Any time people gather with the goal of hitting each other until one of them falls over, the ultimate trump card would be a weapon, spell, technique, trick or what-have-you that makes people fall over immediately, without all that annoying strategizing and healing and stuff. The One Hit Kill is that trump card.
Often, the One Hit Kill isn't humble enough to just kill, instead petrifying, permanently polymorphing, or banishing its victim to the Phantom Zone. At times, it's not even content with a single target, becoming a One Hit Poly Kill.
Usually, the One Hit Kill comes at a price. Sometimes it's a Dangerous Forbidden Technique which to use requires Casting From Hit Points, other times it's just really hard to pull off, or leaves you wide open for a counterattack. One-Hit Kills are a common spell in RPGs. In electronic RPGs, it's frequently a Useless Useful Spell because of low hit rates, inability to affect bosses, or a prohibitive cost required to cast it, if not all three combined (TabletopRPGs, by contrast, have a history of letting those pesky spellcasters make these spells insufficiently useless, turning many fights into a game of "who gets insta-killed first"). In martial arts, it frequently takes the form of the Touch of Death. If it only works at the start of a fight, it's a Back Stab. If it only works at the end of a fight, it's a Finishing Move. If every enemy attack is a one-hit kill, the protagonist is a One Hit Point Wonder.
There's also a non-lethal variant of this: The One-Hit Knockout. One Hit KO's usually don't involve anything like forbidden techniques or rare technology, just an immense amount of force applied at once, usually in the form of a punch to the face. (Bonus points if a particularly fleshy or swift and satisfying sound effect accompanies the blow.) The drawback of this is somewhat self-explanatory: It's not a kill, only a knockout. Still, it give the user at least a solid 5 minute head-start, perhaps even longer, to make an escape or thwart some evil plans before the target can recover and figure out what hit him. In certain works, this is a common reprisal when someone (accidentally or intentionally) presses someone's Berserk Button.
In anime, expect to hear the phrase "ichigeki hissatsu!" (literally, "One Hit Certain Kill") thrown around when invoking this sort of attack. With bladed weapons, cinematic representation of this trope often becomes a Single Stroke Battle. See also Chunky Salsa Rule. Often a Death or Glory Attack. Compare Coup de Grâce.
The Administration Bureau's ultimate weapon, the Arc-en-Ciel, is also a One Hit Kill by its very nature. Though it looks like a Wave Motion Gun, what it actually does is twist space-time around its target, seal everything within a hundred-kilometer radius into a pocket universe, then allow said pocket universe to Big Crunch itself. The weapon is far more deadly used on planets than in space, due to the vacuum effect that so much suddenly vanished air/land would leave behind.
Urek Mazino all the way. In what little screen time he had up till now in Tower of God, he one shot certified BAMF Viole, killed two Rankers in an instant and took another down with a simple kick. And this is just all the fighting we have seen on screen.
The invaders during the Battle of Mahora arc in Mahou Sensei Negima! switched from stripper rays to "time displacement rounds" that send the target three hours forward in the future to when they've already lost for the ultimate in battlefield removal when things got serious.
Asuna's fan also inflicts one hit kills on shikigami and summoned beings. Since she can do thisanyway, she replaced it with a BFS which can do it from a short distance.
In One Piece, it was assumed by the characters that Bartholomew Kuma's main attack was this, until it was eventually revealed that it merely sent its target flying away so fast that it looked like they vanished.
Subverted with Usopp, who uses the term "hissatsu" before every single projectile attack. None of them are ever certain hits, and definitely not kills. Then again, this is him being Genre Savvy, because the enemy is supposed to think they are.
Ussop's attacks might not be one hit kills, but he has never missed a target since he joined the Straw Hats. While disguised as Soge King, he used a large slingshot to accurately snipe at and disable marines over a mile away.
Impel Down's Chief Warden Magellan has the ability to produce lethal poison from his body. When he fights, he simply floods the room with it, making him absurdly powerful.
Not a kill, but one-hit nevertheless. While Bellamy's crew, minus the first mate, was utterly horrified that they had just irritated someone with a hundred-million beri bounty, Bellamy himself was convinced that Luffy had just created a false bounty poster to make himself seem more threatening. So, when Luffy comes around, he decides to put that theory to the test. It doesn't pan out.
Let's not forget Zoro's Single Sword: Lion Song technique, which cinched the battle with Das Bones and is suspected would have taken out Kaku had he not dodged.
A minor character example is King Elizabello the Second, who has a punch so powerful it pierced the wall of a fortress, and is said to be capable of bringing down an Emperor. However, charging it makes Elizabello basically helpless, and can only be used once per hour.
It's been summed up in Death Note that no matter what, as long as a name's been successfully written down, the victim can't escape their fate. All in the name of Anyone Can Die.
There are actually many exceptions to this (for instance if someone else wrote the victim's name at the same time it doesn't count), but none of them play a role in the story.
The exceptions still result in the victim's death, it's just that the death can be delayed by at most 23 days. In the live-action movie adaptation, this is how L beats Light: he writes his own name in the Death Note with a time of death 23 days later, thwarting the Gambit Roulette that led to Light's victory over L in the anime and manga versions.
Simultaneous (within .06 seconds) use of at least three Death Notes on the same victim will not result in death for either the victim or any of the Death Note holders, within 23 days or otherwise. Practically impossible, yes, but still there.
Another exception is if the user of a Death Note unintentionally misspells a person's name at least four times, which is far more plausible—the one time it came up, Light was lucky enough to have spelled it right on the first attempt.
Yu-Gi-Oh! has The Winged Dragon of Ra, which has an ability that is literally referred to in the Japanese version as "One Turn Kill"
There are various ways to pull off an 'Automatic Victory' in the card game, such as with the infamous Exodia (get all 5 pieces in your hand and you win, period; once that happens there's no possible defense). There was also a very-near One-Hit Kill with Wiraqocha Rasca's anime effect.
In Yu-Gi-Oh! GX, Saiou, the Big Bad of season two, took this a step further, managing something called a "Zero Turn Kill" in one episode, winning the duel before he even got one turn. (The method he used is impossible in the actual game, seeing as he used two cards that only exist in the anime. There are ways that this can theoretically be done in the real game, such as drawing all five of Exodia's components in your opening hand, but it is unlikely.)
One particularly famous example came from Yu-Gi-Oh! 5Ds, where Yusei was facing off against 3 goons who had an amazingly simple and solid effect-damage strategy going against him, dishing out a lot of damage on each of their first turns. On his second turn, however, he proceeds to unleash a combo that allows his Nitro Warrior monster to execute three One Hit Kills in rapid succession. The goons' boss even refers to it (in blatant Engrish) as "One Turn Three Kill."
Yuki Nagato in Haruhi Suzumiya - "Commence termination of data link". Pwned. This is also the reason why she won against Asakura, who was busy jumping around, throwing metal spears, while Yuki hacked the time-space program (whatever that is). It's also why Yuki was so seemingly weak for the bulk of the fight: she was devoting all of her attention to setting a single winning move.
Ranma's encounters with Herb and Saffron in Ranma ˝ ended this way, as he turned their own power against them in devastating variations of the Hiryu Shoten Ha. More notable in the case of Herb, who was knocked out instantly from this one attack (he had been punched in the face earlier, but it hardly even hurt his skin.) In Saffron's case, the technique froze him solid and shattered him.
Ryouga and Ranma both believed that the Bakusai Tenketsu ("Exploding Point-hole," or "Breaking Point" in the English version) is one of these, since it consists of making rock, soil, and (non-living) wood burst into pieces with the touch of a finger. However, after having her fun watching the two teens struggle, Cologne revealed that it doesn't work on living things.
This is why Tohno Shiki from Tsukihime is described as "the greatest wild card" (not the trope): since his Mystic Eyes perceive the concept of Death as lines and dots over everything, all he needs is one chance to kill his opponent. Given his natural killing abilities and inborn assassins' skills, all of his fights begin/end with this. In some scenarios, he has been able to kill hallways, a vampire infection (before it takes over his body), and the poison inside someone else's body; although this requires it to be Cast from Hit Points.
Shiki Ryougi from Kara no Kyoukai has even more hax, she can stab magic to death, like ghosts or telekinetic blasts.
Technically, Tohno Shiki is capable of doing this as well, except Ryougi doesn't seem to have the Cast from Hit Points issue. She also doesn't seem to have the problem of having to understand the nature of something's existence first before she can use her eyes to kill its existence.
This is due to the fact that the two Shiki's eyes work slightly differently. Tohno Shiki's eyes perceive the point of death on something, which when attacked, unravels what makes the object considered to be "alive", and in turn results in death. Ryougi Shiki, on the other hand, perceives the fundamental existence of something, allowing her to kill anything. Ryougi isn't weakened because after her accident, her "male" personality basically "died" and the space it occupied in her consciousness was filled instead by Akasha, the Origin of Existence itself, allowing her to understand everything that exists in the universe, and giving her complete control over her Mystic Eyes.
Psyren has Kyle doing this to Dholaki, by psychically boosting his speed so he can shatter the weak points on his body, killing him almost instantly.
The second summoning of Suzaku and the presence of all Suzaku Seishi notwithstanding, this is how Taka ends the battle with the fake Suzaku inFushigi Yuugi's third OVA, Eikoden. Sure, being able to send an evil being into oblivion with one punch is awesome, but in terms of action, Tamahome's reincarnate doesn't live up to his standards much.
Bleach: Soifon's zanpakutou in bankai produces a nuke. Its special attack is a One Hit Kill loaded with only one hit, and it takes her days to recuperate. Her shikai kills in two hits that occur so fast the victim only feels one.
Granted, the Bankai being a One-Hit Kill is unfortunately an Informed Ability; when Soi Fon first fires it, her opponent easily avoids it, and while her second shot hits in convincing fashion, it appears to do little to her opponent but make him angry. To be fair to Soi Fon, she did have the misfortune of breaking out her bankai in a battle against the former God-King of all Hollows, whose Story Breaker Power was second to Aizen.
The Jyuken (Gentle Fist style) is an entire taijutsu form based around one hit kills. Both Hyuuga Hiashi and Hyuuga Neji have killed targets with one well placed strike. Since the Gentle Fist can target the internal organs of a foe directly, a simple jab to the heart is instantly lethal.
Itachi Uchiha's Susanoo wields the Totsuka no Tsurugi, a sword that seals anyone it pierces in an eternal genjutsu. To date, Orochimaru and edo Nagato, two of the strongest shinobis in the world have been subjected to this....treatment.
Hatake Kakashi has the technique Kamui, which can warp away it's targets to an alternate dimension.
A quick scan of the jutsu catalogue reveals that virtually all offensive techniques ranked A or S are one-hit kills.
Subverted in that most conventional attacks in Naruto that would be a one-hit kill (impalement, shurikens, poison) are typically ineffective due to the haphazard usage of clones, body doubles, illusions, and regeneration.
Don't forget the two most well-known ones: Dragon Slave, which is only beaten by the ultimate definition of OHKILL, the Giga Slave. Then, there's also Ragna Blade, stemming from the same source as Giga Slave, just on a one-to-one basis.
Admittedly, even before the end of the first story arc, the Dragon Slave has been hit so hard with Serial Escalation that it's almost purely a Worf Barrage.
In Holyland, Chapter 29 mentions that the best way of taking on multiple opponents if you absolutely must is not to go for a decapitation strike by trying to take out the leader or strongest fighter first, but rather to use one hit knockouts to quickly scythe through the lesser fighters. It also carries the benefit of demoralizing the remainders.
In YuYu Hakusho, Kuwabara does this to Risho in the Dark Tournament arc, due to a huge powerup when Yukina arrived. Granted, it was actually two attacks (the first to destroy Risho's Armor of Clay, and the second to launch him across the stadium), but he did them in such quick succession it technically counts as one.
The manga played it straight: Kuwabara simply Megaton Punched Risho, sending him flying and destroying the Armor of Clay at the same time.
In A Certain Magical Index, Fiamma of the Right has "The strike that ends everything it touches", which annihilates anything it hits without any destructive force, meaning it cannot be blocked, and "The strike that reaches everything when swung", which reaches the target without any speed, meaning it cannot be dodged.
In Rosario + Vampire, Akuha Shuzen of Fairy Tale has this ability. Using a magical technique which 'delays her existence by a second' every one of her attacks can just cut through people like paper, taking them apart by basically cutting the reality they're standing in. Three people so far have shown resistance to this attack method, and two of those do it by blocking it with the same technique (the third uses a separate technique designed for the sole purpose of defending against Akuha).
Two people also survive it, but only because cutting them in half isn't enough to kill them. One is already dead, and the other simply put the two pieces of her body back together and let her extreme Healing Factor handle the rest.
Ichika's Infinite Stratos is capable of only this, its ability basically amounting to "rush in to disable the opponent."
In Mobile Suit Gundam Seed Destiny, the Destiny Gundam's Palma Fiocina, or Destiny Finger, is made out to be this. Whether on a basic mobile suit, or the gigantically overpowered Destroy Gundam, if this attack lands, the fight is over. The only time it fails is when it doesn't hit.
In principle, this the effect for anything with beam weaponry in the Gundam metaverse. In the original Mobile Suit Gundam, Zeon held the advantage over the Earth Federation because their Mobile Suits could practically No Sell anything short of battleship beam weaponry (which were too cumbersome to reliably hit a fast-moving mobile suit). Once the Gundam and Guncannon, the first Mobile Suits to use beam weaponry, were made, Zeon was forced into a game of catch-up and saw their numbers quickly dwindle because of the Newtype kid in the beam weapon-carrying Mobile Suit.
In later Universal Century stories, mobile suit designers all but give up on the idea of armor, since even the thickest armor is ineffective against beam weapons, instead focusing on making them as light and agile as possible. When everything can kill you with one hit, after all, the only viable defense is to not get hit.
The Palma Fiocina gets its Fan Nickname because it's a Shout Out to the Shining Finger and Bakunetsu God Finger attacks in Mobile Fighter G Gundam, which always end the fight in one hit when landed successfully. During the preliminaries of the Gundam Fight, any Gundam that has its head destroyed is eliminated. Thus, the Shining Finger involves grabbing the opposing Gundam's head and melting through it. During the finals, the corrupt Prime Minister Wong Yunfat changes the rules so that a Gundam can be rebuilt after a battle even if its head is destroyed. Cue the Bakunetsu God Finger, which disintegrates the entire enemy Gundam.
