Torgue is adamant about destroying laser guns in Borderlands: The Pre-Sequel! because they don't explode. At one point, he sends fifty barrels of high explosives crashing down on a laser rifle, via spaceship, so it explodes the bridge it is on and makes it fall into a river of lava. Keep in mind: this was to destroy one laser rifle.
This occurs almost constantly in Orcs Must Die and its sequel. You create hallways of death through which the hapless orcs have to run. While doing so, they are subjected to your traps which do things like crush, burn, slice, dice, pulverize, catapult, explode, crush (from the side), shred, impale, and dissolve (among other things). Though there are some larger enemies (especially in the sequel) which can survive multiple traps, the standard orcs do not and are usually reduced to Ludicrous Gibs with one trap. Because they come at you in massive waves, there are orc bits flying around almost constantly.
American Conquest has this relation with even the most primitive firearms - a matchlock arquebus deals about three times more damage than even the strongest units may take. And then you have muskets and fusils - the latter can be even upgraded to inflict One Hit Polykills in case you have another target right behind the first one. The only thing that prevents firearms from being outright Game Breaker is their inherited inaccuracy and relatively slow reload - at least for earlier types.
In Just Cause 2... Let's just put it this way. You have options. Sure, you can shoot a guy in the head with a revolver, but where's the fun in that? Why not attach his military jeep to a helicopter and drop him from a mile high, Blues Brothers style? Or throw him out of the jet plane he was piloting, attach him to it using a grappling hook, and then crash the entire thing into a military base for bonus points?
Some of the mods available for this game take this up to eleven. Take for example the Jet Propulsion Gun, a DLC weapon which knocks people a fair distance and flips cars over. One of the mods increases its power massively, so instead of knocking people off their feet, it sends them into a low-earth orbit. See also the Rocket Launcher mod which increases it's rate of fire, and makes the explosions cause everything within a mile of the explosion to die instantly (including you).
Most of Dr. Eggman's mechs can be considered this. Yet they all fail.
Egg Saucer in Sonic Advance 2 certainly features an overkill attack: Simply gives you an open-handed slap. Not only it knocks your rings off but also kills you instantly. Even if it misses, don't even dare to touch that hand.
Half-Life 2 actually lampshades this in one of Dr. Breen's speeches.
"You, on the other hand, will be destroyed in every way it is possible to be destroyed, and even in some which are essentially impossible!"
In Rune Factory 3 you can continue to hit a dead enemy if they are knocked into the air. You can do this for hours if you want. Additionally, while in wooly form you can grab a dead enemy to perform a fatality on them.
One of the oldest examples is Scorched Earth. Nukes, Plasma Blasts, Hot Napalm, the Funky Bomb, and the aptly-named Death's Head. Quite capable of destroying large sections of the map, especially with the explosive sizes on maximum in the game's configuration. The Death's Head is so devastating that if fired wrong it can kill everyone on the screen. Including the player who thought firing it was a good idea.
Before them all came Turok; a series of games that lived and breathed this trope. The original game had the quad-rocket launcher, which fired off fourhigh explosive missiles at once - and it was one of the weaker weapons in your inventory. The fusion cannon was basically a tactical nuke-cross-BFG that decimated everything within a square-kilometre in a bright red flash. The... You know what? Just watch this.
Its sequel, Turok 2: Seeds of Evil, actually managed to top it. Because hunting dinosaurs requires heavy firepower. Aside from the usual final-game devastators, a particular mention goes to the Cerebral Bore, which fires shots that embed themselves in your enemy's skull. Then they start drilling. Then they explode. One-shot-kill everything.
Moreover, Turok really doesn't do any hunting himself (though some dinosaurs do attack, and some are actually armed later on), but rather, he fights many humans clearly designated as hunters/poachers. That's right. Turok carries enough firepower to hunt people who have enough firepower to hunt dinosaurs.
Command & Conquer thrives on this trope. Whether it's constructing an army half the size of the map, sending said army against one particular enemy or structure, to the units such as double barreled tanks (Mammoth and Overlord), nuclear cannons and trucks, and an orbital laser. Generals ramps things up with faction generals that specialize in a particular aspect of their army, and that includes a nuclear general, a laser general, and an explosives general. Then there's a secret general in the Challenge mode who has access to all superweapons; she introduces herself by firing every superweapon simultaneously at a column of tanks.
Speaking of Command and Conquer, just wipe out the majority of your enemy and decide to leave his Construction Yard barely intact with a little HP left? The perfect solution is to move your troops away, then launch your superweapon at the opponent's Construction Yard. Nothing quite so satisfying like kicking someone to the curb like that.
