In video games, this is a high-risk/high-reward attack that, if it connects, it hits For Massive Damage. But if it misses, you either are going to eat a painful Counter Attack or will have crippled yourself in some other way. The penalty is much more significant than just wasting the move.
Can also apply to attacks with long wind-ups that open the player up to counters.
Can overlap with Desperation Attack, but these can be done at nearly any time. Can become a Game Breaker if the success rate is too high or Awesome, but Impractical if too low. Scrubs usually hate these. Some kinds of Alpha Strike may also manifest as death-or-glory attacks.
For an even more extreme version, see Suicide Attack. When this applies to an entire character, it's a Glass Cannon.
The Trope Namer is the Death or Glory move from Warhammer 40000, a called maneuver in which a model stands in the path of a charging enemy vehicle to squeeze a good shot off. Success means one-shotting a large enemy tank. Fail: you go squish.
This is referenced in Dan Abnett's Gaunt's Ghosts novel Necropolis, where the civilian militia resorted to sending men with demo charges to destroy the advancing Chaos tanks. When a Guardsman found out about this tactic, it resulted in the following conversation:
Guardsman: How many tanks have you destroyed? Militia: Twenty-four, I think. Guardsman: How many men did you lose? Militia:(shrugs) Twenty-four, of course.
All-Out Attacks in GURPS are variously more accurate or more powerful than normal attacks but they leave you unable to defend yourself immediately afterward.
A large number of feats and combat styles in Dungeons & Dragons, at least in the third edition, is centered around lowering your stats for extra damage. The classic one would be Reckless Offensive, a feat that allows you to trade armour class for extra accuracy on your strikes — another one would be Robilar's Gambit, a feat that lets you counter-attack anyone who melee attacks you that round in return for a greatly reduced armour class.
The Bravura Warlord has a lot of moves like this, though it also encourages your buddies to do so too.
Almost every advanced combat maneuver in the Old World of Darkness Storyteller System requires the user to forego their defense, leaving them with only their armor. Of course, since one of these combat maneuvers allows you to punch one opponent four times in a single round, defending yourself might not be too much of an issue.
Exalted The peak of the Wood Dragon Terrestrial Martial Arts skill tree is a Charm that will kill anything that is alive, if it hits. The problem? If your attack failed to hit, at the end of the duration of this Charm you die. This is not a setting where Death Is Cheap.
The priests of Kor, the god of war and slaughter in The Dark Eye, have the power to harness all the damage their first eight strikes would do and use it all on the final ninth strike. While they are doing this, they will start counting from one to nine, so any enemy familiar with this cult will know what's coming.
In a Star Fleet Battles ship-to-ship duel, firing an Alpha Strike in a "narrow salvo" (all weapons are resolved with one die roll, so either they all hit or they all miss) is likely to either cripple your enemy or leave you highly vulnerable until you can reload (if you survive that long). The tactic is less risky in fleet engagements where ships can cover for each other.
Fairly common in BattleTech - especially the "Classic" era. Very few 'Mechs can fire all their weapons at once without raising their heat level to a point where the 'Mech is very likely to shut down.
Battlefield 2's sniper kit could get into some interesting showdowns with jeeps. Any time a jeep driver sees infantry out in the open, there's a decent chance he'll try to run them over. If the sniper is feeling bold, he can stop, take aim, and kill the driver with a single flawlessly aimed headshot, bringing the jeep to a stop. If he misses, it is incredibly unlikely he'll have time to get clear before being run down, much less take another shot.
Sometimes if the sniper kills the driver too close to himself, the jeep does not have enough time to come to a full stop and it smashes into the sniper anyways. Due to a somewhat buggy kill scoring system, the driver may or may not get credit for the kill.
Similarly: The C4 packs. If you manage to stick a few of them to a vehicle and detonate, you have a guaranteed kill. Of course, this requires you to be in close range of a tank (which will kill you pretty much as soon as one of the occupants notices you) or a jeep (where either machine gunners or getting run over will kill you). Against infantry they are also like mines or grenades you can control, but holding the detonator leaves you completely defenseless if they see you. Not to mention the high chance of getting caught in the explosion yourself.
Battlefield 3 adds "Jihad Jeeping" to the above mix; shove some C4 on your Humvee/UAZ, drive headlong at an enemy armoured vehicle and hope you can time your dive from the moving 4x4 so that it still has enough forward momentum to hit the target without you getting caught in the explosion... unless you don't mind having to respawn, in which case it's a Suicide Attack.
Reach has the "If They Came To Hear Me Beg" achievement. To get it, you must assassinate something while falling from a height that would have killed you. If you succeed, you get the achievement and survive (the assassination breaks your fall). If you fail, your target gets to see your body slam into the ground next to them.
S 4 League's melee weapons are pretty well made of this trope. The storm bat, plasma sword, and counter sword are all extremely powerful and stylish ways to put an end to your enemy - but after completing a combo they leave the wielder horribly exposed for about two seconds, an eternity in a fast-paced game. If you miss or if your target has backup, you probably will not survive.
In Puzzle Quest: Galactrix, the Bola Mine attack can one-shot lesser opponents and severely damage more powerful ones. But since the placement of mines is random, it can also leave your opponent with a board full of mines to hit you with. (Especially if your opponent also has Bola Mine). The Deathbringer spell in Challenge of the Warlords works the same way.
Instant Kill Moves in the Guilty Gear series. Connect - it's an instant KO. Miss - your super bar is gone for the rest of the round.