This is the premise of One Punch Man, where the protagonist can kill anything in one punch. He finds it extremely frustrating, because his fights are never challenging.
Marv from Sin City never seems to have to hit a person a second time (although sometimes he does anyway).
In The Death of Spider-Man, the Human Torch does this to the Green Goblin. Keep in mind, that in this universe, the Goblin is a nigh-invincible hulking beast with the ability to throw fireballs and not a guy in a suit as he is in most media.
Though this then shifts into Broke Your Arm Punching Out Cthulhu, when Goblin - who's fire powered in the Ultimate universe - comes back from this bigger and stronger than ever, allowing him to fulfill the name of the arc.
Later in that same arc, Peter Parker shows up, bleeding from a gunshot wound, and takes the Vulture out for a while with one web.
In Uncanny Avengers, Rogue accidentally does this to Grim Reaper after absorbing Wonder Man's strength. She was unprepared for just how much more powerful she'd become, and ended up snapping the villain's neck with one punch.
Naruto gets to deal one of these out to Sasuke in the Alternate History fic Team 8 during the Chuunin Exam preliminary battles (it's a knockout instead of a kill). It's fully explained in author's notes later on, given the context of the fight—Sasuke was still recovering from Orochimaru's seal being applied (and then removed), Naruto just watched Neji beat Hinata half to death in their preliminary battle and was understandably pissed off, and Sasuke crossed a line he should not have crossed:
Both ways. Fire the laser at a target, the target dies. Single proton torpedo to the thermal exhaust port, the Death Star dies.
Snatch has "One Punch Mickey", Gypsy bare-knuckle boxing champion. Bonus points for doing it when he shouldn't.
Godzilla possesses the "Spiral Ray" in a few of his later incarnations, a supercharged, red/orange-colored variant of his normal light-blue atomic Breath Weapon. It proved capable of annihilating some of Godzilla's most powerful foes ever (such as Super Mechagodzilla, Spacegodzilla, and Kaiser Ghidorah) within seconds. The one and only time it did not provide an immediate victory was when used against Destoroyah - and that was when it was being used for the duration of the entire climactic battle - which demonstrated how amazingly dangerous Destoroyah really was.
Of course, the lethality of the weapon is subverted when used against Godzilla himself twice. The first time, Kiryu had gone berserk from hearing Godzilla's roar and was rampaging across Tokyo before they could fire the weapon. And, the second time, the Absolute-Zero Cannon was badly damaged and could only very temporarily trap Godzilla in ice.
Kick-to-the-face in the trailer to Ong Bak is possibly the best example ever.
In Diggstown, "Honey" Roy Palmer gets pissed off and knocks out an opponent with a single punch immediately after the round starts.
A staple of Choose Your Own Adventure books are the no-escape dead ends, though gamebooks (e.g. Lone Wolf) fit the trope best with instant death if you're lacking the right skill/item or just plain unlucky — being not only accepted, but expected.
In Lone Wolf, the bow and arrow, far from being just annoying, often allows a one-hit kill for the hero, if he chooses the right target and is enough of a good shot (though some monsters are utterly immune to this).
The best Choose Your Own Adventures were better known for their creatively gory endings to your life than for their successful endings.
In the second series of The Chronicles Of Amber, Merlin knows a "neat little cardiac arrest spell." He only uses it once, but he just obliterates a Jabberwock with it. Apparently, he has a separate "death spell," but he never uses it. However, he does note that the first spell wouldn't have been a One Hit Kill on a fire angel, as they have three hearts.
In Michael Moorcock's novel "The Eternal Champion", when the Eldren use their ultimate weapon a high-powered energy gun against their opponents, who are using classic Middle Ages armor, their attack is a One Hit Poly Kill, obliterating entire lines of their opponents each shot.
The Ivory Knife in P.C. Hodgell's Chronicles of the Kencyrath, a mere scratch from which will kill; it is described as "the very tooth of Death". As one might imagine, this can be somewhat dangerous for the wielder as well. Heroine Jame carries it in her boot sheath for a long while, at first because she doesn't realize what it is, then after she knows, because she doesn't have anywhere safe she can leave it.
Balefire in The Wheel of Time instantly erases from existence anyone it hits retroactively. And it kills in such a way that even the Dark One (who has power over death and can reincarnate people) can't save them.
Balefire comes at a very high price, though. Since it kills retroactively, the past will be changed - any actions performed by the killed within for everything for a minute back to days (all according to the power of the Balefire) will now not have happened. If this happens to much, reality itself unravels, causing a Temporal Paradox that can destroy the world.
The demon-in-the-form-of-a-sword "Stormbringer" in Michael Moorcock's Elric of Melnibone series kills any non-magically protected human in one blow (it also eats the victim's soul). "Mournblade" is a similar demonic sword, and one story reveals that there is an entire race of these demons — all of them taking the form of swords.
"Morganti" weapons in Dragaera are all one-hit killers. They also destroy the soul of the victim, making revivification impossible, and also making it impossible for the victim to travel the Paths of The Dead to the afterworld.
Any of several magic words in the Inheritance Cycle which cause instant death to whoever they were directed at.
In Fred Saberhagen's Book of Swords series, Farslayer can kill anyone (including demons and gods) anywhere as long as they don't have Shieldbreaker or Woundhealer to save them.
In The Chronicles Of Narnia, Jadis uses the deplorable word and basically one-shots an entire planet, resulting in no more subjects for her to rule. But that's okay, a pair of children help save the day on Earth and Narnia
Shardblades from The Stormlight Archive cut the soul of living things rather than the flesh, and cut straight through almost any inanimate matter without any effort. Slicing the blade through one of a victim's vital organs kills them instantly. Slicing it through a limb "kills" that limb, rending it permanently paralyzed and numb. The only beings that are likely to give somebody with a Shardblade a problem are those with a suit of Shardplate, (which can withstand a Shardblade, at least for a while) or beasts so large that the blade can't easily be sliced into their vital organs (and these are BFSs an average of six feet long, so the fact that there ARE beasts that big, and a lot of them, says something about this world).
In The Destroyer book series, the martial art of Sinanju is mostly one-hit kill moves.
In Billy Budd, the eponymous character is accused of conspiracy and mutiny aboard a British man-of-war by the ship's master-at-arms, who is doing this to fight off his "strange attraction" to the androgynous sailor. Upon hearing this, Billy freezes up, unable to say anything in his defense. Eventually, he answers the only way he can - by punching the liar in the temple. The man dies on the spot. Unfortunately, Billy is found guilty of murder by the tribunal of officers, despite them all being sympathetic to the boy, and hung the next day. Interestingly, the tribunal was about to find him not guilty as a weird case of self-defense, when The Captain intervened and convinced them of the necessity of the execution.
Live Action TV
In Smallville, especially early seasons, there are very few opponents that Clark doesn't take out in one hit.
Game Shows: In its simplest sense, the one-hit kill was a contestant winning the game outright on the first play of the game, before his opponents even have a chance to play. Although rare, the most notable examples were:
Tic-Tac-Dough: The "red box" "Bonus Category," which immediately allowed the contestant another turn if he/she answered a three-part question correctly. The categories were moved to other boxes after the question, and the "Bonus Category" always appeared in an adjacent box or other space that allowed him/her to set up and eventually complete a tic-tac-toe. Played correctly – and it often was – a tic-tac-toe was completed without the opponent getting a chance to play (although he/she was always invited back to play the next game). Eventually, in the interest of fair play, the category was retired, in lieu of the modified "Double-or-Nothing."
Spinning three jokers on a single spin automatically won the game for that contestant ... provided he/she correctly answered a question. While it has happened several times on the game's first spin, only once – the first time it happened – did it result in the opponent not getting to play. (The opponent, a challenger, forced his smile as he was on and off the show in roughly 90 seconds.) The ""first-spin triple joker" quick kill was averted thereafter by allowing the challenger – who always played second – an opportunity to catch up by continuing to answer questions until they either caught up, won by surpassing the opponent's score or giving an incorrect answer; however, the game would end if the challenger spun the triple joker and answered the question correctly.
Like its sister show Tic Tac Dough, the 1977-1986 syndicated version had special scoring categories, which could be used on the player's first turn to build a huge lead and virtually assure themselves a win, simply by severely pressuring the opponent. Categories fitting this example were "Fast Forward" and "Bid," both which allowed contestants to answer multiple questions in a single turn until they either stopped and kept their winnings ("Fast Forward") or completed the terms of their bid to earn the cash ("Bid").
Concentration: Solving the puzzle after making a match on the game's first turn.
In the finale of Life, Crews kills Roman with one blow to the throat.
In the competitive robot combat show Robot Wars robots could be battered into submission and some robots were in fact powerful enough to disable an opponent with a single lucky blow. Robots could also be flipped over and those with no way to right themselves were immobilized and defeated. However there was only one guaranteed way to defeat an enemy robot in a single strike: throwing it over the wall and out of the arena. The first time it happened, no one could believe their eyes.
Not to mention, the pit.
Arguably, the Zat'nik'tel in Stargate SG-1. Although it takes two shots to kill, it only takes one to win. The third disintegrates. Yum. Too bad it makes all those clicky buzzy noises when you turn it on. Sort of ruins the element of surprise.
It should be noted here that the disintegration idea was quietly phased out after a few seasons when the writers realized that it was stupid. It's even mocked in the 100th episode special Wormhole X-Treme, which mainly existed to mock things like this.
Done on CSINY, where a martial arts expert killed the victim of the week with a single blow to the back of the neck.
It's pretty common in North America for a pro wrestler's Finishing Move to be used as a One Hit Kill. There are many, many matches where one participant spends the whole match getting the snot beaten out of him, then seizes an opportunity to hit his finisher and win the match. Note that this is less common in Mexico, Japan, and Europe.
The One Hit Kill effect is essentially what made Diamond Dallas Page so dangerous in WCW. You could beat him up all day, but all he had to do was hit the Diamond Cutter and he'd come out on top — and he could hit the Diamond Cutter at a moment's notice, from fifty-two different positions.
The Tombstone Piledriver: In the 2 decades that The Undertaker has been using it, you can count the amount of people who have even kicked out of it once on your fingers. In fact, when Shawn Michaels kicked out of it at WrestleMania XXV, the look on Undertaker's face was something akin to "WHAT IN THE HOLY HELL OF FUCKNESS JUST HAPPENED?!?!"
Dungeons & Dragons has quite a few, mostly of the "fortitude save or die" variety, including:
Massive Damage — A well known modification to the game, in which doing a certain amount of damage in a single attack (usually 50 points) means that the poor monster who suffered from it has to make a fortitude save vs. Instant Death. Not quite as used when campaigns have higher-level characters who can dish out 50 damage a turn on average.
Finger of Death — 7th-level arcane spell; this one's a generic "save or die" spell.
Circle of Death — the 6th-level version that does this to every creature within a certain radius.
In earlier editions, this spell was known as the Death Spell, and in AD&D, it dealt death depending on the Hit Dice of those it was cast upon. And unlike Circle of Death, there was no saving throw against it — if you were hit with it and you had less than nine Hit Dice, unless you had enough people of equal or lower Hit Dice than you to use up the spell's power before it got to you, you were pretty much screwed. And to make things worse, in Second Edition AD&D, if you were killed with a Death Spell, you could not be raised or resurrected, and the only way you could be brought back was with a Wish.
Slay Living — 5th-level divine spell; similar to finger of death, but clerics use it instead of wizards. It's a "Touch of Death" type thing, too.
Phantasmal Killer — 4th-level arcane spell; requires a Will save to disbelieve the frightening illusion it creates, and if that's failed, you must make a Fortitude save or die, with success dealing regular damage rather than a one hit kill. There's an upgraded 9th-level version, weird, which is much harder to save against and deals more damage if you succeed. This one's particularly aggravating because death ward, which is supposed to protect you against save-or-dies, does exactly squat against it — because it's an illusion.
Cloudkill — 5th level arcane spell; a cloud of toxic gas that kills you without a save, makes you save or die, or deals Con damage, depending on how many Hit Dice you have. Can be disrupted by strong winds.
Disintegrate — 6th-level arcane spell. In 3rd and 3.5 edition, it does 2D6 points of damage for every caster level you have (up to 40D6), but in earlier editions, it was a One Hit Kill that could reduce you to little more than fine dust on a failed save.
Intelligent swords in the earlier editions that had a special purpose could have this as its special purpose power, delivering this effect on any hit with the weapon when it was wielded against any enemy that the weapon in question was dedicated against. As you can well imagine, swords like these gave those they were dedicated against some very good reason to fear.
Symbol of Death — 9th-level arcane spell, kills you and anyone else near it when it's triggered.
Imprisonment — 9th level arcane spell of the Phantom Zone type; permanently locks its target in a small bubble beneath the earth. Victims don't die there, but instead have time stopped for them and are placed in untouchable suspended animation, so they can't even attempt to break the spell, because their mind has stopped. And unlike being dead, it takes another 9th level spell to undo. Downside to its overwhelming power is that the player does not get loot from the enemy. Of course, enemy NPCs have no reason to care about loot...
Power Word: Kill — 9th-level arcane spell; kills you without a save if you're at 100 HP or less.
Because not all of the "save or die" spells target Fortitude (some target Reflex or Will), a high level wizard is a Game Breaker, as he may kill nearly anything by guessing which save is the weakest.
Destruction — 7th-level divine spell; similar to finger of death, but it destroys the foe's body on a failed save (making resurrection more difficult) and inflicts more damage on a successful save. Damn CoDzilla.
Blasphemy, Holy Word, Word of Chaos, and Dictum are all alignment-based spells that brutalize targets of the other alignment with negative status effects. However, if you are a certain number of Hit Dice (a measure of hit points) below the caster, you just drop dead, no save. Most of the game's most famous antagonists (The various Archfiends, for example) have these abilities built in.
In the case of casting one of these spells on your home plane, any extraplanar creatures that would be affected by these spells—regardless of whether they heard the spell being cast (creatures who are in their home plane already are only affected by the spells if they are capable of hearing them)—must make a Will save at -4 or be banished to their home plane for 24 hours. It's not lethal, but it's a quick way of putting these creatures out of commission (at least in your current plane) for a while.
The Forgotten Realms setting adds Undeath to Death, which is a 6th level "Will save or die" specifically keyed to undead, available to both clerics and arcanists.