The canonical ending for Tiberian Dawn requires the GDI commander to do that to the Nod Temple — unlikely in the videos, in the actual gameplay a single Ion Cannon blast can't destroy a Temple... and the Brotherhood repairs the Temple quickly enough that by the time the Ion Cannon has reloaded, the Temple is fully repaired.
The "Command & Conquer: Retarded" Game Mod makes everything overpowered. The nukes, for instance, now have three times the power and area of effect.
The Shogun Executioner in Command & Conquer: Red Alert 3 - a giant tripod with three bodies, each of which is armed with a Laser Blade. It's also healed by electricity, and many of your enemies in this level are armed with Tesla coils. Oh, and it's tall enough to knock helicopters out of the sky just by walking into them. You can lose it, though, if not careful.
Gears of War 2: Single enemy infantry who has been incapacitated? ORBITAL LASER. Overall there is a ridiculous number of methods to reduce enemies to chunky salsa, and even more to execute downed enemies.
In fighting games, it's a generally common practice to finish a near KO'd opponent with a Super move or a rapid combination attack, just to finish off the match with flair, at least casually.
In addition, Akuma players especially like to finish off opponents with his Shun Goku Satsu move (Translates to "Instant Hell Murder", also known as The Raging Demon) which is possibly one of the most satisfying, and most predictable, moves in fighting game history. Pulling this off results in a giant burning 'Ten' symbol covering the screen in addition to the standard 'Flash', mirroring the one on Akuma's back. Taken to its logical conclusion by Tokido.
In certain games, you also have the Brutalities, which are pretty much Fatalities on steroids. You have to do an 11-button combo to get it. The reward? Your opponent explodes in a shower of gore and bones.
The 'fatality' move of Smoke: when the opponent is dazed and reeling from side to side, the robot's chest opens and a bunch of small bombs tumble out. Cut to a shot of the planet Earth from orbit — which then goes Kaboom, captioned with the rather helpful assessment that "Smoke Wins".
In Mortal Kombat 9, the first of Quan Chi's fatalities involves ripping off your opponent's right leg and then hitting him with it so that he falls to the ground. Once in the ground, Quan Chi hits him in the head twice with his own leg and then it explodes in little fragments. And after that he keeps beating him to a pulp while the fatality assessment shows up and until you exit the match. Who needs necromancy, eh Quan Chi?
Hell even some non-Fatality victory poses in Mortal Kombat 9 could be considered overkill. After finishing off an opponent, Stryker will casually toss a grenade over his shoulder, giving us an offscreen explosion complete with a rain of blood.
The Fighting Game based on JoJo's Bizarre Adventure rewarded a Super KO with a Reaction Shot of your opponent (drawn in the style of the manga) gasping in pain, Blood from the Mouth, scrolling into place in the background before fading to white and cutting back to your character's Victory Pose. Really satisfying. Furthermore, depending on how the opponent was finished off, the portraits would show it. If you used Dio's blood suck super or Hol Horse's J.Geil super for example, the portrait would be covered in blood and slowly turn green. If killed by any of Black Polnareff or Chaka or Kan's supers, the portrait would split in half/quarters, and if beaten by Hol Horse's super or one of Polnareff's supers, the portrait would be covered in holes.
Killer Instinct and its sequel introduces, as well as the standard fatalities and humiliations; Ultimate combos, which automatically end with a fatality, and Ultra combos, which can escalate the hit counter somewhere into the upper eighties. Of course, the only time you can pull off either of these is when your opponent has barely enough health to survive a standard combination...
Of note is one of Fulgore's finishers. The screen darkens, he pulls off his (normal-sized) head... and out pops a machine-gun turret worthy of sitting atop a literal tank, let alone a robot. I wonder how he fit it in the regular head?
Speaking of supers, Maxima's HSDM in The King of Fighters 2002: Unlimited Match defines this, brutalizing the opponent with a barrage of missiles, before making totally sure by blasting them to Kingdom Come with a laser cannon from his chest. Not that his old HSDM (demoted to SDM) was less brutal, since it had him throwing the enemy to the floor with a painful looking body slam, before Bunker Bustering into their spine, for repeated hits and huge damage. By then it should be a wonder if the opponent is still standing after having their spine essentially ground to dust.
In the Knights of the Old Republic RPG game, Darth Malak orders the orbital bombardment of Taris, killing 6 billion people in a failed attempt to kill one woman! All because the search for her was taking "too long."
In an odd twist of fate, he was right that it was taking too long; unfortunately, he realised this too late to actually stop her.