In the first game, when the opportunity to input the IK arises, the opponent can race to input a "counter" command or even the same IK motion, possibly eliminating the instigator instead. In the same game, IKs win the whole match instead of just one round.
Several characters in Tekken have these. Most are telegraphed attacks with ridiculously long windups:
Possibly the most interesting is Yoshimitsu's reverse hara-kiri: He takes a step forward, turns to face the opposite direction, and stabs himself in the stomach. It deals massive damage to him and, if it connects, even more to his opponent.
The Devil/Angel beam. It will erase half your opponent's life bar, but has such a long wind-up that most human players and higher-level CPU players can position themselves for a severe counterattack.
Paul's straight punch comes to mind. Amusingly though, the slight lean backwards as he winds up made it possible to use this as a dodge/counter against someone who was trying to land a ridiculously powerful attack on you, which generally resulted in a confused and/or enraged opponent pausing for a half-second before being blasted across the screen.
Jigglypuff's "Rest" attack and Luigi's "Super Jump Punch" can both easily inflict a One-Hit Kill, but only if they are used at absolutely point-blank range. Otherwise, they inflict Scratch Damageat best. Jigglypuff's Rest also puts it to sleep for about two full seconds (whether it connects or not), and Luigi's Jump Punch is also his mid-air recovery move, which makes it risky to use anywhere that isn't above solid stage ground.
Toon Link's downthrust aerial attack sends him plummeting straight down, sword first. The attack is a very powerful spike, but like Luigi's Super Jump Punch, if you don't have solid ground to land on, you could be giving yourself a one-way ticket off the stage.
Captain Falcon'sFalconPUNCH! has a long windup period (almost one full second) before it strikes, making it easy for a player to avoid or interrupt it. (But if it hits....)
Ganondorf's "Warlock Punch" is actually stronger than Falcon's Punch, but requires even more time to execute before it hits. Either one is easy to mess up if against a skilled opponent , but this is what happens when you succeed in connecting the attack. The same happens with his Vulcan Kick. Again, it does a lot of damage and can kill very early. It has the longest charge of any one attack (88 frames in the NTSC version, so about 1.5 seconds), though, and Ganondorf's completely immobile during it.
Marth and especially Roy from SSBM. Their B-button attack (when held down) is a charged sword strike. Marth's is quicker and not quite as powerful as Roy's, but it can KO an opponent if they already have decent damage. Roy's takes a ridiculously long time to power up, and if used at FULL POWER, can instantly KO pretty well anybody. AND Roy takes 10% damage upon using it. Of course, the move is pretty strong when not at 100% power, so usually you can get it up to 80% and KO a damaged opponent.
They also have a Counter attack. When you trigger it, Marth/Roy takes a pose. If he's hit before the pose is over, he counterattacks. Marth has a longer pose, but a weaker counter; Roy's counter is absolutely devastating, but takes a lot of timing to pull off. Naturally, if you mistime the pose (or your opponent grabs you instead of hitting you), you're going to eat the biggest attack they've got the moment your pose ends.
It's quite fun when somebody else has a hammer and you run up to him and counter it.
And in Brawl we have Ike, who combines Marth and Roy's charging attacks and counters with slow, Ganondorf-style attacks. His entire game is about timing and distancing, and if he gets them right, the game will be very, very short.
Hammers have become this. Melee started the tradition with the normal hammer losing its head, becoming a useless piece of wood - by the time you're done flailing a stick around and don't know how to stop, someone else will have already picked up the head and thrown it at you (or, in three-fighter matches, someone else), or just taunted you for ten seconds at making a fool out of yourself. If you're unlucky enough that you're in a place where you need to double jump or higher to get out of there, a Roy or Ike user may have just dropped down and hit you with his B attack. Brawl has it even worse; if someone picks up the shiny new Golden Hammer, run, bitch. One hit - two at absolute optimal conditions - and you will be eliminated before you can say squeak... assuming the hammer doesn't beat you to it.
In most American football video games, calling an all-out blitz can result in nailing the opponent for a big loss. A successful blitz can swing a game's momentum in your favor. If you can't reach the ball carrier, it can swing the other way, as it leaves large gaps in the defense and plenty of uncovered players to act as blockers.
The best examples are Fissure, Guillotine, Sheer Cold and Horn Drill. They only have a 30% chance to hit, but if they do, you opponent is one-shoted. Fissure, being a ground type move, suffers from Flying types and Levitate and Air Balloon users being immune, but otherwise, landing one of these WILL knock out an opponent's Pokémon. If you miss(70% chance), you just gave your opponent a free turn, which can prove devastating. These three moves are banned from competitive play.
"Hi Jump Kick" hurts the user by one-half of the damage it would have inflicted if they miss. In an early Battle CD from Gale of Darkness, you actually have to use this to your advantage - the opponent is ridiculously powerful and can knock you out in one hit, but the fixed pattern of attacks - it uses three elemental punches, then High Jump kick, and you have a Blissey (who has a silly amount of HP) with a move that blocks any attack, but loses its chances of success with repeated use - means a single blocked attack is all it takes to finish the foe.
In Generation V, the damage from missing is changed from one-half the damage it would have done to one-half of the user's maximum HP. Probably because of the above scenario, and a boost in its base firepower (to 130, after already being boosted from 85 to 100 in Generation IV).
Ghosts can use Curse to inflict an incurable status which can eat through the foe's hp frighteningly quickly. The downside is that the user takes a nail to the eye for 50% of its health bar, making it rather easy for the enemy to finish the job (but making it harder to catch wild Ghost Pokes that use it, since they tend to pass out).