Monks have a move called Quivering Palm which allows them a one hit kill (a remotely activated one hit kill no less). Its uses, however, are annoyingly limited ("Once per week?!Wizards can do it six times per day!"). It's done somewhat better in Neverwinter Nights 2, where you can use it after resting like all other abilities, and at higher levels can reach a fairly dangerous difficulty class for the saving throw that's on a par with the most over-specialized wizards out there.
As for Weapon Properties: a lucky shot from a Vorpal weapon will decapitate its target (which usually kills it), a Disrupting weapon will take out undead (as long as they fail a fairly lousy Will save — but since you can whack them over and over, they have about 3-4 rounds till they fail their save), and the overpriced Epic weapon property Dread will take someone out on a lucky shot as long as they fail a piddly (or at least, piddly compared to any creature you plan on facing) save.
Certain weapons can also deliver One Hit Kills upon hitting certain targets. The Hammer of Thunderbolts, if you've met all the requirements to bring it to full power, can kill any giant instantly upon a failed save.
A cleric can out-and-out destroy undead with a single good turning check. Once per day, a cleric of the Sun domain can do it with a mediocre turning check.
Also, in the first edition of the game, you had the Assassin, whose signature ability allowed him to one-shot anyone on whom he gained surprise, provided he succeeded on the special attack roll.
Even if the roll failed, weapon damage was automatic so it could still kill the victim. Also first edition blade venom works when you inflict damage with a weapon so you could still force a poison save if they survived the initial roll and the damage so you had 2 or 3 chances to kill them depending on their hit point total.
The Rules Cyclopedia's Sleep spell could send you to sleep without a save for 4-16 turns if you had 4+1 Hit Dice or less, and during that time, anyone can use a bladed weapon to kill you instantly regardless of hit points. If you wielded a sword with the Slicing talent and scored a natural twenty, the target of the attack had to save vs. death ray or be One Hit Killed, suffering triple normal damage even upon a successful save. A missile with the Slaying talent that hits the target for which it is keyed also forces a save vs. death ray upon its victim to avoid instant death.
The Living Death campaign had a special base class (Doctor) who had a skill only they could take (Doctor) and which they were required to spend 1 skill point on per level. With this skill, they could either restore hit points to an ally, or force a Save Or Die from an enemy. Lets do the math: the skill is always 1d20 + level + INT. It could be higher if you spend the 0-3 additional skill points you have the option of spending, or spend one of two skill increasing feats. Let us assume you did neither. Your roll is simply 1d20 + level + INT to set the DC of the Fortitude save of the enemy. This is an instant kill on pretty much any opponent who has a Fort save. And, before you point out that the attack still requires a successful hit at a -4 penalty, I'll also mention that the campaign disallowed armor, so everyone was ridiculously easy to hit.
D&D's fourth edition seems to mostly avoid this, however, with attack powers inflicting mainly straight hit point damage and possibly nonlethal side effects. The game has numerous powers that are described as one-hit kill effects, but by their rules text they're actually not; most infamously, the "Finger Of Death" spell simply deals damage similar to what other spells of the same level do. There are still some powers (mostly monster attacks) that can kill or petrify a target regardless of remaining HP, but even those are not quite instantaneous and allow at least two chances to shake off the attack via a successful saving throw before the final effect kicks in.
However, powers that were meant to take someone out temporarily can be made permanent through the use of the save lock trick, which stacks penalties to make it impossible to escape. With certain powers, like stun, this is effectively a one hit kill. With one specific paragon path daily power, you can permanently banish a target to a pocket dimension where they can't do anything. While possibly game-breaking, it also makes for a good excuse for Sealed Evil in a Can.
While Vorpal Weapons aren't as useful as they were in previous editions, rolling a critical for a Vorpal Blade allows you to continually reroll damage as long as you do max damage on the die, semi-mimicking the One Hit Kill properties of its original version.
Warhammer 40000 has several attacks that cause automatic Instant Death, including the D-Cannon (opens a tear in the reality on top of the target), Force Weapons (rip out the target's soul. Before 5th edition this used to be Kill Outright, and would even kill targets that are immune to Instant Death) and Blissgiver (send the target into an unrecoverable coma). However the price goes to the Vortex Grenade, and it's big brother, the Vortex Missile, which sucks anything in the area of effect into the Warp. If a model as much as touches the template they die with no saves of any kind allowed, regardless of any immunity to Instant Death (superheavy vehicles and gargantuan creatures take D3 structure points and D6 wounds, respectively, and thus might survive). Depending on how the grenade scatters, this may also include the thrower however. This was amusingly proven in a battle report where a legendary and practically immortal hero of Blood Angels single handedly charged into enemy lines armed with a Vortex Grenade, whiffed the throw and sucked himself into the Warp.
The newest addition to the list being the Space Wolves Psychic Power "Jaws of the World Wolves" which will take anything touched by its line of effect out regardless of wounds, invulnerability or anything else, only a timely reaction can save them.
Chaos has had a version of the same called the Gift of Chaos. The difference is that it has a shorter range, only works against a single target and forces the target to do a toughness test instead of an initiative test. However, you can select any individual model in the squad you're targeting, making it very good for eliminating characters in the unit.
As can Jaws Of The World Wolf, except that it can snipe multiple characters in the same unit.
Anything with a Strength value of "D" for "Destroyer" does just as much damage as a Vortex template, though it can only do it once instead of popping up repeatedly and is not one-shot. The Eldar scout titan is so awesome it can spew out four 5" blast templates with essentially the same effect as the Vortex grenade every turn.
If you take one wound from Interrogator-Chaplain Asmodai's Blades of Reason, you will die. Luckily, armour protects against it. Less luckily, there's only so many armour saves one can reasonably pass.
Rogue Trader brings us the Navigator power The Lidless Stare. When mastered, anyone who takes damage from it (so that's anyone within 15m looking at the Navigator who he beats on a Will check) has to pass a Toughness test or die immediately. Yes, I mean anyone. It's a good idea to make sure your friends aren't looking...
Giants have a random attack table. One of these, Stuff In Pants, instantly kills the unfortunate victim. If you manage to kill the Giant before the end of the game, they escape unscathed though, not that you'd want to live after being through that.
For all the American tropers out there, remember that Games Workshop is British, so it is a slightly more Squick meaning of "Pants"... assuming giants bother with wearing two layers of clothing.
There's also "Eat", which has much the same result, but is slightly less disturbing.
Warhammer also has the Killing Blow rule, which allows a weapon to instakill the target if you roll a 6 to wound. Some weapons can also Slay Outright, which means a single wound inflicted by such weapon causes the target to lose all their wounds.
The next tier up from Killing Blow, Heroic Killing Blow, allows the guy with it to instagib not only human-sized opponents, like standard Killing Blow, but giant monsters as well.
Additionally, a famous early combo based around the card Channel (which allows you to exchange life for mana on a 1-1 basis) and a direct damage spell such as Fireball (which allows you to convert mana to damage on a 1-1 basis) allowed you to fry an enemy on full life in 1 shot. With a number of ultra-rare cards and a bit of luck, you could do this on the first turn. Unsurprisingly, Channel was eventually banned from all competition.
It's actually even worse. The "number of ultra-rare cards" you needed for this first turn kill was ONE: Black Lotus (or a Mox Ruby/Jet in a slightly different variant). The rest of the cards involved were dirt-cheap commons and uncommons.
When Magic was released, there was no upper limit on the number of any given card you were allowed in a deck. The development team was well aware that you could build a deck consisting of 20 Lotuses, 19 Timetwisters and a Braingeyser (or Fireball) for the kill, but they reasoned that most people simply weren't going to buy enough few packs to get that many rare cards, and that anyone who actually built one would soon find themselves without an opponent willing to play against it. (The early sets were not designed with Tournament Play in mind, and it shows.)
Considering that the Legacy and Vintage tournament formats are defined by these kinds of combos, decks that have more than one versatile Combo Breaker to disrupt them, and decks that kill the Combo Breaker decks, it's not surprising that with 20,000+ cards at their disposal, innovative players have found tons of ways to pull this off with varying degrees of success.
To clarify, storm lets you get a copy of the spell in question for each spell cast previously on that turn. This may seem powerful but not ridiculous until you remember that there are tons of spells that simply make mana... to cast more spells. And that countering the original spell doesn't stop the copies, making this a disconcerting aversion to One Bullet Left. (On the other hand, Stifle the Storm trigger and your opponent will get the original spell, but NO copies. Cue Unsportsmanlike Gloating and a possible Rage Quit.)
With the recent Infect mechanic making some creatures deal "poison counters" instead of normal damage, it's entirely possibly to play a creature on the first turn, then throw enough Buff spells at it when it attacks to kill the opponent on the second. (You only need 10 poison counters to kill an opponent, and there are no practical ways to heal poison like normal life)
Of course, if your opponent kills your creature after you use your buffs, it could be slightly awkward for you.
Plus there are many, many effects that one-shot creatures, Deathtouch being a basic one (any damage done to a creature is enough to kill it).
And now, the planeswalker Vraska the Unseen spawns no less than three Assassin tokens, each of which is only 1/1 but can kill a player in one hit.
The Yu Gi Oh CCG has a series of 3-Tributes creatures whose effect states that if they defeat the opponent by reducing their LP to zero, you win the entire match - not just the game, the match, regardless of how many games you played already and what the situation is. Only one of these, however, is even legal for use in a deck (the rest are all high-end tournament prize cards), and it had a short stint before being outright banned from tournament play.
There are many ways to achieve one hit wins, like powering up a monster to ridiculous levels with equip cards or using a card like "Wave-Motion Cannon."
Whole decks are made around the concept of the OTK (One Turn Kill) and the key cards are usually subsequently banned and/or limited so as to prevent such a deck from being constructed. Some popular examples:
Rescue Cat OTK: Last Will banned. This did not stop Rescue Cat from being misused, so it was evenutally banned too.
Chaos Emperor Dragon/Yata Lock: Both Chaos Emperor Dragon and Yata Garasu banned *
Technically its a One Turn you're completely totally screwed with no chance of saving yourself as you get pecked to death for 20 or so odd turns. But the point stands.
Cyber-Stein OTK: Cyber-Stein banned
Chimeratech Overdragon OTK: Cyber Dragon, Future Fusion, and Overload Fusion all limited to one. Future Fusion is banned as of this writing, due to continued misuse.
Chain Strike OTK: For a while, Chain Strike was limited to one, which killed the deck. Now it's at two, but Ojama Trio, a key card, was limited to one. Recently, Ojama Trio was also brought up to two.
Exalted has the Celestial circle spell Blood of Boiling Oil. Three guesses how it kills the victim. There's also a Resplendency any Sidereal using a resplendent destiny of the Sword has access to that works like this, though only against mortals.
There's a few other Charms and spells that are one-hit-kills, though many of them are limited in WHAT they can kill instantly (mostly just mortal human beings or REALLY low-Essence magical entities). Also, due to the way the game's "extras" rule works, any attack against one that succeeds by enough becomes a OHKO as well.
Five Metal Shrike's Godspear deals Infinite damage and anything near the impact point disintegrates at quantum levels. The only other sources of Infinite damage are falling into the Void, which is to say "You cease to exist", and the Eye of Judgment of a Titan citadel, which is basically the Godspear + five-mile radius + ridiculous amounts of required infrastructure to build.
Scion has the Death purview's level 10 power and Avatar power. The former can one-hit-kill anything with a Legend of 8 or lower. The latter can one-hit-kill a titan.
GURPS considers this too potentially unbalancing, but still has the Coma and Heart Attack conditions, which force you to "save or die" unless help arrives quickly.
The only thing worse is a massive radiation dose (over 4000 rads). You get to make one HT roll. On a critical failure you die in agony, on a failure you die in agony, on a success you die in agony, and on a critical success you die in agony, but it takes longer.
Tactical nukes. Which often come in grenade form (blast radius 500 meters, maximum throwing radius 50 meters - somehow, no one survives long enough to report this design flaw).
Plasma generators, basically flamethrowers on steroids. Which malfunction frequently, meaning the fuel tank strapped to your back is about to explode, leaving you a choice between undoing the cumbersome straps and running for it (and incurring a hefty fine for abandoning such expensive equipment) or attempting a difficult repair procedure (one roll just to turn off the alarm, a second to stop the explosion, a third to actually make it fire again). Oh, and expect blowback if you fire into a strong enough wind.
The "Falling from Great Heights" table goes from "five feet" all the way up to "Orbital". Which has actually been used in official adventures.
Having The Computer find out you're an actual full-blown Communist. Or a machine empath (It really hates being manipulated that way).
Getting a natural 20 on an attack in Hong Kong Action Theatre is not only an automatic hit, but an instant kill or KO for any character of Moderate importance or below, depending on what weapon you're using and what your intentions are. If you get a natural 20 on a Major importance character (such as all player characters) or above, he or she is entitled to a Toughness roll in order to take normal damage instead.
Call Of Cthulhu has several different levels of One Hit Kill. On the lower end, we have Yig the snake god, whose instant kill can be dodged or parried and is ineffective if you're wearing some sort of armor it can't go through. Above this, there's the Dhole, which is the size of a battleship, so its attack can't be parried and ignores armor. And then we have Cthulhu...
This is the idea behind the "donk" deck category in the Pokemon Trading Card Game: They are capable of KOing a Pokémon on the first turn (before an Obvious Rule Patch, they were able to do so before the opponent could even take a turn). Among competitive decks, it is not uncommon for a player to have only one Pokémon ready when a match begins, and if that one ready Pokémon gets KOed, that player loses the match. The most notable "donk" deck featured Machamp, who could automatically KO any Pokémon who isn't evolved during a season full of strong unevolved Pokémon—Machamp was responsible for a large amount of official tournament matches during that season ending within five minutes.
Final Fantasy I probably featured the largest variety of one-hit kill spells as standard black magic, several of which actually were very effective against specific monster types (even more as the party leveled up). There was also one enemy called 'Sorcerer' (named 'Mind Flayer' in the remakes) whose physical attacks inflicted only Scratch Damage but with a side effect of instant KO — pray they don't get to strike first when you encounter a group of 5. The ProRing, despite being obscenely expensive, protects against instant death, and renders Sorcerers completely impotent, but the game doesn't tell you that, ever.