In the Xbox remake of Ninja Gaiden, it's easy as pie to keep comboing a dead and decapitated foe with the Vigoorian Flail until the poor sucker finally disintegrates into a cloud of red dust. It's harder but more satisfying to do it with other weapons.
In The Outfoxies, this is how the final boss is defeated: after destroying their helicopter, Mr. Acme falls onto the roof of his home. Mrs. Acme, his rotund wife, falls on top of him, driving his health bar down to a small sliver. That sliver is shaved off when his helicopter crashes on both of them.
In Samurai Shodown, defeating the foe with the right move (usually the strongest slash a character has, but there are some exceptions) will cause them to be bisected and golden charms to fall out, leaving only their weapon in the ground.
Samurai Shodown gets worse than that. In IV, at least, if you defeat your opponent by a lot and finish with a strong attack, you can perform a "final" attack that will cut them into pieces with blood graphically spurting out.
It gets even worse: In the original version of Samurai Shodown V Special, you could, under certain conditions, perform a (very violent and graphic) move called the "Zetsumei Ougi" which would actually kill your opponent (thus ending the match); the relevant part is that, for a number of characters, it went beyond just cutting the opponent up: some of them would literally destroy the opponent's body leaving nothing behind, save perhaps a head, a skull, or a rain of blood. See here.
In the Battlefield series, using a tank's main gun or anti-tank weaponry on a soldier qualifies, in that the game will not let one of their teammates revive them from that.
Or on sea maps, where you can actually use a cruiser's 12in main guns to shoot infantry.
What feels better? Instakilling someone from behind with a knife, or dropping a shit-ton of C4 around them and detonating?
Star Wars Battlefront has a few examples, especially using an AT-AT to step on people and using AT weapons against infantry. The command classes in Battlefront 2 are good examples; the Imperial Officer and the MagnaGuard have grenade launchers, the MagnaGuard also has a rapid-fire rocket pistol, the Clone Commander has a man-portable heavy machine gun, and the Bothan Spy can turn invisible and has an incinerator.
The Special classes also count; the Destroyer Droid has machine guns and an energy shield. The Wookie has twice the health of normal infantry and has the bowcaster, which can shoot a shotgun-like burst that can easily kill at close range but can also charge up to fire a powerful shot that will take out nearly any enemy trooper. It also has a two-level zoom scope for sniping with the charged up shot, as well as a grenade launcher for a secondary weapon. The Dark Trooper has a lightning gun that can kill four soldiers at once. The Jet Trooper has an EMP rifle that can one-hit-kill anything but main battle tanks and Jedi, and the last two have jet packs.
The award upgraded rocket launcher allows a Vanguard to stand back and snipe infantry with short-range anti-tank cruise missiles.
The fan-made maps "Capital Ship Down" 1 and 2 are very good examples of why the second game left out the infantry maps with starfighters on them. A Y-wing can take down an AT-AT in two hits if they are carefully placed, and the bombs have an insane blast radius when used against infantry.
The Disgaea series in general is filled with this. It's not uncommon to be hitting enemies for billions of points of damage at higher levels, when the most HP you'll generally ever see anything with is in the low 10 millions. The third game is particularly guilty, due to the damage formula making the effect of the defense stat completely negligible against higher amounts of damage.
Then there's the attacks used to cause said damage, which include things like punching the moon into the target and explosions big enough to destroy the world and neighboring celestial bodies.
Eternal Champions had overkill moves that were specific to each stage: if you can defeat your opponent and get their body to fall on just the right spot, they'll be chopped up by a fan, or fall into a vat of acid, or get impaled on the Washington monument, to name a few. The Sega CD remake also added a second form of Overkill, and featured more standard Vendettas, which were always overly bloody. One of the simplest, but most brutal one was where the character would pull out a knife, and stab his opponent until the screen faded out.
Also in the Sega CD version were the "Cinekills", in which the defeated fighter is teleported to the Dark Champion's realm, where the Dark Champion personally executes the defeated fighter, in cutscene form. However, it is difficult to pull off a Cinekill.
At the end of a game in Team Fortress 2, the losing team are rendered unable to use their weapons, with their speed decreased by 10%, and the winning team have their critical hit ratio increased to maximum. Also, the losing team's spawn area (normally the only safe area for them on the map) becomes accessible by the opposing team. If the server settings are particularly mean, the losing team can still respawn in that phase, only to be killed again by the winners.