Several attacks require two turns to execute. Sadly, they're rarely powerful enough to make up for wasting the first turn (Razor Wind, Skull Bash). Then there's Solar Beam, which doesn't need a turn to charge if the weather is sunny, though causing sunny weather takes up a turn itself and if your opponent is faster and changes the weather, you're boned. Then there's moves where you're semi-invulnerable the first turn (Dig, Fly, Dive), though there are always a few moves that can still damage you (as well as a few that will cause extra damage (Earthquake against Dig)). None of those two-turn moves are very popular in competitive play, simply because the opponent will be able to switch to a Pokémon that resists or is outright immune to the attack, and has a good chance of being highly capable of mopping the floor with the two-turn-move-user (the exception being Gyarados's Bounce and Origin Forme Giratina's Shadow Force, since both Pokémon are powerful enough to justify the use of such moves).
Hyper Beam (and its many variants, like Rock Wrecker, Roar of Time, and Giga Impact) are inversions of the usual two-turn attacks: They strike first and require a recharge turn later. They inflict massive damage, but the extra turn required to recover it can prove fatal in fierce competitive settings. (On the other hand, the extra turn is a moot point if you're about to get KO'ed anyway...)
And there are moves which sharply reduce the user's stats after use, which can make your Pokémon practically useless afterwards (e.g. Draco Meteor and Overheat sharply reduce attack power after use) or vulnerable to enemy attacks (Close Combat, which reduces defense).
Then there's Bide. For two turns, your Pokémon doesn't do a thing. On the third turn, he'll attack, doing exactly twice as much damage to the opponent as the opponent did to your Pokémon during those two turns. Unless your Pokémon hasn't taken any damage because your opponent was too busy buffing its own stats in order to be more able to crush you. Or it did crush you before you could strike back. Or your Pokémon is suffering from confusion or paralysis or something similar and quite simply fails to use the move. Pokémon seriously loves this trope.
There's also the recoil damage attacks (Jump Kick and Hi Jump Kick not included, since they do a different kind of recoil damage), which do damage to the user whenever it hits. And they all do pretty good damage; none of the 8 that a Pokémon can learn naturally have a power lower than 80, 5 of them have a power of 120, and one has a power of 150. But the damage they do to the user is pretty hefty; all but one of them does 1/3 of the damage its user dealt, and the other one, Head Smash (the most powerful one), deals half the damage the opponent took. Imagine how much Rampardos (who has the second highest base Attack in the game, beat only by Attack Forme Deoxys; oh, and he also gets a 50% damage increase since Head Smash is a Rock attack and Rampardos is a Rock Pokémon) is hurting after using it.
Head Smash becomes Awesome Yet Practical if you've got a Relicanth with the Rock Head ability (Relicanth learns the move VERY late at level 78), which gives you a super-powered attack with NO drawback other than 80% accuracy. Aggron, the Steel/Rock Triceratops, can learn Head Smash as an Egg Move from Rampardos, and it also has Rock Head, making its 110 Attack stat and STAB far more dangerous.
And then there's Normal-type Struggle, which is used by Pokémon who've run out of PP for all their moves. On the plus side, it ignores the opponent's type, so you can still use it on Pokemon that resist or are immune to Normal attacks. Unfortunately, the recoil damage is pretty hefty: as of Generation IV, the user takes damage equal to 1/4 of their max HP every time it hits, regardless of how much damage it dealt.
Shadow End from Pokémon XD. It's powerful (120 power Shadow move, doubled to 240 against regular Pokémon), but the user's current HP is cut in half whenever it hits. That, and a base accuracy of 60% make it less reliable than Thunder or Blizzard.
Zap Cannon. 100 power (120 in Generation V), instant paralysis, but only 50% accuracy. Dynamic Punch is the same, only it's Fighting-type and confuses. Pokemon Black And White also gives us the move Inferno, which is Fire-type and causes a burn. Focus Punch is a 150 power fighting move, but goes second and fails if the user is hit.
When used on its own, Focus Punch is practically useless outside of very specific circumstances. As of Gen V, we have the move After You... Granted, this only makes the move a lot more reliable in double and triple battles.
''WorldOfWarcraft'' has a villainous example. Icehowl, a gigantic yeti fought in the Trial of the Crusader raid, has an attack where he scatters and stuns the raid against the walls, then targets a person and charges him/her. If the target (or anyone else) is hit by the charge, Icehowl goes into a rage and gains a massive damage and speed buff. If he misses, Icehowl crashes into the wall and is stunned himself for several seconds, and he takes double damage from all attacks. Considering his massive amount of health, you want him to always miss if you want to beat the enrage timer.
In World of Warcraft the priest spell Shadow Word: Death deals damage to an opponent, but if it fails to kill them hurts the priest as well.
Desperate Attack in Duel fights in Suikoden - it does a lot of damage, but if your opponent chose Guard in the rock-paper-scissors, you're going to eat a counter. (Defeating Teo with Pahn in the first game, a seemingly Hopeless Boss Fight that must be won to get 100% Completion, is best done by choosing only Guard - Teo eventually flips out and starts using Desperate Attack exclusively.)
Yoshimitsu of the Soul Calibur series has an attack where he stabs himself through with his own sword - akin to ritualistic disembowelment - losing the round, if he kills himself. If it kills an enemy conveniently standing behind him during the stab, however, the round win goes to Yoshimitsu, even if he dies from his own move.