Final Fantasy VI has a trick that can make the Doom spell 100% effective on most enemies. This includes most bosses. However, it was corrected for the GBA version. There are also some weapons (the Assassin's Dagger and the Ichigeki are two of them) that will randomly use a highly-accurate Death spell for free (along with a unique animation) when you attack with them.
Final Fantasy XI, for balance reasons, doesn't have players get these abilities. Doesn't stop some boss monsters, however. Even then, some monsters have abilities which kill them, but deal area damage based on their HP (Unless they have the Ninja job 2-hour, then nothing happens to them). Considering most of these mobs have thousands of HP, well, do the math.
Players will soon have an instant death ability, in the form of the new avatar Odin, which will have AoE death (but with less accuracy the more mobs that surround it), on all normal mobs.
The Tonberries creep slowly towards you then stab you to death. In some cases, it's not an instant death attack, but just does obscene amounts of damage. Later versions added the "Karma" ability, which deals damage equal to the amount of damage the Tonberry has taken, and it always has more HP than the maximum your characters can reach...
From Final Fantasy IX, Zidane's Soul Blade move, which gives the target the status effect of the weapon equipped with 100% success rate (barring immunities). With the Masamune equipped, which has the Doom status effect, all you have to do is survive until the countdown runs out.
Also, in Final Fantasy X, Kimahri's Doom Overdrive has a 100% success rate (again, barring immunities). Kimahri's Thrust Kick and Auron's Shooting Star Overdrives knock enemies right out of the battle. There's also Anima's Pain ability, which causes Death, and Yojimbo's Zanmato (NOT an Overdrive, despite what many people think) which instantly wins the battle for you and works on ANYTHING, even bosses. You have to pay a redonculous amount of Gil to make him use it in some cases, though. Lastly, many abilities can be customised with Deathstrike or Stonestrike, which pretty much kills ANY enemy that doesn't have immunity to Death or Petrification with one hit. It also make catching many monsters much easier.
In Final Fantasy Tactics the twin assassins Celia and Lede have an ability called "Stop Breath", in which they reach out to their target and do just that. It's 100% effective, unblockable (except via rarely-used items), and no, you never get to play with it yourself, because the villains always get the coolest toys.
Along with several other One Hit Kill attacks, many of which belong to the same class (Assassin, obviously).
One of the optional characters, Beowulf, has a petrification attack that works surprisingly often. Also, Cloud has an attack that kills, petrifies and/or stops his opponents. Not only is it his most reliably lethal attack (his other strong attacks, which simply do HP damage, are too slow to hit much of anything), it's also, surprisingly, one of the easier ones to obtain.
The infamous "Slots" spell almost always has an instant victory result, if you can time your button presses correctly (Though in the case of Selphie's "The End" and "Rapture", and Lady Luck's CONGRATS!, you don't actually kill the opponent. They just sort of go away). All Slots techniques bar Selphie's also have the chance to cast the same instant death spell on your own party, often with the result being just one reel off.
The enemy ability "Repose" (previously known as "Calmness") used by the top-tier foe Rest in Kefka'sOne-Winged Angel transformation, as a final attack. The character must block it or suffer an instant kill.
The "Roulette" Blue Magic, which chooses one victim among all the current combatants. Unblockable, but doesn't kill the undead (they regenerate, as it's an "instant death" effect).
Final Fantasy VI also has Edgar's Air Anchor - when it works, and it works surprisingly well, the enemy gets one more turn before instantly dying.
Most instant death attacks do not work on The Undead, which regenerate to full health when struck by one. However, in Final Fantasy VI there are a few abilities that kill an enemy Deader Than Dead, shown by an animation of the enemy disintegrating to tiny bits. The Odin and Raiden summons, Cyan's ultimate sword technique and the Scimitar/Zantetsuken weapon are the only four that can one-hit kill even undead foes.
Aside from Death spells and Zantetsuken, Final Fantasy IV has Globe/Object 199, which usually does profane amounts of damage instead of inflicting instant death. It's just the damage tends to be in excess of however much HP the target is expected to have, so it achieves the same effect. This is the reason you keep the Attack Node (Defense Node in the DS version instead) alive and blast away at the CPU once its counterpart is slagged.
There's also the Jumbo Cactuar's "10,000 Needles, which hits for 1 damage 10,000 times in a series where the HP Cap is 9,999. One game has an ability that allows you to exceed this cap, but the same game has a bonus boss called the Cactuar King with a 99,999 Needles attack. Guess what the boosted HP cap is.
Wild ARMS 2 played with this a little. There was an optional boss that would completely regenerate its health every three turns, and 75,000 HP is no number to scoff at in this game (The Superbosses have 100,000). While using an Instant Death ability seems counter-intuitive in a boss fight, it's actually the way he is supposed to be defeated.
By pressing the F1 button, you can do this to your opponent. It doesn't work on everybody, though...
Every character in Guilty Gear has an "instant kill" technique. Land it and you win the round; miss, and your super bar disappears completely.
This was even more egregious in the PS1 version; the setup for the instant kill was either punch+ kick or a well-timed block, there was no penalty for missing, and you won the entire match.
In the Spiritual Successor, BlazBlue, Instant Kills have been replaced by Astral Heats, which seem to have been excessively nerfed. They can only be used in a tiebreaking final round of a match, require 100% of your super bar, and can only be used when the opponent is below 25%, at which point any normal super move would likely win anyway. After all, There Is No Kill Like Overkill.
Continuum Shift seems to have un-nerfed them. You can now use them in round 2 of 3 if it would win the match for you, and your opponent can be at or below 35% health.
In Dwarf Fortress, any hit that results in a bisection is always lethal, as well as immersing a creature in liquid and then freezing the liquid (magma into obsidian or water into ice), or caving walls or floors in on an enemy. Other favourite, but less reliable kinds of instant death are magma (although some creatures are immune to it), dropping bridges on the enemy (except for the biggest creatures), and decapitation or piercing the brain with a weapon or shattered piece of skull (as long as the target isn't undead and has only one functioning head left).
Some forms of evil weather, such as the ones found in Waterburned, are instantaneously fatal to dwarves.
Some of the more devious traps, like the one that fires a large amount of serrated disks at whatever poor invader steps onto them, usually result in Ludicrous Gibs and Chunky Salsa all 'round.
One of the starting weapons in ColourFire's arcade mode is a virus that infects enemies and kills them in one hit, blowing up into even more viruses. The only trouble is its short range, and that it has to wear down their health from the inside before they die.
In Baten Kaitos: Eternal Wings and the Lost Ocean, the two magic users, Xhela and Mizuti, both had One Hit KO special moves. Xhela's was her level XIII special "Seal of Water" and Mizuti's was her level IX special "Planet Soul". There are also a few magnus that have death chance, and a few with 100% chance (such as the "Death" tarot card).
In addition, a few select enemies and bosses have this. For example, during the boss fight against Geldoblame after he touched the End Magnus, he has the ability Forfiet Your Life, which causes 100% chance of death unless you have some kind of resistance, which is hard to get by that point in the game.
Probably based off the Power Word: Kill example in Dungeons & Dragons, the Blade of Awe (usable from Bribing Your Way to Victory) in Adventure Quest has a small chance (0.1%) to instantly kill whatever you are fighting. There are dagger, spear, and staff variants of the same weapon with have the same ability, and dark and fire versions of the Blade of Awe which have a 0.12% chance instead.
Prince of Persia: The Sands of Time has an interesting variation. The ultimate sword kills any enemy in one hit, but you usually charge your time powers by stabbing stunned enemies with your secondary weapon, and there's no stunning when they turn to dust as soon as you touch them. But of course, by the time you get the ultimate sword, you've lost the Dagger of Time. So no harm, no foul.
The final boss in the PlayStation remake of Lunar Eternal Blue has an attack that deals about 2,000 damage. Just for reference: if you're dedicated, you might have a single character who has more than 500 hit points.
The final boss of Lunar The Silver Star also used that spell (Fate Storm), but unlike in the sequel, it just killed the target outright. Particularly bad because the boss in question could doublecast, and would always cast Fate Storm along with Hell Wave, a powerful attack-all spell that could easily leave you in critical condition. So you had to revive the dead person AND restore your entire party, unless you learned the pattern and prepared for it beforehand.
The final boss of the PSP remake of Lunar The Silver Star punishes the player for abusing Mist Barrier by casting a spell that makes his next spell deal 2,000 HP to the entire party on the last turn it's active.
Golden Eye 1997 features the Golden Gun weapon, hindered by its one bullet magazine and that it only does enough damage to deplete either armor or health. There is also the cheat but equally devastating Gold Walther PPKPP7, which can kill anything in one shot, and has a 7 round magazine.
The Sky Canyon boss in Sonic Advance 2 has a hand-swat attack that will end you regardless of whether or not you have rings or a shield.
Some bosses in Sonic Rush have a one hit kill attack, too, but Eggman's generous enough to give you an audio cue ("Get ready to be schooled!").
In Act 2 of the Sonic Generations version of Seaside Hill, Sonic can run over the water by boosting. There is a giant chopper that attacks if you spend too long outside of certain areas. If it attacks, you lose a life, no matter what. Rings? Won't help you? Going as fast as you can? Won't help you. SUPER SONIC? IT'S NO USE!
In Kingdom Hearts II, the final boss Xemnas can attempt to grab Sora, which can only be avoided with invulnerability from something like Reflect or a limit attack. Should he succeed, he'll attempt to rip out his heart. Riku can save Sora from this, but if his HP is too low when he gets caught, you're out of luck, as it'll be completely impossible to stop it in time.
In the Final Mix version of the same game, Terra has an attack that is a bit like Heartless Angel; it rapidly drains your HP, and you have to push a button at the right time to stop it. Should you fail to do so, or push the wrong button? Instant death.
The final boss of Sora's story in Chain of Memories has Doom, in which you have six seconds to break six of his cards, or you die instantly. Combine that with the sleight that scatters your entire deck including your reload card, forcing you to pick them up again, and...
The Zantetsuken attack introduced in the final mix version of Kingdom Hearts has a fairly high chance of OHK Oing normal enemies. It becomes much more effective in later games with the addition of commands like Magnet and Zero Graviza that gather your enemies together.
The second installment's Shoryuken kills any boss in one hit, provided you remain in contact with him long. Morph Moth is an exception as he pulls a One-Winged Angel in the middle of the battle. Curiously, so is Zero, by virtue of his ability to frickin' block your attacks.
The third game downgrades Zero's Saber to a 2-hit kill, but it's still damn useful and a lot easier to get, especially since using it with the Buster upgrade causes it to fire out a crescent beam with the same effect.
Another "2-hit kill" attack is the upgraded Nova Strike in X8. All Bosses (and I mean all) fall to two hits (regardless of the health of the boss, the first hit always reduces the health to around 25% so the Boss could trigger its Desperation Attack). The previous incarnations of the Nova Strike is Game Breaker material enough, but this one?
One forgotten one is in Mega Man 2: No matter how many times, you can't defeat Wood Man? Have you tried hitting him with a full-power Atomic Fire after he drops his shield? As the link would attest, the whole goddamn thing's cyclic. (Two hits required in the Japanese version/America's "Difficult" mode.)
Like Wood Man, Metal Man has a weakness that will drop him in one hit outside the original Japanese version, except in this case, it's his own weapon. Sure, you can't do it until the second fight with him, but it's still damned funny.
Also, if aimed exactly right, the Air Shooter can hit Crash Man with all three tornadoes in one shot, killing him instantly. Even in the Japanese version, it will knock off over 60% of his life, making the next hit nearly a guaranteed kill.
Headshots with a sniper rifle in pretty much every FPS will instantly kill it's target regardless of circumstances, unless it's a boss or invincible. Whether or not you can pull off headshots with other weapon varies, and if you can, it tends to be a damage multiplier rather than a guaranteed kill.
Which can be exploited as a valid means of killing in games like Unreal Tournament that have teleporting "weapons."
In Urban Terror, a shot to the head with any weapon is a OHK, unless they have a helmet, in which case some weapons won't deal enough damage; even with a helmet, a sniper round to the head means death. The Remington sniper rifle is a OHK anywhere, except the arms, in which case it does "only" 67% damage.
This is subverted in the Jedi Knight series, where The Force-sensitive enemies will dodge your sniper shots, even if they don't see you. Of course, this is because the lightsaber is the most powerful weapon in these games: one slash is usually enough to kill any non-Jedi enemy and one well-placed slash with the "Strong", Darth Vader-like style is enough to kill anyone except the bosses. Jedi Outcast also includes the hidden "realistic combat" mode, which unlocks the lightsaber's full decapitation and dismemberment potential, making each strike (even mere touch!) lethal. That also affects the enemies' lightsabers.
In Halo 2's Legendary difficulty, the Sniper Jackals kill you instantly no matter where they hit.
In the Syphon Filter series, headshots and explosions are guaranteed instant death for the player as well as enemies (except for certain bosses), regardless of armor and health levels.
In Combat Arms, the headshots were a one hit kill of course, but at one point, getting shot in a, ahem...sensitive region for males would also score a insta-kill, along with the humorous announcement "Nut Shot!" with a picture of two cracked walnuts. It was later nerfed to only occur when the fatal bullet (or melee attack) would nail the unfortunate player in the nads. Female characters could suffer this too, for balance reasons, but lacked the extra effects the males had.
Call of Duty 4 and beyond add a knife that is an instant kill if it connects. Bashing people with your gun in earlier games was also generally instant death, unless you did it with a pistol.
Since we are on the topic of Unreal Tournament, some incarnations of it include the InstaGib mod, which gives all players Shock Rifles with nearly unlimited ammo and each hit is lethal. This mode was available in Quake III Arena, too, but with railguns.
Sort of with the headshots. Sniper Rifles would always be a one hit kill, and shotguns were a one hit kill in the head at close range (along with any other part of the body) but other small arms would just deal more damage than normal.
The RPGs in 2 and 2142 were one of the few weapons that would result in the victim not able to be revived by a medic, regardless on where they were hit.
In Super Smash Bros Brawl, some Final Smashes consist of one powerful attack that is (nearly) guaranteed to KO anyone it hits. Zelda's, Marth's, and Captain Falcon's are prime examples. Assembling the three pieces of the Dragoon is also an instant KO, even if the target hasn't suffered any damage. Unless, of course, you miss.
Similarly, the Home Run Bat item has this effect — landing a smash attack with it is an almost-guaranteed Home Run Hitter KO.
