This is when someone seems to be doing absolutely great in a fight — no enemy even so much as grazes them— only to suddenly get an unlucky stab/shot get through their seemingly impregnable defenses. And just like a Dutch dam, one little leak (of blood) is all it takes for their whole defense to come down hard and let every enemy Mook land dozens more attacks. Before long they're overwhelmed and either captured, KO'd or killed.
Normally the defense-breaking attack was already lethal and everything else was just icing on the cake. Sometimes it's a lucky hit that trips them up. Usually they still manage to kill a few dozen more enemies before being felled by injuries. This can be caused by enemies (either intentionally or through luck) exploiting the character's Achilles' Heel (whether Attack Its Weak Point, Kryptonite Factor or other things).
A couple of subversions are to have the character survive the onslaught and show up some time later, have the lucky hit cause a Minor Injury Overreaction, or become akin to a wrecking ball pin-cushion that's more destructive for having been put so close to death (without actually dying). An aversion is to merely have them take grazing damage throughout, or have lethal attacks kill instantly or post battle.
A side-wide version of this trope that replaces the lone hero with a Mook Maker structure is a common occurrence in Real-Time Strategy games, especially in Multiplayer Online Battle Arena types. Units can keep slaughtering each other for all eternity, but losing a single unit-producing structure almost guarantees that side's doom as their defenses are swamped (unless they manage to balance out the numbers).
Very much Truth in Television, as injuries can be debilitating or crippling even without inflicting significant damage otherwise. For example, some sword arts involve shallow slices to the arms or hands which might not sever the limb, but cutting the muscle or tendon will prevent it from properly flexing, thus reducing its functionality and making a more lethal follow-up much easier to land.
See also Keystone Army. See also/compare Dog Pile of Doom, where the mooks simply jump on the hero. Contrast Minor Injury Overreaction. Compare One-Hit Point Wonder. Compare Injured Vulnerability, Monster Threat Expiration, Stun Lock and Not So Invincible After All.
- Dragon Ball Super: During the final showdown of the Future Trunks Saga, the newly-created Merged Zamasu initially appears to be unstoppable, shrugging off everything Goku, Vegeta, and Future Trunks throw at him... and then Goku manages to reflect his Sphere of Destruction attack back at him, which reduces the entire right side of his face to purple goo. As it turns out, Future Zamasu's Complete Immortality has been compromised by his fusing with the mortal Goku Black; thus, he's no longer completely immortal and can be killed.
- At the end of the Marvel Comics' Onslaught crisis the Hulk hits Onslaught so hard his armor is wrecked, which is more than anyone else could do. This is all the other heroes need to finally get through to defeat him.
- This is basically the whole deal with Gladiator, the leader of the Shi'Ar Imperial Guard in the Cosmic segment of the Marvel Universe. His powers are fueled by self-confidence, so he's effectively invulnerable until somebody somehow manages to land one he feels. From there it's all downhill, usually rapidly.
- The Matrix Reloaded. For most of the "Burly Brawl" fight between Neo and Agent Smith, Neo does quite well, not defeating the Smiths but holding his own. Near the end, as Neo is jumping from one Smith to the other, a Smith jumps out of nowhere and takes him down, allowing all of the other Smiths to dogpile on him. Because he's the One, he throws them off and escapes, but it's a near thing.
- When Boromir is fending off the Uruk-Hai in The Lord of the Rings: The Fellowship of the Ring he is killing them non-stop with nary a lucky hit, until their leader, Lurtz, manages to snipe him from afar. Justified in that Lurtz is shown to be considerably smarter than the other orcs. It's almost a subversion though because Boromir rallies pretty quickly. He doesn't go down until Lurtz puts TWO more arrows in him.
- Mars Attacks! Near the end Byron Williams faces off against a horde of Martians in hand to hand combat so the others can escape. He repeatedly punches the Martians until one of them jumps on his back and prevents him from defending himself, whereupon the rest swarm over him and take him down.
- District 9. The Prawn Mini-Mecha appears to be Immune to Bullets until it gets hit with a BFG (specifically, a South African 30mm anti-tank rifle), and from that point onwards it gets more and more easily damaged until it gets shut down by a simple 9mm pistol. Wikus still gets his fair amount of mileage out of it, though.