There are also attacks denoted by an exclamation mark on the character's move list. Said attacks are massively telegraphed (with the screen dimming and the character's weapon being covered in flames and Sucking In Lines) and take a while to execute, but deal massive damage and smash right through guards.
In Team Fortress 2, each class has a "taunt" attack that is an instant kill if it actually connects. However, it requires them to stand in one place for several seconds completely defenseless.
Of course, if you can time it just right, you can kill someone coming through a doorway with one of these taunts by standing out of their sight behind a wall. A guaranteed Oh Crap moment if there ever was one.
The Pyro's taunt also has a distinctive charge-up sound and animation. The Spy is similar, although he says a generic line instead of shouting. The charge-ups for the other taunts are silent and usually less noticeable.
Don't confuse these attacks with the Spy's instant-kill backstab or the Sniper's ability to one-shot enemies.
The Sniper's ability to one-shot enemies can be used for a Death or Glory Attack, if you're a good enough shot to stand your ground and blow the enemy Heavy's head off at point blank range instead of running away.
The Sniper's Taunt can actually be useful since it's actually two successive attacks in a row. The first one does miniscule damage, but paralyzes the target for the second half and has priority over every other attack. This is extremely useful if a Demoman is charging your way, as you will literally stop him in his tracks (he can only slightly nudge his direction, but otherwise cannot change his path) and get off an insta-kill if no one else is around.
The Soldier has a weapon (the Equalizer) which does more damage the less health he has. Either you'll kill that Heavy in a single massive hit or you'll die because you're running around below 25HP. Also, taunting with this weapon causes the Soldier to become an Action Bomb, blowing himself up with an otherwise-unusable grenade and taking any enemies nearby with him.
The Scout's taunt kill is perhaps the most rewarding of them all. It takes about 5 seconds to use, the longest taunt kill in the game. He calls a (baseball) shot, Babe Ruth-style, then swings his bat. Hitting someone with this taunt kill in an open area can launch their corpse well over 100 feet, and is hilarious when it happens due to its rarity, and the fact that seeing some guy's body fly clean across dustbowl is hilarious.
In January 2011, an update gave the Scout a new melee weapon to use: the Boston Basher. Hit an enemy with it, and he gets hit hard with an additional bleed effect. Swing it at thin air, and you hit yourself for half as much direct damage and an equal amount of bleeding that can equal nearly half your health.
A Pyro attempting to airblast a projectile at point blank is very difficult—and with a bad connection literally impossible—but if successful will take off a very large piece of his target's health (a Sniper using the Huntsman can even be one-hit KO'd this way). If not succesful the Pyro just lost at least half of his health and may not even be able to attack again before he's finished off.
In Battle for Wesnoth, units with the Charge ability deal double damage when attacking, but take double damage in return.
In Dokapon Kingdom and Dokapon Journey, every character you control or fight has a move called "Strike", which usually does enough damage to bring down a full-health enemy of the same level as the person using it. However, should the character on the receiving end counter it (using a move of the same name), the attacker gets the damage instead. It doesn't necessarily kill, but characters can kill enemies of much higher level than themselves by getting a lucky counter on the defense and then finishing off the opponent with their attack.
In The Legend Of Zelda Twilight Princess, the sword tech "mortal draw" works like this. To use it, you must walk up to an enemy with your sword sheathed, and then press A when prompted during a small window. If it hits, you kill almost any enemy in one strike. If you mistime it, then the enemy gets a free strike at you.
Similarly, facing a certain charge attack from the Final Boss will prompt you with "chance" and to press A, which enters you into a (completely optional) button-mashing Blade Lock event with him. If you miss the "chance" window and fail to get out of the way, then you get hit with the brunt of the attack. If you fail the Blade Lock, he'll take away a chunk of your health. But if you succeed both of those, you're well on your way to killing him.
In the Punch-Out!! series, Bald Bull's Bull Charge will end with a knockdown for one of you. You can try to dodge the attack, but Bald Bull will just reset and keep trying to charge at you until you try to counter him with a punch to the gut. Succeed, and he goes down. Fail, and you go down.
While not quite an attack, in two player mode you can become Giga Mac. You have much more power, but your punches do take longer, you can't dodge anything, and standing still for too long gives your opponent a chance to get star punches. A good opponent can actualy knock you out even when you're in the Giga Mac mode. The two taunts, that replace dodging, could also count - Manage to get the taunt done, and you get a star punch and more time as Giga Mac respectively; Three star punches as Giga Mac give you a One-Hit KO move, and you could theoreticaly carry on as Giga Mac for the entire match with the "Juice" taunt. However, If your opponent mannages to punch you, you lose all your stars, and they either get a star or knock half your time away.
In the Sword Of The Samurai Kenjutsu minigame, there's a "power attack" that causes two hits instead of one (opponents can only take 4 hits in total before succumbing). Unfortunately, it was extremely hard to perform with the lackluster controls, and the AI was adept at blocking them even when performed very quickly.
The Royal Release from Devil May Cry 3 and 4. It can deal awesome, awesome damage to even Dante Must Die bosses. However, you must first build up a meter, preferably by blocking enemies' attacks at the exact moment when they would connect, and then unleash it also when an enemy's attack would connect. Fail to meet the timing and not only is the damage reduced significantly, but Dante also loses the invulnerability frames a successful Royal Release would have. Massive hurt on Dante tends to ensue.
Cr0wning the Witch in Left 4 Dead. Succeed and she goes down in one hit. Fail and you are going down in one hit!