Roy's fully charged B attack in Melee. Ike claims this ability in Brawl.
Ganondorf's up tilt is instantly lethal in Melee, and mostly lethal in Brawl.
The final boss of Subspace Emissary Tabuu has one (or more, at least in Boss Battles on Intense) instant kill attacks.
Jigglypuff's Rest is capable of killing at 0% depending on the situation, but will usually one-hit KO anyone close to or above 40%. The price? The hitbox is pretty much confined to Jiggly's eyes, and if you aren't placed right the instant you use it, you've got 3 seconds to sit helplessly while your opponent charges up a smash. Also, even if you do get a kill, unless it's off the top, your opponent is going to come back to life before you wake up, which means they will kill you if you're above around 80%.
The "broken but balanced" hack Brawl Minus gives one to Ganondorf in an effort to make up for his place at the bottom of the tier list in the vanilla game. His slow Warlock Punch does 666% damage and knockback to match, sending enemies off-screen instantly.
The Fist of the North Star fighting game for the Atomiswave and PlayStation 2 has the Deadly Fist Blows that works similar to the Instant Kill from Guilty Gear. They require a bit of build-up, however, as you must hit your opponent until the constellation under their lifebar is reduced to a single glowing star, which usually takes more than one round. This seems to be to ensure that when you use the Deadly Fist Blow, the entire match is over (not just the round). Since it's possible to combo into these, and they don't require any special stance (unlike the Instant Kills), which allow them to be used as surprise attacks, Deadly Fist Blows have seen use in Tournament Play, and many players consider finishing the opponent off with one to be a point of pride.
Igniz from The King Of Fighters 2001 had a move called "Brutal God Project" for his SDM where he pins your character back against the wall and unleashes his entire repertoire of (immensely high damage) attacks on you consecutively. It is, unsurprisingly, a 1-hit kill for the most part (Note that in this game: character stamina gets higher as you sideline more characters as strikers so a one man fighter with three strikers could theoretically survive "Brutal God Project" at full health). And he most commonly performs it as a follow up to his reversal special move which juggles. There's a reason that Igniz's portrait is at the top of the SNK Boss page.
Ralf's Galactica Phantom SDM/LDM in (The King of Fighters 97/98/99/2000/XI) qualifies if it hits as a counter. On XI, though it depends on the damage setting (as in who you're fighting. One of a team, yes. Single person, e.g. boss, no.)
SoulCalibur IV also has these now, a first for the series. They're called "Critical Finishes" and they work in a similar way to Fatal KOs in Fist of the North Star. Constantly forcing an enemy to block powerful attacks, or Guard Impacting them around a lot, causes their Soul Gauge to turn from green to a flashing red. Once fully emptied, a single strong hit will send them into a vulnerable state ("Soul Crush"), and the Critical Finish can then be performed.
PSI Flash in EarthBound can do this. It's in the main character’s powerset and actually works on bosses. Should it fail, it typically leaves a status condition.
Then, there of course are PK Beam Gamma and PK Fire Omega from EarthBound Zero.
Also, Giygas' inexplicable attacks can sometimes cause a one-hit kill.
The flashes of light caused by the Upgraded Robots in Mother 3 instantly kill one party member.
Mother 3 also has the Ultimate Chimera, which instantly causes a game over when it reaches the party. They don't even get a chance to fight it.
The entire point behind "Heaven & Hell" or "Hell & Hell" modes in Devil May Cry.
ToeJam & Earl has the Total Bummer! present that when opened automatically kills your character.
Counter Attacks in Assassin's Creed tend to result in some extremely brutal one-hit kills, i.e. slapping a guard in the face to spin him around and then stabbing your sword into his hip and out his crotch. Moreover, the assassin has full invincibility frames for the duration of the counter kill animation.
In the second game, while the archers, agiles, and regular guards with berets die in a single "counter kill," the regular guards with helmets have to have low health before this happens (counter attacks before that will only drain health as the Assassin drives them back), and brutes and seekers can only be countered by polearms, axes, or bastard swords (wielded by brutes, seekers, or mercenaries). However, in return for the smallest window of opportunity, Hidden Blade counters are always a OHK against any weapon, making it the best melee weapon for any player who can consistently time the button press, and the second game made it much easier to pull off, with fewer drawbacks.
In the later Splinter Cell games, Sam can kill or knock out any guard he gets close enough to with a single quick and very efficient stab of his knife or punch/palm strike to the brain.
Conviction has the Mark and Execute system. Although you need to melee kill an enemy to make use of it, it allows you to mark up to four enemies and OHK all of them instantly (or fast enough that it doesn't matter).
In the Spiritual Successor, Hard Corps Uprising, enemy snipers will attempt to lock onto you, and if you get caught in the crosshairs, they'll fire a bullet that does 4 points of damage if it connects, enough to kill any character in Arcade mode but it can be survived in Rising mode thanks to life upgrades (most other attacks only deal one point of damage to your Life Meter).
In Skyrim, you get to be on the receiving end - giants can smash you with their clubs so hard that you fly into the atmosphere, and dragons have an attack where they break your neck with your teeth if you're standing too close.
Many, many games of NetHack have ended with the message "Oh no, <monster>'s using the touch of death!" The player can sometimes acquire their own version of this spell, called Finger of Death, after the D&D spell listed above.
Not to mention being turned to stone, being transformed into a green slime, being disintegrated, being dragged underwater, being eaten (not instantly fatal to you, but fatal if done to/by pets), swords that can behead or bisect you or an enemy instantly, and of course the wand of death.
The canonical One Hit Kill and Yet Another Stupid Death is "You fall into a pit! You land on a set of sharp iron spikes! The spikes were poisoned! The poison was deadly...". Being on the wrong end of this is a sure sign that the Random Number God is out to get you, as it requires: firstly, that a spiked pit be generated; secondly, that you hit the chance that the spikes are poisoned (1 in 7 each time falling into the pit); and thirdly, that the poison is classified as deadly (1 in 20 chance each time you take poison damage). However this can be avoided through Acquired Poison Immunity.
Travis' Darkside Mode allows for one-hit-kills of a most violent degree.
Shinobu has a pair of near instant-death attacks after she Turns Red: she can take you from full health to two points with her supercharged Gengoken attack, and her multi-Sonic Sword attack will off you if she hits you with all the blades. And she is the third boss of the game.
Harvey Moisewitch Volodarskii and Bad Girl also have instant-death attacks, the former if you fail to break out of his magic box, and the latter if you fall for her trap. Henry breaks one out once his health reaches Turns Red territory; it's the one that looks like the Stinger from Devil May Cry and plants you into the concrete.
Surprisingly, there are fewer one-hit kills in the sequel, but they're noteworthy:
Captain Vladimir's extended Kill Sat laser and the final boss' violent defenestration attack.
More frustrating is the final boss' attack, though, who is more or less a checklist of The Computer Is a Cheating Bastard, with teleporting, chaining attacks, ranged attacks, multiple forms, and possibly most frustrating, a OHKO that really can be ANY move, so long as you're on a specific third of the stage (or, if the attack is too strong, almost anywhere).
Travis gains another OHK in the sequel: turning into a tiger and ripping apart the suddenly-terrified enemies.
The "game ender", a unit or structure that can only be built at or near the end of the tech tree, and even then only at considerable time and expense, but once built, (almost) uncounterably devastates your opponent, is a staple of RTSes. Nuclear warheads are popular, but a recent trend is to include a mobile unit with a short to medium ranged weapon that can one-shot anything.
And the Sniper's headshot ability, when fully charged, inflicts 450 damage,(and 518 with the Machina) exactly enough to kill an over-healed Heavy and (way) more than enough to kill anyone else.
On a technical level, only telefrags and falling into pits are One Hit Kills. However, the examples noted deal up to 500 damage without any modifiers and boil down to One Hit Kills except against a Spy using a the Dead Ringer or a Heavy affected by a stun during the time it gave victims a 50% damage reduction to make it less overpowered.
Sawblades, trains, and the Horseless Headless Horsemann deal damage equal to double your current health.
On the note of "so much damage that it's an instant kill, assuming there's no damage reduction," taunt kills. Taunting with a certain weapon out (it varies depending on the class) will make your character play through an animation that will kill any enemy unfortunate enough to walk in front of you at the wrong time. They do 500 damage, and as mentioned above, the normal maximum health count is 450. Most of these can destroy buildings instantly as well, whereas the backstab and headshot rely on Critical Hits to work, which don't affect buildings.
The Half-Zatoichi is a katana for the Soldier and Demoman. If you hit an enemy wielding one of his own with it, it does damage equal to three times his current health, causing an instant decapitation.
Time Killers was notorious for having this. A well-placed hit at any point in the round would instantly kill your opponent.
Showstopper from Paper Mario The Thousand Year Door and Up and Away from Paper Mario. Surprisingly enough, they weren't as useless in battle as one hit kill moves in other games, although the latter move gives no EXP upon use.
Geno from Super Mario RPG has an attack (the Geno Whirl) that deals 9999 HP of damage when timed just right. Since no enemy in the game, including bosses, has that much HP, that makes it a One Hit Kill attack. However, it does only minor damage to said bosses (except one: Exor, after losing his protection, so it comes in handy for players who consider him to be That One Boss), along with certain other enemies, namely the chest-based ones such as Box Boy.
Some enemies also have attacks that instantly kill the character hit by them, unless said character is wearing an accessory that blocks them (or the player has really really good timing). Even one of the forms of the final boss has one. Depending on your timing blocking the one hit kill attack, either it was a success or you suffer an HP To One effect.
In a partial aversion of the trope, numbered Phantasy Star games tend to feature a variety of these, often cheap to cast and geared to work on certain types of targets (inorganic or living). Even better, some of them are almost reliable! PSIV has a particularly large number of them; between techniques, skills, and combination attacks, nearly every character can kill some kind of enemy instantly. Played straight in that they don't work on bosses.
The first two Fallout games feature notorious examples of this trope. When scoring a critical hit on the head, eyes, or torso, you will, if lucky, land a hit that destroys the enemy immediately (and messily). This can lead to strange situations thanks to the game's damage mechanics: a character in full power armor might take zero damage from a critical hit, and then die instantly from the pain.
It did the same thing in Ultima Underworld, except it was more of "despawning" everything in the game than killing everything in the game (no corpses).
The Ultima series is also famous for its glass swords. One hit kills both the enemy and the sword.
Kill Counters and Superstyle moves in Heavenly Sword. Kill Counters are performed by hitting Triangle as soon as an attack is blocked, Superstyle moves are performed by beating up enough enemies to fill your power gauge, then pressing Circle near an enemy. Superstyle moves are also used on some bosses, where doing so triggers a QTE that defeats the boss if performed successfully. Kai's arrows also kill most enemies in one or two hits, depending where on the body you hit them.
In Iji, if General Tor's Eidolon gathers three charge orbs, he gets one of two attacks: If you've been using the Resonance Reflector, he'll fire a hail of nano to rip into you. If, on the other hand, you haven't figured out the trick, he'll prepare to fire the Phantom Hammer bunker-buster. This is signified by the orbs' dispersion and regathering into his gun barrel, and then he stomps the ground for a pull. If the seismic wave hits you or you stay in firing range too long, better luck next life.
By the way, the Phantom Hammer doesn't just blast your health to 0 on a hit, it reduces all your stats to 0 at the same time. In terms of the story, this means that Tor's Phantom Hammer completely annihilates Iji's nanofield. With one hit.
At the end of 2 trials in the third Ace Attorney game, Trials and Tribulations, you have to press the right statement/present the right evidence, or your ENTIRE life bar is wiped out. In the Japanese version, Godot calls this an "infinite penalty", while the English version calls it "the unlimited penalty". Partially justified by the fact that, when Godot threatens it, Phoenix's argument is based entirely on circumstance and conjecture, and failing to prove it shows that he most likely made it all up.
Several enemies in Zombies Ate My Neighbors could be taken out with one shot of the right weapon. Some were damned obvious (use silverware on the werewolves or the footballs on football players), some were pure Guide Dang It (using the Martian Bubble Gun on the giant ants or the tomatoes on the Martians).
The Tenchu franchise is based around stealth kills. If you attack a guard who is unaware of your presence, you kill him instantly and cinematically as only a freakin' Ninja can.
Shin Megami Tensei games have the Mudo and Hama spells, both being single-target spells with 40% chance of inflicting instant death. Those are the weakest variants of the instant death spells in that particular franchise. Their most powerful forms, Mamudoon and Mahamaon, have a 60% chance of inflicting instant death on everyone in the party, yours or the enemies'. Of course, elemental affinities can mess with this. Both spells, however, also come in damage flavor. In the Digital Devil Saga series, Hama instead dealt a percentage of damage based on your current Health.
Satan, in SMT2, could just point his finger at someone, and the character would die. No chance of failure. The final boss only had to use his voice to do the same.
Satan, again, in Digital Devil Saga 2, along with spamming Mamudoon on your party, has Retribution and God's Breath. God's Breath deals 9999 Almighty-elemental damage to everyone in your party. HP cap is at 999. You do the math. Retribution just plain instant kills a character, and is also Almighty-elemental, so no way of guarding from it.
Demi-Fiend, from Digital Devil Saga, has Gaea Rage (also known as Game Over), that deals anywhere between 7,000 - 12,000 Almighty-elemental damage to your entire party. Again, HP cap is at 999.
Mitra, the second sector's boss, has Light of Order, which is a guaranteed instant kill towards a random demon. Thankfully it never targets you, but you'll still find yourself spending turns reviving demons (you need one turn to revive, then the next turn to bring them out to battle).
Attacks that cause Stone are effectively one-hit kill attacks. In the case of demons, the effect can be removed, but if you get hit with Stone, game over.
Beelzebub, at least from Nocturne and onwards, has Death Flies, an Almighty-elemental spell that deals plenty of damage and has 100% chance of instantly killing anything that doesn't nullify or repel Curse-elemental spells. The good news is that you may acquire said skill later in the game once you've leveled your Beelzebub adequately and in the Digital Devil Saga series.
Metatron, conversely, has the opposing move, Fire of Sinai. Massive Almighty-type damage, 100% chance of killing everything and anything not immune to Light spells.
Trumpeter, in Nocturne, has an Almighty-elemental skill called Evil Melody that deals instant death to the character with the lowest % of HP left.
Ahriman has a skill that will kill you if you don't play his game.