- As the page quote bears out, the Jedi can easily deflect blaster bolts up to a certain point, which is what Palpatine uses to wipe them out with Order 66 in Revenge of the Sith; the Jedi not taken completely by surprise in the first place are unable to ward off such concentrated blaster fire and are quickly felled once a single bolt gets through their defense.
- In Rurouni Kenshin: The Legend Ends, Kenshin and Sojiro's rematch has them fairly equal at first until Kenshin manages to get in a hit on Sojiro's legs, causing him to slow. From then on Kenshin manages to land more and still more hits on Sojiro, until he can use his Finishing Move.
- In Godzilla: Final Wars, the Controller tosses Ozaki around like a ragdoll until Ozaki manages to stun him with a punch to the throat. Then Ozaki turns the tables and beats him down.
- Rocky IV: Ivan Drago completely curb-stomps and kills Apollo in the opening, and when he and Rocky first fight, it initially shapes up to be the same until the second round, where Rocky lands a punch that cuts Drago below the left eye; Drago is left visibly shaken by the injury, and from there on out, the fight is more even.
- Discussed in Barbara Hambly's Star Wars Expanded Universe novel Children of the Jedi. As Jedi-turned-computer entity Callista notes to Luke, a Jedi may be able to fend off blasterfire for a while, but once one mook gets lucky, more mooks will get lucky. That's how Callista died the first time around.
- The Ciaphas Cain novel "The Last Ditch" has a big Tyranid monster able to shrug off lasgun and bolt pistol fire until an air-to-surface missile breaches its carapace, allowing the squad to aim for the breach and bring it down.
- The second time Cain fights a Chaos Marine in The Traitor's Hand, he takes advantage of prior battle damage to the Marine's armor, and shoves his chainsword through the breach to incapacitate the Marine.
- In The War of the Ancients, Sargeras is pretty much unstoppable until Broxigar scratches him with his enchanted axe. That very slight injury was all the heroes needed to stop Sargeras.
- In The Ballad of the White Horse, Eldred is an unstoppable force of destruction - until his sword breaks.
"Then from the yelling Northmen driven splintering on him ran.""Full seven spears and the seventh was never made by man."
- Harry Potter: When he first tries out for Quidditch as Keeper, Ron suffers from massive lack of self-confidence that causes him to get worse with every goal he lets through. The day of the final match, he lets in a few... and suddenly has a bolt of inspiration that causes him to block every goal and sees his team win the game.
- Pact briefly features a pair of Creepy Twins, a male and female pair of Others who mimic one another's movements and fight as one. The chink in their armor is their need to manually Sychronize—that is to say, when one of them is injured, their supernatural teamwork stops working until the other inflicts the same injury upon themselves. Blake capitalizes on this opening, leading to a cycle of injury and self-injury that ends with one taking a lethal wound and the other committing suicide in the same way.
- This sums up Marvelous trainee Momono Mio's gimmick early in her career. Her proficiency in acrobatics and parkour give her evasive abilities that put even Marvelous USA's Lio Rush to shame, and she can quickly apply submission holds to boot. But she's an imperial 4'10, at most, and tended to crumple under any successful offensive maneuver, as proven in her first match for another Joshi fed where she suffered one of her quickest defeats at the hands of the barely larger and only mildly experienced Kaho Kobayashi at WAVE Young Oh! Oh! 33. For all her athletics displays it took Momono an entire year to actually put together a strategy that could win her a match Marvelous put her on the spot against Sendai Girls' Mika Shirahime. Until then the best she could do was run out the clock and settle for a draw.
- In GURPS, this is what some players refer to as the "death spiral". A Major Wound (equivalent to half or more of a character's maximum HP) can send a character tumbling to the ground and/or stun them. On the ground, defenses are compromised. Stunned, defenses are compromised even further. Being both stunned and prone cripples defenses to the point where you had better hope your opponent whiffs on their next attack or you roll a Critical Success on your own defense roll. Ergo, barring extraordinary toughness or good armor, it is best not to be hit in the first place.
- Since then, "death spiral" has become a general word for any mechanic that puts a wounded character at a disadvantage, since it tends to lead to this trope: even fairly minor penalties can easily tip the scales, which of course gets the character more hurt, which imposes further penalties, which gets them hit more, digging them ever-deeper in the hole with less and less chance of turnaround. It's generally agreed as being realistic, but not cinematic, and a dangerous mechanic to include unless its implications are well-considered.