The Tank has the ability to hurl large chunks of concrete at the survivors, which allows him to attack at range for good damage and chance to hit. The animation however takes a whole 3 seconds for lifting and throwing the rock, leaving him wide open for survivor gunfire.
Likewise the Tank's Boulder can be shot out of the air, but it takes a few shots to do so, and unless it's coming directly at you, it's probably better to just run. If it connects, however, it will stun you long enough so that the tank can get to you, so it's sometimes worth taking that shot if you have no other options (or if the tank's a really good shot).
With the appropriate weapons mods and ammunition, sniper rifles in Mass Effect can deal absurd amounts of damage- if you don't mind them overheating after one shot. You're not truly helpless, but you won't be shooting again for a second or two while your unfortunate victim's allies exact revenge.
The Vanguard class in Mass Effect is described as being this, a "high risk, high reward" class that rushes the front lines. In Mass Effect 2, the Vanguard's class ability is Charge, which biotically propels the player from anywhere (with a clear line of sight) to the enemy, ramming into them with incredible force. This can take them out, put a shot-gun wielding player in close- or it could lead to the player getting completely swarmed. It tends to go one way or the other, but this trope really shows when the player intentionally charges one enemy in the middle of an entire group. At higher levels, Charge also adds extra shield protection once it lands; since the shotguns have a tighter spread than in most games, a Vanguard with bad aim will be mowed down quickly. A Vanguard with good aim will splat entire enemy squads after they come out of Charge before their extra barriers fail.
Mass Effect 3: Vanguards keep the 'charge' ability from Mass Effect 2, and gain the 'nova' ability, that uses up their remaining shields to deliver a Shockwave Stomp, making this trope into the Vanguard's specialty. With the right upgrades the Vanguard's charge cooldown is under 3 seconds, allowing them to repeatedly charge/nova enemies to death while remaining nigh-invulnerable to anything short of massed enemy fire or a one hit kill ability from an enemy. Vanguards don't even need to carry a gun by that point.
Dissidia: Final Fantasy has several of these. There are moves to immobilize opponents, instantly cause Break status on them, summon a giant meteor to fall on them, etc. Of course they all require you to charge up for several seconds with no defense for counter-attack. These moves are actually effective against the AI because they're liable to just stand and watch you charge up your kill move, or can be "tricked" in various ways into being unable to do anything about it, usually by exploiting the stage - human opponents know better of course, so don't expect to see any of these moves go off in a PvP match.
The Emperor's Starfall attack became more usable in the sequel, ue to gaining a property that stops ranged Bravery attacks, forcing the enemy to close in on him, which may play into his hand. Meanwhile, Exdeath's Maelstrom is almost never intended as an actual attack, rather as bait to make the enemy try an attack, which Exdeath can counter.
StarCraft has the Nuke. Assuming you can get the Ghost into enemy territory undetected, and he can survive the ten-second call to target the Nuke, and you can afford the time and resources to build the Nuke itself, the Nuclear Strike is guaranteed to kill all units and severely damage all buildings within a considerable radius.
Certain early-game rushes also qualify as this. A player may opt to build a fast unit-producing building (that may be near the enemy base, in the case of Terran/Protoss) and forgo peon production for an extremely early attack. If they're successful, they'll either outright win the game, or at least severely cripple the opponent's economy. If they don't do enough damage or get scouted early, their own economy will likely be in such poor shape from not building workers that they will be way behind on the tech tree, if the opponent doesn't come after them with a fast counterattack to flatten them right away.
In BlazBlue Hakumen has a quite small window for setting off his Counter Attacks. If you're trying to stop a Distortion Drive or Astral Heat, failure will hurt a lot. It does not help that some Distortion Drives and Astral Heats have unusual timing so you cannot just blindly use the super flash buffer technique.
In the two Touhou fighting games: Hisoutensoku and Scarlet Weather Rhapsody, there are many attacks that fit under this trope. The most notable being Reimu Hakurei's "Fantasy Heaven" Spell Card. When activated, seven orbs surround Reimu and with each successful melee attack, one orb lights up. When all orbs lights up... holy crap, you are already dead. In SWR, this move cannot be fully grazed and will do ''massive damage'', in Hisoutensoku, there is no chance of surviving the move once it's activated, even with a full health bar (the move can potentially do 18000 damage, your maximum health is 10000). Sounds good huh? Problem is, the spell cost all your current spell cards, the time is limited, and if your enemy is smart enough to know what you are doing and run away from you during this time, it is simply impossible to activate the move.
Not true, in Hisoutensoku Fantasy Heaven as an incredibly small chance to miss, if your opponent is at the right angle just above, and a little ahead of you, or, if they hit the edge of the stage above you and are in an invincible falling frame, in which case they will likely stand up during the duration of Fantasy Heaven, but will not be killed.
In Dungeon Fighter Online, the Asura class sports Ground Shaker and Agni Pentacle. Both can potentially end any duel should they hit, but if the Asura wiffs, they are left completely immobile and defenseless for a good 3-5 seconds in which time they likely will be killed.
Fate/unlimited codes has "Holy Grail Burst Super Attacks" for each character, which can only be activated when the character enters Burst Mode while 1) their Mana Meter is full, 2) the Holy Grail is full and 3) the player was the one who landed the hit that fills the gauge. If a character successfully connects with one of these, it can cause devastating damage to the opponent. This can be ruined by not activating the skill before the mana meter runs out (in which case you'll have to charge it up again by fighting), or activating the skill and missing (causing the Holy Grail to disappear for the rest of the round).