Eternal Rest instantly kills any character currently asleep in both parties.
God's Bow, a skill only White Rider has in Nocturne, kills anything not immune to Hama.
Another Rider, the Pale Rider, has Pestilence, a skill that inflicts Almighty damage and a chance of poison. Casting it with poisoned enemies will instantly kill them.
Stinger, one of Dante's moves in Nocturne, also has an instant kill factor.
Hell Gaze, another Death-elemental instant kill move.
In Persona 2: Eternal Punishment, there are lots and lots of instant death moves. Of course Hama and Death (called Light and Dark) but also many physical attacks, whether it's a main or added effect, various elemental combos that shouldn't be used on demons that can repel them and a few non elemental attacks that can be used by both your party and opponents. Some demons will use kamikaze instant death attacks. Phoenixes deserve a special mention as they will afterward revive their kamikaze fellows. Non elemental attacks like Multi Dimension will work on anything that isn't immune to instant death. Many are surprisingly effective. Death Roulette will do wonders on a single non boss opponent and will take care of those Boss in Mook Clothing. Some of them don't work that often but can't be blocked either and will help against those magic reflecting demons. Others will always kill anything... but at a price. Armageddon will do it for free but you can only use it in a New Game+ and you'll need loads and loads of money to obtain it. A few personas have the special ability to (sometimes) deal instant death to your opponent if the equipped character dies.
In Persona 3 and Persona 4, two Persona have "Die for Me" and Samsara. They both act like Mudoon and Hamaon, respectively, except that the chance of success is more likely around 80% as opposed to 60%. And that's just against enemies with no weakness to it.
Actually, the spells "Die for Me!" and Samsara become a Game Breaker in Persona 4. They have a 100% success rate to ANY enemy that doesn't resist/block/repel Dark or Light, respectively. Other that bosses, it's actually extremely rare to find normal shadows that block both light and dark.
Also in both games, the ability "Ghastly Wail" is instant, unavoidable death for any character afflicted with Fear. This also works on some bosses, such as P3's Strength and Fortune.
Another attack in Persona 4, "Summons to Yomi", is instant death to any character with any status ailment whatsoever. The enemy that uses that attack knows this, and likes to prefix it with one that afflicts party members with random status ailments.
In Persona 4 Arena, the Instant Kill attacks in BlazBlue have been un-nerfed even further, as all it takes is for your character to have a full SP meter in a deciding round, and it will take out any opponent, regardless of how much life they have left.
Naoto's Hamaon and Mudoon supers will instantly KO a foe if their "Fate" meter (which counts down from 13 when the opponent is hit by Naoto's gun or Persona attacks) is reduced to Zero.
Elizabeth has enhanced versions of these moves (Mahamaon and Mamudoon) which can be used at any time once she has enough SP, but they turn out to be Awesome, but Impractical because:
They have an absurdly long charge-up time and the opponent may not be in position once the spells activate, and
The spells disappear immediately if Elizabeth is hit (even while blocking).
They must have been counting on players noticing the broken chain on either side of the fridge, which is fairly hard to see thanks to the graphics. The lesson there is to not attempt a no-saving run on your first playthrough. Oh, and Silent Hill 3 did have another of those One Hit Kill puzzles; remember what you do with the hair dryer?
Silent Hill 2's first encounters with Pyramid Head. Anyone paying the slightest amount of attention knows on sight that if that knife comes down on you, it's over. The first bosses of SH 1 and SH 3 also have instant-kill attacks.
The boomerang from Link's Awakening, which you have to trade in your shovel for, can kill the final boss in a single hit if you aim for the eye. In the same game, stealing a product on a shop and coming back will show the owner zapping Link to death due to the theft.
In The Wind Waker, you will eventually get the Light Arrows, which are so powerful they obliterate ANY normal enemy in an explosion of light. For that matter, almost any time the Light Arrows are featured (Ocarina of Time is an exception because they only stun enemies). They OHK all normal enemies and are powerful enough to stun Ganondorf, The King of Evil.
Link can learn two sword techniques in Twilight Princess that do this. The Mortal Draw is tricky to use, and doesn't work on certain enemies that are defended in the front (you need another sword technique entirely for them), but it can still be effective in certain situations. Against bosses, it won't be an instant-kill, but it will hurt like hell!. The other technique is the Ending Blow, which delivers a deadly stab at enemies when they're knocked down in the floor after being attacked.
In Spirit Tracks, the Dark and Armored Trains can kill Link instantly if he fails to dodge them while travelling with the Spirit Train.
The Guardians patrolling the Silent Realm can kill Link instantly. The fact that they are only found in the Silent Realm, where Link loses access to his sword, can make encounters with them rather tense.
There are three examples of obstacles that, instead of simply making Link reappear at the start of the room where they hit him (a tradition for the series), they actually kill him: The giant rolling boulder in the Earth Temple, the statue of Buddha in Ancient Cistern that descends when Link gets the Boss Key, and the lava overflowing a certain underground passage in Fire Sanctuary.
As in Twilight Princess, the Ending Blow allows instant kill to enemies when it's executed well.
Twilight Princess also has a one-hit kill against Link regarding the Zora Armor. The armor is weak to fire attacks, which makes Link take double damage, but if he falls into lava with the armor on, it's instant death — regardless of how many hearts you have.
Pokémon has several moves that will knock the target out with a single hit: Guillotine, Horn Drill, Fissure, and Sheer Cold. They are balanced out by a very low accuracy, but they're still banned in Wi-Fi and online tournament matches. Also, Articuno learns both Mind Reader and Sheer Cold, giving it a guaranteed Two-Hit KO.
In Generation I, these moves always fail if the opponent has a higher Speed stat than the user. In later generations, this is changed so that instead they always fail against opponents of a higher level.
One particularly nasty implementation of the move Sheer Cold comes in the form of a glitch which enables you to make a Machop or its evolved forms learn the move. One of Machop's possible abilities is No Guard, which makes its attacks always hit at the expense of always being hit by opponents' attacks too. Do the math, and you get an instant KO which never misses. The reason Sheer Cold is preferred with this trick is because nothing is immune to Ice-type moves, and even a not-very-effective hit will be a guaranteed KO.
A Pokémon with full Hit Points holding a Focus Sash will survive a potentially OHKO move with 1HP instead. The ability Sturdy also protects against OHKO attacks — it was later modified to also work like a Focus Sash.
Total Overdose gives Ram a variety of One Hit Kill options, but only the targeted headshot is worth any appreciable points. Most Loco Moves are instantly deadly in a pinch; the Tornado sprays dual uzis in 360 degrees, El Toro allows Ram to charge and headbutt enemies to death, the Explosive Pinata lures in enemies before detonating, and the Golden Gun is loaded with 4 bullets that autokill enemies in the general direction it's fired. These may seem like game breakers, but given the volume of enemies and increasing style-point requirements, their use isn't generally ideal, and mostly reserved for panic situations.
Count Vladmu a.k.a. Flash has his namesake ability, signaled with flames at his feet before he parts his robe and glows brightly. If you so much as look his way during this, you either forfeit a doll (Chelsea automatically, Bunny on Recall) or head back to your last save point. Direct contact with his head by anything other than the girls' feet is also instant death.
Chelsea, as a boss, has a mode where crosshairs lock onto you. If you stay in one spot too long, you get a headshot, which kills you no matter how much health you have.
Dechronos!Bunny throws BFSes on the last ten to fifteen percent of her health. Touching one effectively paralyzes Chelsea while Bunny beats a doll out of her. What, don't have a doll? Say hello to the last save point, sucker! Oh, and don't touch her at this time, either.
Warcraft 3 has the Doom spell on Pitlords, which will oneshot any mook he happens to target with using a fairly hefty (40 dps on guys with around 200-1200 life) dot, after which you get a pretty tough demon spawned. Doesn't work against tougher mobs though, nor heroes.
Also the Finger of Death
Also, in Warcraft 2, the Mage's Polymorph spell turned any unit into a neutral critter. Unlike in the sequels, the spell is permanent, making it work like a one hit KO.
Fate/stay night had two examples. Lancer's Gae Bolg, the melee form of which would always strike the heart if he called its name (though he never really got the chance to do so). The stronger ranged form is technically blockable though Archer was the first to ever do so and could not continue fighting afterwards. Second, True Assassin's Noble Phantasm would automatically destroy the heart of his opponent, though it seemed to be fairly easy to avoid. If it DID hit you, you were dead though. Except Kotomine, who is immune to it due to the taint of Angra Mainyu. He still lived another two days after happening to have his heart destroyed anyway though.
There's also Bazett's ultimate move in the sequel Fate Hollow Ataraxia, called the Fragarach. Being the ultimate counter to any enemy's most powerful attack (and only their most powerful attack, otherwise it's a worthless counter), it sends her Noble Phantasm flying into the opponent's heart before they make their attack. The problem with this move is that it functions in exactly the same way as Lancer's Gae Bolg, which also is magically designed to have pierced the target's heart before the attack is even made. Thus, if the two moves were used on each other, both fighters would be killed.
The RPG spinoff Fate Extra gives us another example - The Assassin Li Shuwen's mastery over Chi and the fighting style of Ba Jiquan allows him to disrupt the energy flow of any opponent he strikes with a single touch, leading to his opponents dying after a single hit as their bodies ceases functioning. The technique is referred to in the game as 'No Second Strike' in reference to his historical boast that he never needed to hit an opponent a second time.
Kengo: Legend of the 9 (aka Kengo Zero in Japan and Europe) has a gameplay mechanic where your Stamina, although it can be depleted by many things (including walking), only itself affects one thing — whether or not that person can be one hit killed; basically one of the swordsmen initiates a Kumitachi (sword lock), the two attempt to physically overpower each other as they move around, draining Stamina, and one who loses all his Stamina is susceptible to, after being thrown, being one-hit killed.
The Fire Emblem series has the recurring skill "Lethality", also known as "Silencer", learned appropriately enough by the Assassin class. It dispatches the foe instantly, even if a regular attack would have done no damage whatsoever.
Left 4 Dead has one hit kills on the common infected if they are set on fire. The sequel also supports this and also has incendiary bullets, making any gun similar to Golden Eye 1997's Golden Gun on the common infected. Shoving the back of a common infected while they are idle (just like Metal Gear) is an instant kill and is also an achievement. The sequel also introduces melee weapons, which can kill any zombie in a single strike (except Chargers, Tanks, and Witches), regardless of difficulty. The Magnum can also one shot common infected, regardless of difficulty or where you shot them.
Doing a Goomba Stomp to a common infected will also kill them instantly and break your fall.
Melee weapons in general can One-Hit Polykill the common infected, and one hit kill the majority of the special infected.
On Expert Level, the Witch only has to touch you to inflict a one hit kill.
The Witch can also do this on any difficulty in Realism mode.
Barbarian may well have had the first One Hit Kill in the history of one-on-one fighting games, and without being a gamebreaker to boot. You could use a decapitation move at any time in a fight (complete with a shower of badly pixelated blood), but the long buildup time made it very easy for the other player to dodge or interrupt.
The Critical and Deflect Critical moves in Onimusha 3, though they are phenomenally hard to pull off. Once pulled off, though, you can chain them using the "Chain Critical" move (after learning it), allowing you to kill loads of enemies in one move. While in Onimusha mode, using either of these moves kills every enemy on the screen.
Golden Sun had several. The psynergy Condemn can instantly kill although rarely. The summon Charon has a chance to instantly kill. The Djinn Serac and Whorl may OHKO enemies and Gale will sometimes blow enemies off the map, but you won't get the experience. Obviously none of them work on most bosses and the chance for some is rather low. That doesn't stop Dullahan from instant killing you with Charon. In addition, certain weapons such as the Assassin Blade and the Crystal Rod had unleashes that had the potential to occasionally OHKO enemies, and they even worked on the bosses in the Suhulla Desert.
Menardi and Karst have the Death Scythe attack, which can do this. The Ice Queen's Icy Kiss attack can also oneshot someone in Dark Dawn, a bit of a wake-up call due to the lower level at which you encounter her. Skorpna-type monsters in the Grave Eclipse have a OHKO move called Drag Down.
Hisoutensoku has Reimu's Fantasy Heaven, which is so strong that if you use it in the third round of a match, it gets its very own theme music. The move is one big Shout Out to the Hokuto no Ken example above; the theme music that plays in the third round version is suspiciously similar to the Fatal KO theme from the HnK fighting game, and the move is called "Musou Tensei" in Japanese, which is also the name of Hokuto Shinken's ultimate technique.
Occasionally in Dissidia: Final Fantasy, you will encounter gold manikins that have exactly one HP. Hitting one of them with an HP-damaging attack at any point in the match will result in instant victory. However, early on in the game, some of them will also have insanely high Bravery levels, meaning they can do this to you, as well.
The infamous Iai-strike Build, man. It kills the majority of things in simple two button presses: one to instantly Break your opponent, the other to execute the 9999 HP damage. Character HP naturally caps at 9999. Oh, and some characters' HP attack *cough*Yuna's pony laser*cough* also damage Bravery, potentially making it actual One Hit Kill. Feral Chaos suddenly looks trivial.
This is the whole point behind WET's Golden Bullets mode. Every hit is an instant kill on a mook.
In most 2D games, the Screw Attack is lethal for non-boss creatures. It's a reason why it's often obtained late.
Metroid Prime Hunters in multiplayer mode has the Omega Cannon, a weapon so powerful that it will kill anyone, including the shooter, in a single hit because the blast radius is so damn large. The weapon can only be used once and you have to pick up another if you want it again. It only appears in one level and people generally avoid picking the level it appears in since it becomes a race to the top to see who can get the weapon first. Naturally, people who cheat will love to use this weapon.
Metroid Prime 3: Corruption also has an example in the Nova Beam. By itself, the Nova Beam is just a high-frequency weapon that can damage enemies regardless of special Phazite armor they may be wearing. Use it in conjunction with the previously gained X-Ray Visor though, and you can start targeting some enemies' internal organs for instant kills.
In Ace Online, the Bomber-type B-Gears are walking One-Hit Kill (named OHKO by players in-game) dealers. The de facto B-Gear weapon, Bawoos, regularly deal 1000 HP damage per missile, while B-Gears are famous to be able to throw at least 6-8 of them forwards, and 12 or more downwards. Coupled with the fact that most Gears' HP range in around 6-7k HP total, OHKOs are frighteningly regular.