- Dungeons & Dragons: Since there is little meaningful physical difference between a high-level character with over a hundred Hit Points and a first-level character with about six, it is usually stated that hit points for high level characters represent more luck and the ability to dodge attacks than actual toughness. So a high-level fighter could take five or six blows without suffering any meaningful harm in-universe, but when he does take harm he will be on the brink of death.
- Can easily happen in Diablo III to characters with an over-reliance on items providing Life Per Hit or Life Per Kill. During the normal course of combat, you're constantly healing more quickly than the enemy can damage you, and your health barely ever dips at all. Then an elite gets in a lucky shot with a freeze blast, and you're dead before you can recover.
- This can happen to an unwary survivor in Left 4 Dead and Left 4 Dead 2. Speed and accuracy more than hitting power are your best friends, because your objective isn't to kill all the zombies but make it to the end of the level. A player or team can do great until one attack by a Common Infected slows them down, and suddenly dozens more can pile on damage before you know it. The same goes for Special Infected but even moreso, and this trope is at its most prominent in Expert Realism mode, where survivors are Glass Cannons.
- The same is also true of Killing Floor, as the generic Clot is little threat, but getting hit by one slows down the victim because Clots can perform grabs and mire the surivors in a sea of Zeds. A player that was otherwise handling themselves just fine is suddenly at the mercy of a decidedly merciless horde.
- The normal outcome of combat in Dwarf Fortress. Sometimes a lucky hit inflicts enough pain to incapacitate a combatant, sometimes losing a limb leaves the foe literally disarmed (especially useful for bandit and invader weaponmasters) and unable to parry attacks, or sometimes it's one of various injuries that slow the victim down.
- Likewise, in RimWorld, limbs can be damaged or destroyed, and pain cripples consciousness, leaving a colonist or enemy with less ability to flee or fight back once they get hit just once. Thankfully, if someone is incapacitated but not killed, most enemies will focus their attacks on other nearby targets instead of finishing them off. This can also be bad when pirates decide to kidnap your colonists, a wild hungry animal is trying to hunt your downed colonist and eat them alive, or they are on fire and you can't get close enough to put them out.
- In Kartia: The Word of Fate, earning experience does not improve your health. What it does is improve your attack and defense stats. With good armour and a strong character, it reaches a point where enemies keep having their attacks bounce off your party members for no damage. But whenever a human or Phantom is injured, its attack and defense attributes goes down. So previously invulnerable units may find themselves being hit by attacks they'd previously been immune to.
- This tends to be how youre KOed in the Pokémon Mystery Dungeon games. A single PP-Zero trap can drain one of your moves Power Points, causing any linked moves to come apart and destroying any strategies you might have had. A Monster House can suddenly leave you cornered and helpless, especially if youve run out of crowd control orbs. A status move can leave you open for several turns in a row. A Warp trap can teleport you away from your allies, who (especially in the first games) dont exactly function very well without you there, unless you use the menus to micro-manage them. Fortunately, most of these have workarounds; unfortunately, said workarounds are mostly in the form of unstackable one-time-use items, often multiple, in a series with pretty limited inventory space to begin with.
- Prison Architect offers a income-based example. The game offers a financial bonus for every day that goes by without an incident (death, escape, or major injury), and it increases each consecutive day. It's entirely possible for a player to go thirty days or more without incident and grow reliant on the income — and then a volatile prisoner arrives and promptly punches someone unconscious. Suddenly that additional revenue is gone and makes the player's money far tighter or even plunging them into the red, which can easily spiral into a destabilized prison.
- Garrosh in Heroes of the Storm can be this if there is a Tyrande on the opposing team. Garrosh's key mechanic is that the more damage he takes, the more armor he has: which means that killing him is normally a very slow and difficult process. Tyrande however has an ability called Hunter's Mark that lowers the target's armor. There are also a few characters who have abilities that deal increased damage the more often they are used: such as Tychus and Zarya. A few other characters have what is called %health damage, where they deal a percentage of your remaining health as damage rather than a flat number. While this is technically weaker than just having high damage, it's effective against characters like Garrosh.
- In RWBY, Pyrrha Nikos is going toe-to-toe against (admittedly worn out) Cinder Fall, even with the latter being powered up with the Fall Maiden's abilities. Then Pyrrha gets hit with an arrow to the heel. Considering who she is styled after it's clear at this point in the battle Cinder's victory is assured, and although Pyrrha still has ranged weapons to attack with she dies with an arrow to the chest soon after, turning to ash as a result.