Wing Commander Prophecy has your ship, the TCS Midway, get a Mid-Season Upgrade in the form of an Alienship-killer gun that your people salvage from the wreckage of an enemy ship and attach to your carrier. The weapon is used once (in a cutscene) to destroy an alien Dreadnought. Due to the crapshoot-quality of all ship-killer Wave Motion Guns in the Wing Commander universe (or at least, the ones the humans try to use), they don't want to try it again unless Plan A (a full-out, desperate assault led by the player) fails. If they are forced to use the gun a second time, you get a cutscene of the Midway blowing itself apart.
In the "Superweapon" mode of the iPhone version of Battleship. you have the Torpedo weapon. It fills an entire column with shots, stopping when it hits an enemy ship. But... If there is no enemy ship in that column, the corresponding column of shots is shifted to your board and any of your ships on that column will take hits.
In several Fire Emblem games, there are Devil weapons. They are extremely powerful weapons that look like handy and valuable weapons at first... until you realize that they will occasionally deal the damage that would have been dealt to the enemy to the user themself! If the Critical Hit animation plays before the attack hits, pray that the enemy will receive the buttload of damage, or...
In Spelunky, killing shopkeeper with a teleporter is like this. If you're lucky, you may kill shopkeeper without alarming other shopkeepers and steal his goods with impunity. If you're unlucky, you may end up in a wall or teleport out of the shop and anger the shopkeeper.
Uplink has hacking a bank. Succeed, you can earn huge amount of money. Fail to cover your tracks, and your account is suspended, in gameplay terms you get game over. Can be turned to Disc One Nuke is player knows wealthy account and how to pull this off early in game.
The "glory" part comes from the second half of the bank hack, if you do it early in the game. The first half, transferring the money to your account, is relatively easy. The glory comes when you use your ill-gotten gains to purchase the programs you need to hastily cover your tracks, along with re-hacking the bank and so on. As it can take literally a few minutes for banks to back-trace your net-link passively, you have to work very fast, and it's awesome when you pull it off. If you don't...
Gunz The Duel has d-style, a fighting style based primarily in countering k-style moves. Most d-style moves require exceptionally good timing, the opponent to be in a specific position or animation, or just dumb luck. It is extremely effective when done right, but most players quit long before they are good enough to do it right.
Castlevania Order Of Ecclesia has two different ways of doing this that aren't even attacks in and of themselves. One is an accessory known as the Death Ring, which significantly increases one's stats while making it so that one hit from an enemy will kill you outright. The other is a buff glyph known as Dominus Agony, with an even bigger boost and a cost of 66 hpper second. Either one (or even both if you're especially daring) is most useful in boss fights, where one of you is going to die in a scant few seconds.
Scarface: The World is Yours: Depositing ill-gotten money in the bank to be laundered requires a 'negotiation' meter. Fail and you lose half your cash in fees. Not that much of a problem when you're chucking in two grand. Later in the game, you're dealing with millions of dollars. It's just safer, in many cases, to hold onto the cash, risk losing it in death and spend what you can on the 'Exotics' menu (which provides other benefits). Drug deals use the same mechanic - if you fail, you spend the same amount of money but get only half the yeyo. If you critically fail, negotiations break down and the dealer's gang attacks you. You also don't get the drugs if you kill him.
Sword of the Stars has AI techs. Researching them gives you massive bonuses. However, every turn spent on research gives a chance that you have a devastating AI Rebellion.
Might And Magic: Clash of Heroes has Fiona's Spider Cloak accessory. It boosts the power of her individual units by 100%, allowing her to take on opponents of much higher levels. The drawback is that it knocks her lifepoints down to 10% of her max, so one solid hit will kill her. Note that in earlier versions of the game, Fiona could refill her life points to full, with the Vampire elite units and a bit of luck. The Steam version closed that loophole by hard capping her HP at 10% of maximum.
Wizard 101 has a milder example with the storm spell Wildbolt. It has slightly less than a 25% base chance (up to a 33% with boost) of causing 1000 base damage, enough damage to kill any non-enemy until about the middle of the second to last world, to a single target for a fairly small cost. However, if it fails it only does a very small amount of damage and uses any boost cast.
In the Gundam video game, Encounters in Space, several mobile suits have an extra special attack, only usable when they fill three bars of the special meter (normal special moves use one bar). After using these abilties, the mobile suit's special meter will "break" and no longer charge for the rest for the fight. The GP02A Gundam "Physalis" fires off its nuclear bazooka, while the two Blue Destiny units activate their EXAM systems.
Ralf Jones of The King Of Fighters has the Galactica Phantom, a super move that can be interrupted with a low attack (it makes him invulnerable to high attacks) and a very long start-up time. If the opponent gets close enough to sweep you, you're in trouble. But... It has a far longer range than it looks, and deals ridiculous damage. Either you're leaving yourself wide open or you're winning the round.
The Sniper Minirobot from Mini Robot Wars. It shoots an extremely fast and damaging bullet at any enemy machine that enters its attack range. The catch is that said attack has a chance of missing completely, and the shot interval time is quite long. If he fails to hit the stronger enemies such as Mega Smashers, you can kiss your defenses goodbye if you don't have a ready bomb on hand.
Thankfully, this gets averted once he gets the Eagle Eye upgrade, which makes all his shots hit no matter what.
Limit breaks in The Last Remnant can be devastatingly powerful, but requires staying in close combat with the enemy. The union will also avoid almost every attack, until the limit break is used. So using these attacks instead of healing while on low health will guarantee a huge amount of damage to your enemy, and then leave you completely open to counterattack.