Another B-Gear example would be their Finishing Move, Big Boom. This move sacrifices one's own gear to take down others equal to its own Energy. With custom made Veils (armors), BBs can hit up to 14k damage, effectively acting as a very effective crowd-control move.
While you have to whittle away half her HP first, Reid's Omega Seal becomes a One Hit Kill for optional Duel Boss Valkyrie in Tales Of Eternia.
Also in Eternia, and given a callback in Tales Of Vesperia (PS3), bringing the Dhaos cameo from Tales of Phantasia down to half and pulling off Indignation is an instant kill in homage to Phantasia. In Vesperia, doing this is the only way to unlock Indignation for Rita.
Instant kills also exist in the form of fatal strikes in Tales Of Vesperia, though they only do this to normal enemies, and can only be triggered after depleting one of their fatal strike gauges through use of arts. In the PS3 version, Clint can use this on you if he or his allies land enough hits. Notable in that it'll still kill you even if you have the otherwise invincible level four Overlimit active.
Tales of Phantasia also had a set of instant-death spells for Arche (and a summon for Claus), each with a varying accuracy as well as those pesky urchins in Moria Gallery touching which simply kills your character (except Arche).
The majority of Hitman's attacks: strangling, poisoning, explosives and sniper shots, although, seeing as most of his opponents are mere humans, it's not surprising.
Technically, Disintegrate just does 32 000 damage. One would be hard pressed to find anything in the game with more than a couple of hundred hit points, though.
In the fourth level of Renegade, you have to beat up four mooks armed with knives. And then three more of them, accompanied by a mob boss. Who has a gun. No, you can't pick up weapons. Have fun.
World of Warcraft has most of its raid bosses set to an "enrage" timer that activates at the point the programmers determined to be most logical for the difficulty cap for the boss, upon which point the boss in question gains massive attack strength and attack speed, resulting in instant and rapid death for each member of the raid. Depending on the overall encounter conditions, the boss might be able to do this to the whole raid at once (Algalon uses Ascend To The Heavens to blow up the whole raid, Yogg-Saron extinguishes all life, kaput!)
The Lich King uses his Fury Of Frostmourne to wipe the whole raid near the end of the encounter, though the raid is resurrected shortly afterwards and wipes the floor with him.
Some boss abilities are basically avoidable One Hit Kills. Avoiding might mean to acquire an effect that protects against a good chunk of the damage, running behind line of sight obstacles, interrupting the spell or simply running away whenever it comes up. Tanks may or may not be tough enough to survive it regardless, but everyone else has to avoid it anyway. Some bosses even go as far as coupling this with getting stronger when they kill someone with such a spell.
Additionally, it has become a standard tactic for any player that has a displacement/knockback effect (Elemental Shamans, Balance Druids, Fire Mages, and any particularly skilled Death Knight) to allow in their PvP strategy a means to place their opponent between them and a high cliff, causing instant death to anyone that doesn't have a means of slowing their descent (Mages/Priests respective 'Slow Fall' and 'Levitate' assuming they aren't an engineer with a parachute).
You can also survive being thrown off a cliff with Warlock's 'Demonic Circle', although it requires good timing.
Or simply use one of the Paladins two Invulnerability spells and ignore the damage.
The Warriors Execute skill (and similar skills) is meant to be this, although usable only if the enemy is already at low health. Normal opponents and players will die (barring damage-preventing effects like the Cheat Death talent), but against a raid boss it only deals heavy damage.
The Warlock spell "Curse of Doom" wasn't specifically a One Hit Kill, but designed to have the potential. It does the most single-tick damage of any of the Warlock's spells, but takes a minute before the damage is applied. If the damage kills your opponent, it spawns a Doomguard demon. On lower-level creatures it can be a One Hit Kill, (if your squishy warlock can avoid being killed for 60 seconds) but once you reach boss-level it just does a whole lot of damage. It's since been changed to Bane of Doom which instead deals hefty damage every 15 seconds (not One Hit Kill tier, though).
Deathwing is a unique example in that his final attack is something that you've already suffered through- The Cataclysm. This is the closest thing an MMO can get to a Non-Standard Game Over, as letting him use it causes the screen to fade to black as you and everything else is utterly destroyed.
Monks have a variant of this, Touch Of Death which instantly deals the monk's max health in damage to an (NPC-only)enemy that has the same or less HP than the monk's maximum, effectively killing them instantly and ending the fight. For the Brewmaster, this means you can one-shot normal monsters, since, as the tank spec, they have a high max HP.
Counter-Strike features the infamous AWP (which, incidentally, isn't actually an AWP; it's an AW Super Magnum) which yields a one-hit kill no matter where the bullet hits its target.
Alex's defining move as it's OHK - eating people. The simple grab and Consume move will kill any normal military or infected enemy, and heal you in the process! Not so for the hunters, though, which need to be weakened before consumption.
A fully-charged Blade Air Slice is a One Hit Kill for just about anything but hunters, and his devastator moves are OHK for everything in the area of effect.
In the Disgaea series, any attack that successfully hits somebody standing on a panel with the Deathblow geo effect results in instant death, regardless of whether the attack actually did damage. Also, in 2, the Samurai class has the ability to randomly score an instant kill with standard attacks while in critical health, and the Bone Dragons possess the Vendetta evility in 3 and 4, which allows for a low chance of an instant kill upon a successful counterattack.
The Farsight XR-20 railgun, which is like Counter-Strike's AWP, but even more broken. Not only can it instantly kill any unshielded target with one shot regardless of hit location, but it can also shoot through any number of solid objects. It gets worse, when you put the Farsight into its secondary mode it will also track the enemies for you, meaning the player could basically kill anything by pulling the trigger anywhere on the level. Broken indeed.
There's also the golden DY357-LX, a golden version of the normal revolver. It destroys anything that can be destroyed in one bullet.
Both the Farsight and the gold magnum have virtually unlimited penetration, so they would instantly kill as many people as you could get in a straight line.
The Crossbow has a secondary fire that turns it into a one hit kill weapon, which was far more useful than the primary fire, "Sedate". Add to that the fact that you could retrieve bolts if they missed, and you had a potentially infinite-ammo instant kill weapon.
The Tranquilizer Gun also has an instant kill function, although it ate up a lot of the gun's ammo and functioned as a melee attack.
Paul Phoenix has a move called "Burning Fist" (Back+ both Punch buttons) which will not only take a second to charge up, but will take out the opponent in one hit (and send them flying backwards). Some YouTube videos show Paul playthroughs comprising of nothing BUT Burning Fists.
Jack has an attack called "Dark greeting". He takes a step forward, with sparks flying from him, and makes a quick chop downwards with his hand. If the opponent is in range, they're down. Ditto for the Wind-up Gigaton Punch.
Kuma's "Fatal Wind", which is extremely difficult to hit with.
Miguel in Tekken 6 has an unblockable move. He puts his hand over his mouth and laughs, then he winds up and punches the opponent. It's easy to stop him during the laugh or the wind-up, since they both take a while. But if he does manage to land the move, it's an instant K.O.
Thwomps get upgraded to this in Super Mario Galaxy and its sequel; getting smooshed by one is fatal no matter how much health Mario has remaining.
Pouncers could one-shot Wario in the first Wario Land game, regardless of powerup state. Even if you merely bumped into its sides. This is because the sides and bottom were spiked, and spikes were an instant kill to Wario.
Capcom's Resident Evil 4 and Resident Evil 5 have various one-hit kills of two kinds, one from regular game-play or one from quick-time events. One-hit-kills during regular gameplay may result from the player-characters getting decapitated by enemies equipped with a chainsaw, impaled by a Garrador's Wolverine Claws, or being eaten by creatures like mutated alligators (exclusive to RE5) or salamanders (Del Lago in RE 4). Failures for quick-time-events frequently result in deaths for the player characters.
The earlier games had Neptune, who would swallow the player whole, the Hunters, who could decapitate the player, and Nemesis, who could impale his victims through the head, among others.
The Lancer assault rifle has an underbelly chainsaw capable of one-hit kills. Gears of War 2 however has an added quick-time event should two people lock themselves into a "chainsaw duel" and victory is achieved by the person mashing the melee button the fastest.
In both games, sniper rifle headshots, torque bow shot impalements, and Boomshot (grenade launcher) direct hits all are one hit kills.
In the third installment, there is the aptly named "One-Shot." Hit an enemy anywhere and he turns into chunky salsa.
The WidowSniper Rifle in Mass Effect 2, with enough upgrades, leveling up, and the right armor, can regularly do this to most enemies as an Infiltrator Shepard, even being able to kill Harbinger in one hit.
The M-920 Cain heavy weapon, informally known as a "nuke launcher." On Insanity it will still kill most enemies in one hit, in a very large blast radius, and it will probably kill you for the same reason. And it still won't do very much damage to the final boss, who (if you're really unfortunate) will be moving around too much for you to easily hit it anyway, especially considering that the final-boss area doesn't really have a whole lot of walls for you to just aim the Cain at and hope for splash damage.
Moreover, enemies in both games still die instantly if they get knocked into areas that enemies cannot walk on (e.g., chasms). And thankfully Geth Rocket Troopers can't one-shot you on Insanity difficulty like they could in Mass Effect 1.
Mass Effect 3 introduces the Banshee, Phantom, and Brute, elite units capable of soaking tons of damage and dishing out just as much. All three have some form of instant-death attack that will end your game on the spot (although this only applies on harder difficulties). This is particularly aggravating in multiplayer, as the instant-death attacks prevent you from being able to be revived, which can end a game in very short order.
At the end of Priority: Rannoch, getting hit by the Reaper's laser is an instant kill.
ME3 also introduces the Grab, where you pop out from behind cover, grab a nearby enemy, and stab/pound them in the face. Only Armored troops (and the Phantoms) can avoid being killed by the attack (you used to be able to do this to Geth Pyros, but that's been taken out). It's a bit situational, but there are multiplayer levels where you can funnel them in such a way that it's almost like they're waiting in line for you to pull them over and smash their faces in.
In Saints Row 2 you can grab anyone within melee range into a headlock, then hold them as a meat-shield or deliver an instant execution. (Or you could let them go, but where's the fun in that?)
Melee attacks in the Campaign mode of Transformers War For Cybertron are a one hit kill (insert your own justification - Energon blades disrupting sparks or whatever). The downside is missing leaves you completely open, and actually getting into melee range is a dangerous prospect what with all the bullets and the Frickin' Laser Beams.
The PS2 version of Transformers had a minicon which gave you the headshot ability. OHKO to mooks, 3HKO to the Heavies.
The right combination of buffs can grant these, though certain archetypes have an easier time doing it.
Blasters need only combine their Build Up, Aim, and Sniper attacks. Though it should be noted that this will only work against "minion" enemies, or "Lieutenants" who are lower level than the blaster in question.
Stalkers need only perform an Assassin attack while Hidden.
Scrappers can do this with a well-timed critical hit.
In Sengoku Basara, Shimazu Yoshihiro has a Super Skill that will kill any enemy in one hit, whether they be ordinary mooks, bosses or giant robots. Date Masamune's TESTAMENT, when charged for exactly 6 seconds, comes close.
In Space Invaders Infinity Gene, the Classic weapon (modeled after the cannon's design from the original game) first a single laser that can kill any normal mook and most sub-bosses with a single shot. To keep this from being a total Game Breaker, the Classic cannon can never be upgraded, and is next-to-useless against the Final Boss.
In Joe Danger, the horizontal red bars will violently knock you off your bike anytime you make contact with them. NO. EXCEPTIONS. It doesn't matter how many times the game's liberal application of physics have allowed you to land in ways that are physically impossible for someone on a motorbike, if even the slightest part of you touches the bar, you are sent flying. While other objects in the game will also send you flying at the slightest touch, they tend to be more noticeably dangerous; nobody expects to survive landing on a spike strip or giant mouse trap.
Other objects in the game are randomly given the same instant death property as the horizontal bars, but they exist in hard to reach areas as Insurmountable Waist Height Fences.
Assassins from Monday Night Combat have some rather nastyBack Stab techniques with their bladed weapons. It's not strictly speaking a One Hit Kill, but the target's still helpless to do anything about it.
Puzzle Quest 2: Two boss enemies (The Yeti and the Iron Giantnote not that one) have Crushing Kill, which deals 999 damage (more HP than all but the most dedicated level grinder will have). The final boss has Subjugation, which makes the player instantly surrender the fight, winning or losing.
Dragon Quest has the "Whack" spell which may cause instant death to an individual enemy. Its advance form "Thwack" can affect the whole group, but has a lower probability of working.
Certain opponents in Punch-Out!! have special attacks that can knock Little Mac down instantly. Bald Bull, for example, has his powerful Bull Charge .... which can be countered to knock him down instead. In fact, Little Mac can also knock down (or even out) his opponents during key circumstances.
Gotcha Force features several. The most potent is the Ultimate Cannon, which will one-shot anything that gets nailed by it. One of the harder stages in the game involves taking out six in a single level (which also features Arrow Ninjas that can anchor an opponent in place). Anyone nailed with a missile from the ICBM Tank or the Death ICBM also will get taken out in one shot, although those are easier to evade. These methods are distinct in that they are the one exception to friendly fire being Scratch Damage - friend or foe, these attacks will finish anyone hit by them.
In the Thief series, human enemies can be instantly knocked out with the blackjack, instantly killed with the sword/dagger, or instantly killed with the broadhead arrows if shot in the head or chest. In order to do this, however, they mustn't be alert.
EverQuest has three player-usable insta-kill spells: Disintegrate (destroy target), Banishment (destroy summoned target), and Banishment of Shadows (destroy undead target). Usually regarded as Useless Useful Spells because they are often resisted, unusable on higher-level creatures, expensive to cast, and deny rewards for the kill.
"Romanov Attack Satellites" will fire out a deathray below that fries your tank instantly. To avoid death, keep firing at it to push it away so that it will not fire its laser while moving towards you.
"Shovak Bulldozers" are advancing mooks of doom that kill you if you brush against one. To avoid death, you have to push them away by constantly firing at them.
On the bright side, your character has two- Nukes will kill all regular enemies on the screen, and the Megalaser will do the same.
In Red Dead Redemption, the two sniper rifles will usually kill any mook in one hit if its in the head or chest area. Also a headshot with any gun will do this too. Not to mention the throwing weapons always kill whatever they hit.