The Spy's Backstab is meant to be a One-Hit Kill. To make sure it always is a one hit kill, Valve gave the Backstab the ability to always deal damage equaling twice the target's maximum health. And since it's a guaranteed Critical Hit, which triples the already high damage, you're doing damage equal to 6 times the enemy's max health. Getting a backstab on a Heavy does an absolutely ridiculous 1800 damage on an enemy that has 300 health (sometimes 450 health).
And if you manage to back-stab someone while they are in mid-air, their body will go flying at extreme speeds until it hits a wall or tumbles to the ground.
The Half-Zatoichi can deal 600 damage if the player hits an enemy wielding the same weapon. This mean a Demoman can one-shot a Soldier in the front with a crit sword attack for the same damage as a full health Heavy Backstab.
Most weapons feature a "taunt kill". It causes 500 damage caused by the following: a ultra-strong bat swing, a kamikaze grenade attack, a Hadouken, a point blank flare to the face, a ring of fire, a sword swing that is full of honor, a finger gun, getting hit in the head by a guitar, a robotic hand spin inside your guts, a stab from a saw, a stab from an arrow, and a fencing with a butterfly knife.
Final Fantasy X actually rewarded players for doing exactly what the word "overkill" implies. Finishing off enemies with a hugely damaging attack would increase the XP/gold gain and raise the odds of better item drops. Anima is the ultimate overkill machine, capable of inflicting 3199968 damage in two turns.
A similar system is used in Bookworm Adventures (only it grants gems that bestow status effects and damage bonuses).
Cactuars can use 10,000 needles to kill someone instantly unless their HP is above 9999 via Break HP Limit. Bonus Boss (one of many in the Monster Arena) Cactuar King uses 99,999 Needles, which does that amount of damage. Even though you can obtain the Break HP Limit to break your HP cap to go beyond 10K worth of HP, you will never survive this attack (unless you have Auto-Life), even if you use a Game Shark to make your HP go that high.
Also an element in Final Fantasy IV - since magic spells are cast faster if used more often, it's quite reasonable to return to early parts of the game to cast Holy and Meteor on goblins to take advantage of this. Of course, nobody ever tells you about this.
Final Fantasy VIII's summon Eden. Nothing says 'overkill' like shooting your enemy with a beam that blows up the next galaxy.
While it's referred to as "Overwhelm", wiping out the entire enemy party in a single turn, without giving them the chance to strike (or negating all their attacks) and hitting their weak point nets you more of a Macca Bonus in Devil Survivor.
Start a New Game+. Bring out your endgame demons and use their most powerful attacks, and enjoy the five-digit damage. On low-level demons.
Final Fantasy XII's Quickenings. One can easily enough get the first Quickening for everyone in the party within the first hour or so of gameplay.
Note that a long enough chain also does a massive AOE on top of the damage the Quickenings themselves do. You can one-shot most of the bosses AND their minions without ever getting touched.
Not simply a long chain, but a mixed combinations of different leveled Quickening. For example, Black Hole, the strongest AOE attack, requires 4 Level 1, 2 and 3 Quickenings each.
In Drakengard, the weapon levelling system encouraged the player to continue slashing enemies long after their health ran out. Consecutive hits would increase the experience one obtained from defeating enemies.
Many networked FPS games (like Unreal Tournament) allow you to get Ludicrous Gibs from shooting fallen foes enough or blasting them. This behavior is encouraged in some by the ability of enemy medics to revive them.
"Jailbreak" for Unreal Tournament: When the enemy team is captured, the execution is, most of the times, real Overkill. In one map in space, each team's jail had 5 vertical tubes, and when the entire team was captured, the 5 tubes opened and 5 Redeemer warheads fell on the room, exploding simultaneously and turning the unfortunates into molecules and some flesh bits. The other one had big fans in each jail, ready to slice the losers to death.
Also, The Nail Weapons II X weapon pack for UT99, and the Redeemer, which tends not to even leave chunks, let alone a corpse.
The Unreal Tournament games are famous for several mods that turn this trope to eleven. Unreal4Ever, for instance, is nothing but ridiculously overpowered weapons, from one that makes your enemy explode in a giant fireball that kills anyone else nearby to one that makes blasts several times as large as the Redeemer's, to one that makes black holes that can suck the entirety of a small level's worth of foes in them and then explode. Game balance? What game balance?
In Final Fantasy Tactics, Take Your Time + Level Grinding = massive amounts of overkill for story battles, since they always have a default level. The downside to being able to drop a Meteor on, say, Algus is that quite a few of the random encounters afterward (why hello, Mr. Red Chocobo!) have the potential to unleash similar amounts of overkill on your party.