Last Scenario has the Brutal Attack spellcard, which deals massive amounts of damage, but also damages the user. It's entirely possible for the user to KO themselves if they don't have enough HP to survive it. It's also possible for the user to miss with either the attack or the damage dealt to themselves, which can lead to either the character hurting themselves for nothing, or dealing big damage with no consequences.
Counter Hypers in Ultimate Marvel Vs Capcom 3 have pretty much unbeatable priority and do great damage, but have to be timed perfectly (excruciatingly difficult in Online Mode) and if you fail, you lose precious Hyper meter.
Phoenix Wright is a Death Or Glory character. His entire playstyle hinges on you being able to hold the enemy off until he can gather the Evidence necessary to enter Turnabout Mode, but this is so difficult very few players can pull it off with anything even approaching regularity.
In the Programming GameRoboWar, the "killshot" was a major part of strategy, and was made possible in part by the ability of robots to expend in one turn up to 200 more points of energy on anything than they actually had. By putting enough energy into bullets or missiles, they could at least theoretically be strong enough to kill any opponent, but having negative energy made a robot a comatose sitting duck until it recovered.
Many Shoot 'Em Ups have player ships which shoot a spread of shots that fan out as they travel. As a result, the closer you are to an enemy, the more of your shots connect. The logical extreme is known as "shotgunning" or "point blanking", where you fly up extremely close to an enemy to shoot it point blank for maximum damage. The obvious downside is that you'll have no time to react, in a genre where you're usually a One Hit Point Wonder, so even the slightest mistake while shotgunning usually means instant death. Some games also provide additional rewards for it:
In Touhou 13: Ten Desires, bosses drop blue and gray spirit items as they take damage, and the closer you get, the more spirit items they drop.
In DoDonPachi Daifukkatsu, shotgunning enemies and bosses with your laser deals additional damage and also charges up your Hyper Counter gauge extremely quickly.
In Mushihimesama Futari Black Label, shotgunning enemies makes them drop amber gems, which are crucial to increasing your score.
In XCOM: Enemy Unknown, this is pretty much what happens whenever you have a soldier move to flank an enemy from less-than-ideal cover. If his shot connects, he'll likely kill the enemy. If his shot fails, then he's exposed himself, and possibly drawn the attention of many more hostiles. The Assault class actually specializes in these tactics, particularly when armed with a shotgun and using the Run And Gun skill (which allows for two movement actions and a shooting action), allowing them to run up to the enemy, vault over their cover, and blast them at point-blank range.
Dragon Ball Z's Tien has the Kikohou/Tri-Beam attack, one of the most high-level ki attacks in the series, capable of putting the hurt on even the most powerful of foes (It's also apparently nigh-undodgeable). Problem is that the attack is fueled by Tien's own life force, so every shot weakens him. If the foe strong enough to take more than a couple of shots and keep coming, Tien will eventually either be too weak to fight back or drop all on his own.
Hiei of Yu Yu Hakusho has an hellfire version of this, the Ensatsu Kokuryuha. The unmastered version is near-guaranteed to incinerate the enemy (as happened to the first target, a powerful FIRE USER) but will cripple the user's arm; the mastered version is even more powerful, won't harm you and if the enemy somehow sends it back to him it will power up the user, but is so tiring Hiei will fall asleep in a couple minutes.
There's an infamous cheating move in Mahjong known as "tsubame gaeshi" in which the player exchanges their entire hand with the tiles in the wall in front of them. (Video demonstration by pro player Kojima Takeo here) It's extremely obvious if anyone is even looking at your tiles while you do it, it's easy to just drop your entire hand everywhere, and generally there are about a bajillion ways it can fail and make it blatantly obvious that you were trying to cheat. But done right, you can give yourself basically any hand you want. This should go without saying, but Don't Try This at Home unless you want the crap beaten out of you by three extremely angry opponents.
The Moon Shot (or Shooting The Moon) in Hearts: Winning all thirteen tricks in a round (in a game where the usual purpose is winning as few as possible, to keep your score low). Succeed, and every other player gains 26 points. Fail, and you will gain more points the closer you came to completing the Shot, up to a maximum of 25 if you just barely fail.
Actually Shooting the Moon only requires capturing all the points, (all hearts and Queen of Spades), not all the tricks. However, if someone figures out what is going on they'll slip a heart into a trick that you can't win, so it's safest when you take all tricks.
The vast majority of combo decks follow the pattern of trying to "go off" and win in one decisive turn as soon as they collect all the pieces, which is exactly the right time to yank the carpet under their feet. This leads to waiting for the opponent to be unable to react, or preferring the lockdown style of combo in which you don't expose yourself and the opponent slowly gets hurt without being able to do anything dangerous.
Red can load their deck with cheap creatures and damage spells and hope to win in the first 5 or so turns. If the game goes too long, they don't have any 'big' spells to compete and will probably lose.
Black has lots of spells that cost life (or other non-renewable resource) to play or use, but tend to be much better due to the extra cost. Too many of those spells, and you become just as likely to kill yourself as your opponent.
Net Runner has a good number of cards that do this sort of thing, but the most "traditional" is probably Lucidrine Booster Drug. It's a card that lets the Runner make a run with a significant amount of extra money, but after the run is over, they lose any of the bits that they didn't spend, and take unpreventable brain damage.