In the eighth level of the first game, the propellers in the lower end of the ship's stern can kill the characters instantly upon contact. They can only be disabled for a limited time, and it's the reason why getting the Jiggy behind them is called That One Sidequest.
Also in the first game, but in the last level, the eponymous characters play a quiz game. Failing to answer a question on the green-eyed skull tiles will send them to the lava automatically, and they will die.
In Banjo-Tooie, the sequel, the characters are crushed by a ton of iron if they lose during any of the three rounds of the Tower of Tragedy minigame.
In Conkers Bad Fur Day, some hazards and boss attacks are deadly if the eponymous character isn't equipped with something (i.e. being inside a tank or having a space suit). The propellers in the passage leading to the Uga Buga level, the rotating chainsaw from the Experiment, and the tail slash from the Alien are signature examples. The silver gun's shots, any Boom, Headshot hit, the chainsaw, and the katana blade all have this effect in multiplayer as well. The bazooka is this in both multi and story modes.
In Donkey Kong 64, some dark places house searchlights that try to illuminate your character. If it happens, you'll have one second to escape before a sniper rifle shot kills you instantly. Most of the time, death ensues.
The fourth boss in that game, Puftoss, has a surprising one-hit-kill move. During the second and third phases of the battle, he uses a giant blue shockwave that spreads over 80% of the arena which instantly kills Lanky if it hits you, forcing you to redo the entire battle all over again. As a result, despite the more generous time and less varied attacks, the second phase, following a deceptively easy first phase, is enough to turn him into a Goddamned Boss because of how close the checkpoints are to him and how often he uses that lethal shockwave. During the third phase he uses it less and thankfully in the final phases, where there's limited time, he doesn't use that. It's especially noteworthy because not even Mad Jack or K. Rool have an attack that lethal. The only other instant deaths in the game come from falling into a bottomless pit, falling into lava, or falling into the toxic waste in Creepy Castle.
In Castlevania: Order of Ecclesia, the Death Ring dramatically increases physical and magical power, but any hit will kill you. It's the best way to get Boss Medals, since you need to take no damage/take no hits to get them anyway.
Emissions in STALKER Clear Sky and Call of Pripyat. They are one-hit kills, except in Call of Pripyat if you have Marked by the Zone achievement (Survive emission three times without taking cover, it's possible with special pills called Anabiotics) and enough health, but even then, it will leave you with just 2-3 bars of health, and you will pass out.
More mundanely, headshots will kill most human enemies with one blow. The RPG and Gauss Gun take this to the next level; they will kill almost anything in one hit. Good luck finding ammunition, though.
The demonic black Smiles during the boss battle of the sixth chapter. In fact, six of the seven Smith members die inevitably because of them. Luckily, Garcian then grabs the ultra-powerful Golden Gun to kill the remaining Smile, as well as the boss himself, in one shot each. From there to the end of the game, he can kill with one shot any Smile (except the final boss, though it still goes down after five shots), without even having to aim at their weak points.
Sort-of-examples from the Unionseries: Jihadnote Crusade in the English versions, Rivellion*
Angelic Thunder in the English versions
, Judgment Zero*
provided only the unit head is alive
, and Megiddo. While they don't immediately destroy the enemy unit, they are unblockable and result in an instant victory for the Clash they're used in. Jihad and Megiddo also come with damage bonuses.
Melee Warriors in Dragon Age: Origins – Awakening can learn a move called "Peon's Plight", which is an instant kill against generic mooks, does a double Critical Hit against elites, and a normal critical against bosses. Very useful for thinning out the herd, and an absurdly easy way to get the "Heavy Hitter" achievement (main character does 250+ damage with one attack).
Origins gives Mages the spell "Mana Clash," which will instantly kill any enemy Mage or demon of less than Boss level (and some of the Bosses, if cast with boosted Spellpower). And it's an area of effect attack, too, so you can clear out whole rooms full of enemies.
The LBX/20 shotgun in Mech Warrior Living Legends will one-hit-kill any jet fighter in the game if enough of its pellets hit the plane. The Long Tom Artillery Piece, carried by only one unit in the game, will one-hit-kill anything lighter than 50 tons with a direct hit, and near-misses will kill light mechs and hovercraft. While the LBX is horrendously effective versus other targets, the Long Tom suffers from a massive minimum range *
unless the artillery tank is parked on a hill, it cannot aim low enough to hit anything within a hundred meters
, a painfully slow reload time, a pathetically slow engine, and a total lack of support weapons.
Two toys in Guardian's Crusade, Draken which does damage equal to half current hit points to everyone, and Versius, which doubles all damage. Sure you take it too, but if you keep an odd number of hit points, the rounding will save you. Doesn't work on the final boss though.
In Civilization, it can take a lot of time and trouble to conquer a city, and even more to destroy one. Unless you're playing Call To Power and have an Eco Ranger unit to hand; it will completely remove a city from the map in a single hit.
In Nomad (AKA Project Nomad), all space combat is done with missiles. The most powerful missiles are the Phelonese Quietus missiles capable of destroying any ship (except for 2) with a single hit. They're also the most expensive (relatively, as the trading system in the game is of the barter variety) and can only be purchased from the Phelonese. It should be noted, though, that the missiles alone don't guarantee victory in a battle. The victor is usually whoever has the best systems and faster reactions. You might have a dozen Quietus missiles, but the enemy has better targetting sensors and missile loaders, meaning he can put two missiles into your ship before you have a chance to fire your (slow-loading) Quietus missile.
In Mutant Mudds, there are swinging hammers on the fifth and final set of levels that will smash you into the foreground when they hit, instantly killing you.
While any enemy can potentially instantly kill you in Ghost Recon: Advanced Warfighter, the Hard difficulty boost their accuracy and has them always aim for the head, greatly increasing the chance.
Certain bosses in the Tomb Raider franchise can do this: Puna in III attacks with instant-death lightning, although it can easily be dodged, and the Final Boss of the same game will shoot an undodgeable instant-kill fireball if it gets in range. In the games where it appears, the T-Rex can swallow Lara whole.
Anything with the "deadly" adjective in the second, as well as the "dead potion".
Unlimited lets you edit most items directly — giving an object the "dead" or "gone" adjectives will poof them right out of the world.
In the online game Bearbarians, abusing the combo rules and an A.I. Breaker (or just being really good at hitting and running) can lead to your previously low to moderate damage getting stacked up high enough to insta-murder your opponents in a single blow. Combos increase your damage by 1 per consecutive unblocked hit, so a 50-damage attack becomes 51, 52 and so on, but are broken when an opponent successfully blocks. If you can find a location where the AI has to jump up, which renders it unable to block, carefully timed mashing of the attack button will allow you to stack up ridiculously long combos, leading to completely insane raw damage. 1000+ damage per hit will instantly massacre even the most durable opponent. Doing so while holding the enemy flag in a Capture the Flag match will ensure that the battle doesn't necessarily have to end until you develop carpal tunnel syndrome, fall asleep on the keys, or level up while standing atop a gore-soaked platform with more than 600 kills in just that level.
In Rosenkreuzstilette Freudenstachel, you get Kopiekreisel from Trauare, which, if used on Count Michael Zeppelin in the first Fortress stage, is guaranteed to land a 1-hit kill on it for sure. Then again, it works a lot like the Top Spin weapon from Mega Man 3.
In Sluggy Freelance, the talking sword Chaz can kill pretty much anything with a single swing. The only limitations shown are that, for certain creatures, a specific part of the body must be hit, and that Chaz only has this power after bathing in the blood of the innocent.
Later, 4U City's military is shown using weaponized teleporters which transport whatever they hit into Another Dimension. Not really a one-hit kill, but definitely a one-hit victory.
The Golden Arrows from Slightly Damned tend to take football sized chunks out of their targets. It's not a guaranteed kill, but it's pretty close.
SCP Foundation: SCP-544 perceived threads extending upwards from the heads of others, as well as from other living things, and could kill anything instantly by cutting its thread with his mind.
Season 1 of Red vs. Blue has Donutthrow aplasma grenade and oneshot Tex, who was halfway across a canyon and in a tank. This gets a Call Back in season 10, where he manages to lob three plasma grenades in one throw to kill three soldiers.
Avatar The Last Airbender gives the impression that the advanced Firebending ability to shoot lightning is a One Hit Kill if it manages to get a direct hit. This is offset by the difficulty of shooting lightning in the first place (it requires a mindset which is opposite to the usual for Firebending, and insufficient skill is likely to cause it to explode in the users face), and even when mastered the time it takes to build up the charge tends to telegraph the attack.
In the grand finale, Aang's use of 'Soul Bending' borders on a peculiar sort of Have-a-Heart instant neutralization. Ty Lee was feared enough for her ability to -temporarily- kill someone's Bending. Not a 'kill', but in a world where children can throw fireballs it leaves you pretty helpless (Various big name mundanes aside)
Though Ty Lee's ability to "kill" someone's Bending is notably a multi-hit attack and has been stopped mid-process on at least one occasion during the show.
Even without the Elements, a Circle of Friendship attack has enough power to One Hit Kill a trio of Windigos, powerful monsters capable of causing a world ending blizzard.
Let’s not forget about the combined powers of Mi Amore Cadenza’s love and Shining Armor’s shield. One blast is enough to purge Canterlot of the changeling infestation. That would count as a One Hit Poly Kill. Again no Elements of Harmony were involved.
It is not a per se kill, but the pain from a good hit can be enough to leave an un(der)conditioned novice brawler hurting too bad to continue fighting even if he is not outright knocked out.
There is possibly a phenomenon where the right type of blow can produce hydrostatic shock, however the jury's still out on whether or not its real.
Martial arts mysticism aside, chances of an instant knockout are significant if any highly trained fighter is given a reason to go all out against an opponent with little or no conditioning. Even if the attacker has no training, (un)lucky hits can lethally aggravate a pre-existing condition (aneurysms are particularly infamous) and kill in short order.
It is very possible, if very rare, to cause someone to go into fibrillation (heart beating so rapidly and without any rhythm, such that it doesn't actually pump any blood) simply from hitting them in the right place, with the right force, at the right point of a heartbeat. It doesn't even have to be a hard hit. It is unfortunately common in athletes. One minute they're active, then they get what seems to be a hard bump to the chest, and then they're down and out.
Of course, CPR and defibrillation, as well as quick medical treatment has a chance of bringing them back. But for all intents and purposes, until their heartbeat goes back to normal, they are dead.
It is notable, however, that the fatality level of guns is greatly exaggerated in the media. In one study in California, 80% of patients who were shot survived, though interestingly, the number of gunshot wounds in a patient was not predictive of outcome - people with one gunshot wound were as likely to survive as those with multiple gunshot wounds. Even more unexpectedly, a mere 40% of people with gunshot wounds to the head died - meaning over half of people who get shot in the head, live.
Most weapons, on the other hand, can easily kill with a single hit. That's what they're for.
The weapon wasn't used on him, though. It was used on a couple of nearby localities and he just happened to have the "good luck" to survive. If he had been the target of a nuclear weapon, and his location known and the bomb dropped right on his head, the U.S. Air Force would have certainly claimed victory.
Hell, if you're dropping something the size of Fat Man or Little Boy directly onto somebody's head from the height of an airplane, it doesn't even have to explode to kill them. Hitting that small a target is another story, but if you can hit, the whole several hundred pounds moving at terminal velocity would probably do the trick. (The modern military actually uses inert concrete bombs of about the same size to obliterate target buildings with minimal damage to the surroundings.)
Project Orion would suggest that a properly designed structure can survive hundreds of nuclear weapons.
They were planned to be 0.15 kilotons and the pusher plate wasn't so much as "structure" as "a huge chunk of metal with some shock absorbers behind it".
Correct on the latter, though the pusher plate also had to have such things as the bomb delivery system running through it as well as a retractable shield to keep it intact. And the final version of Orion would have used 35Kt thermonuclear shaped charges converting a plastic substance into plasma (as well as part of the bombcase) and using the impact of that plasma as thrust. Yes, that's right, ''thermonuclear shaped charges.''
Box Jellyfish isn't really that bad. Many persons survive the sting every year. But the sting of Chironex fleckeri is always very painful, and if you don't get killed in the first fifteen minutes, you are likely to survive. [Though the pain is so intense you wish you were dead.] The girl in the article was lucky because she was stung in a really nasty way - she should, by all means, have died with that amount of venom.
Of course, after living on a continent of death, hopefully Australians have started to evolve just enough to survive the types of instant death their land and seas so famously have in abundance.
Not much you can do to develop a resistance to being stabbed in the heart.
The poison dart frog poison kills even faster; less than 3 seconds; it has to get in the blood though, so contact itself probably won't kill you.
Unless it's the Golden Poison Dart Frog, which can.
In naval warfare, a well-aimed or lucky hit in the opposing ship's magazine can lead to that ship being blown up by its own ammunition. This is what basically happened to three British battlecruisers at the battle of Jutland in 1916 and to the HMS Hood in 1941. Similarly, hydrogen-filled Zeppelins in World War One were easily downed with just one burst of incendiary ammunition and a number of World War II planes were quite vulnerable to hits in their fuel tanks, most notoriously the Mitsubishi "Betty" aka the "one-shot lighter" or "flying zippo".
And even when the shot is not on the magazine, if it hits the rudder, the ship is a sitting duck, effectively destroyed. Case in point, the Bismark.
This can also happen with torpedoes. Specifically, a magnetic (or other proximity) torpedo detonating a short distance below the keel of a vessel has the potential to "break its back". Causing the ship to split in two and sink relatively rapidly.
Hell, it doesn't even have to be in the main magazines! At least one of the hits at Jutland was a turret hit, which wouldn't have been a problem except that the Royal Navy battlecruisers' gunners were bypassing safety protocols for the sake of rapid fire and leaving a nice, flammable chain of cordite leading all the way to the magazines. That, and the fact that the cordite stock hadn't been sufficiently rotated and the stuff was a bit old and chemically twitchy, added up to cause disaster.
It doesn't even have to be the magazines: in World War I the SMS Szent István was torpedoed in the aft boiler, killing the power needed to use the pumps and throw the water out. In fact a direct hit from a well-placed torpedo will sink most warships, with only the biggest capable of surviving.
Masutatsu Oyama, founder of Kyokushinaki Karate, was considered in his time the embodiment of "One Strike, Certain Death". Three times in exhibitions, he killed a full-grown bull with a single punch.