthbenders are powerless if separated from earth, sand or stone, unless you can bend metal, like Toph. The only Avatar race that's mostly invulnerable are the Airbenders since air is always around. And yet they were the ones that ended up getting wiped out. Go figure.
- Possibly justified: the Airbenders were almost all peaceful nomads, so the Fire Nation took them out first, possibly because they were the most versatile in their bending.
- Or it could have something to do with the fact that they knew the next Avatar in the cycle would be born an airbender...
  - or maybe both
- It was explained in the first season that airbenders have unlimited source to their element, but since it is air they don't have much power behind it, unlike waterbnding or earthbending. Aang was once shackled with chains and no amount of airbending could break them.
The concept was portrayed hilariously in the movie Fry and Leela watch in the Futurama episode "Fear of a Bot Planet". Taking place on a planet where humans are considered monsters, and the citizens are all robots:
Robot Army Officer: "How ironic; the Human was immune to our most powerful magnetic fields, yet, was vulnerable to a harmless sharpened stick."
- Also lampshaded in Bender's Big Score, during the battle against the Scammers' fleet of gold-plated Death Stars. One of them is destroyed in classic "fly-in-and-blow-it-up-from-the-inside" style, with access being gained via a hatch labelled the Achilles Port. By Al Gore of all people.
The members of the Sushi Pack lose their powers and strength if they're exposed to heat. They also tend to announce this whenever it happens. "Heat! Our only weakness!"
In a Simpsons Harry Potter themed Treehouse of Horror Montymort's (Mr.Burns) only weakness was his enchanted shin.
The Omnodroid in The Incredibles could only be harmed by its own weapons.
From Gargoyles, the Archmage during the "Avalon" three-parter has gone from a formidable but very overconfident mortal sorcerer to a demigod powerful enough to command the allegiance of three of the most powerful Children of Oberon in the series. The catch? He can only control his incredible new powers by using the Eye of Odin, and when Goliath manages to get it away from him... well, let's just say he sufferes Power Incontinence so bad it kills him.