Similar to Shooting The Moon in Hearts, Spades have Blinds, where you can bid a set amount without looking at your cards to gauge potential scoring. (Blind 7 and Blind Nil being the most common variants). Crosses with Desperation Attack, since most rule sets only allow Blinds if you have a negative score and/or are down by at least 100 points. Pulling it off gives you double points (a Blind 7 gives you 140 points). Failing loses you' double points. A Blind Nil (betting you win zero tricks) is +/-200 points, but is particularly hard to pull off, especially since there is one unbeatable card (Ace of Spades or Big Joker, depending on preferences of rules) and gaining that will instantly sink your attempt.
The Marvel Universe has the Ultimate Nullifier - a device that can Ret Gone its target from the universe itself. The catch is that the target has to be visualized perfectly within the user's mind. If the user botches it, he is the one who gets erased.
The starship Excalibur from Crusade had a superweapon that could one-shot nearly any ship in the known universe. The downside was that it drained the ship entirely of power and left it a sitting duck until it could recharge. Not a good thing if the shot misses or if the target has backup.
Episode 48 of Kaizoku Sentai Gokaiger - At the end of his final battle with personal enemy Basco, Captain Marv stomps on his foot, then skewers both their feet with Basco's own sword. Basco has a minute to comment on his sheer determination before they both fire point-blank finishing moves.
In Mercedes Lackey's The Black Gryphon, a pair of generals in Urtho's army are reknowned for these sort of maneuvers. Every time they come up in conversation, someone mentions their latest battle with the enemy, always bringing up the fact that the plan would have been a spectacular victory, except that the enemy general wasn't dropped on his head as a child, so it was fatally suicidal instead. Later it turns out that they're actually The Mole, so they have in fact been doing this on purpose.
Aerial attacks in general are booked this way. If the wrestler takes too long setting them up, the opponent can recover enough to either counter or simply dodge. Even if they're quick, one misstep can cause them to crash and burn, as many Botchamania videos show.
A non-military example: very large trades on the Chicago commodities exchanges are known as "O'Hare trades" (after the airport.) The reason being: if it goes well, you can take a nice long tropical vacation to celebrate, while if it goes badly you'd better flee the country.
To elaborate, commodities futures are highly leveraged- a small down payment for a contract to buy a large amount of the underlying on the expiration date. If it goes in your favor, you can sell your contract (or the underlying) for a substantial profit. However, if it goes against you, you are stuck putting up cash you may not actually have in order to cover your losses.
There are many examples in MMA and fighting in general. For example, a haymaker thrown with all your might will most likely knock your opponent out if it lands - but your movements will tell your opponent what you're about to do, and you leave yourself open to a number of counters. Likewise, a flying submission can end a fight quickly, unexpectedly, and stylishly, but if it fails, you'll find yourself on your back with your opponent on top of you, likely raining down punches.
High kicks. Easily punished, but with the power of the kick and hitting the head it's not pretty for the guy it connects against.
The German Kaiserschlacht offensive on the Western Front in 1918. The Russian Revolution closed down the Eastern Front, and the Germans concentrated the last of their elite troops for one more shot at beating the British and French before the US Army entered the fray. The British knew what was coming, and had it lampshaded even before it happened: "If Germany attacks and fails, she will be ruined." Germany attacked, failed, and was ruined.
Predators who practice Cursorial Hunting. Chasing prey into rough terrain or over too long a distance will result in prey too weak to fight or escape (if it doesn't simply drop of exhaustion) or a hunter too weak to find alternate prey if it escapes.
In general, any strategy that focuses on offense over defense falls under this, especially in team sports. Specific examples include:
The blitz in gridiron football, which is when a large number of defensive players rush the quarterback in order to force a sack or worse. Done badly, it leaves receivers wide open for big offensive plays.
Two particularly high-risk variations:
Corner Blitz: Sending a the cornerback in after the quarterback, usually done to the QB's blind side. If spotted, at best (for the defense) the receiver is going to have a mismatch downfield (covered by a linebacker or safety not fast enough to keep him from getting the ball with room to spare). At worst, he's completely uncovered with room to run.
The All-Out or "Jailbreak" Blitz: The Zerg Rush of football. Basically sending every defender after the QB. Rarely seen in modern football above the high school level because of the insane risk (basically you nail the QB for a huge loss or they score an easy touchdown).
Replacing the goaltender with a regular player in ice hockey gives the team an advantage while leaving their net wide open. Another strategy, which is somewhat common on the powerplay, has one or both defensemen replaced with forwards so they can use the position on the ice for clear shots from the point, the downside being that they're less competent on defense which increases the risk of a shorthanded opportunity for the other team.
On the other hand, pulling the goalie on a delayed penalty is a nearly zero-risk proposition, because the play will be blown dead as soon as the other team touches the puck. The only way it can backfire is if a member of your team accidentally sends the puck into your own unguarded net. Otherwise, pulling the goalie is almost exclusively a Desperation Attack to tie the game late in the third period. Since there's no downside to losing by two goals instead of one, you have nothing to lose by pulling the goalie to try to tie the game.
Made harder in association football due to the off-side rule being based on where the team's defensive players are, however, like ice hockey, bringing the goalkeeper forward gives the team a numerical advantage in attacking while leaving the net open.
A riposte (or kaeshi if you must) can be like this. It's really cool if you pull it off, but if you mess up prepare to look stupid.
A Fleche in French fencing is like this. The attacker runs at his opponent, leaps and attacks, then runs past as he lands. If executed properly, it's almost impossible to parry. If done improperly, the attacker is wide open for a counterattack. If done really badly, one or both of you will end up in a heap on the floor...