Metroid: Fusion: In order to truly ensure the extinction of the X parasites, Samus can't rely on the Biologic Space Labs station's self-destruct systems alone; the only way to make sure they're absolutely wiped out is to deorbit the station with the self-destruct on a timer, and thus Colony Drop the station far enough into SR388's atmosphere to set up a planet-nuking chain reaction. Partially justified in that a station dedicated to biological (biological weapons?) research would have to guarantee that the station's remains were sterilized as well as destroyed, hence the absurdly powerful SD system.
A more personal example occurs in Metroid Prime 3: Corruption. During the fight on Norion, Samus free-falls down a sixteen-kilometer-deep generator shaft in pursuit of Space Dragon and series Recurring Boss Ridley. After administering a long-distance thrashing with beam and missile weapons, she lands on his head, pries his jaws open and jams her cannon arm down his throat before firing several more rounds "down the hatch."
Fellow Big BadMother Brain ends up on the wrong end of another such smackdown in Super Metroid, when she murders the infant metroid from Metroid II and earns herself a Hyper Beam-fueled Roaring Rampage of Revenge from the creature's human adoptive "mother." The final shot decapitates Mother Brain, exploding her cybernetic combat body; her severed head turns to gray powder as it hits the floor.
In a straighter example of this trope, killing any regular mook with your most potent weapons (such as the missile combos in the Prime series - which include a flamethrower, an ice bomb, and a black hole, among others).
Enemies and characters killed in Enchanted Arms stick around for three turns, during which time they can be resurrected. If, however, they are killed by inflicting more than double their total health in one attack, they disappear instantly and can't be resurrected until the end of the combat.
In the shooter Call of Juarez, Reverend Ray can initiate a Bullet Time mode at will, causing to draw your six-shooters and have your crosshairs go towards the center from left and right... allowing you practically kill an enemy, use the Bullet Time, and then unload 12 bullets in them.
The expansion pack for Age of Mythology allows the player to create a Titan (i.e. a god). They cost almost as much as a Wonder and take almost as long to construct (i.e. a shit-load of time and money), but watching an unstoppable hundred-metre-plus-tall engine of destruction effortlessly carve through enemy armies and bases is extremely satisfying.
Unless you actually target the enemy base, the titan will just fall to attrition, as it will constantly attack units if they attack them, meaning if you continuously make and send just one unit at the titan at a time, it will eventually die with you little closer to defeat. It'll still cost a lot of resources though...
Super Robot Wars games can sometimes encourage this by giving "Dynamic Kills" to certain attacks; if they deal enough damage to kill, the animation will change to integrate the enemy's destruction, for instance having a super-powered punch drill straight through the target, or an energy blast's explosion keep burning until there's nothing left.
One of the first instances of this was Daitarn 3's Sun Attack. If the attack will just harm but not destroy, the attack is simply an big blast of energy. If it will, it's actually the blast carving a hole out of the enemy, and Daitarn drop-kicking the "plug" out. His team attack with Zambot 3 elevates it to the point both machines do the drop kick.
All child's play compared to the destructive power of the Valzacard from Super Robot Wars W. Its weakest attack is a huge and extraordinarily powerful blast of energy. Its trademark sword attack has a dynamic kill that breaks through the fabric of space, blasts the enemy into another dimension, and breaks through the other side. Its strongest attack, EX Nova Shoot Over, I couldn't even begin to describe. It starts out as turning the Armstra into a giant bow and arrow, then it just goes crazy from there. Really, you'd have to see it to believe it.
Then there's Regret Buster, pretty much Valzacard on steroids minus 4 pilots.
Darkbrain's ultimate attack is just ridiculous. One part of it involves slamming in the enemy into a few planets, the second part is a laser-punch through nine planets and assorted meteors, and the last part involves dropping them through a hole in the universe.
You're actually encouraged to do this during boss battles, as unleashing several ridiculously flashy and powerful attacks, all at once, is the only way to do any decent damage; particularly if the boss in question has the ability to heal each turn.
The Inspector (Anime of Original Generation 2) pokes fun at this somewhat by having numerous characters mutter "Just one more hit" during fights. And the Finale further Lampshades this when the Einst make doppelgangers of their machines that also have the ability to regenerate. They deal with the problem by breaking into smaller teams, then ganging up on each copy with their strongest weapons.
Dwarf Fortress features several levels of overkill, especially in Fortress Mode, ranging from champion macedwarves playing Goblin Golf to weapon traps each equipped with ten steel large serrated discs (each of which hits three times per activation) to flooding the world with lava to kill one elephant. And if you can think of a better one, go ahead and try it out, chances are it's perfectly possible.
The combat system of The Force Unleashed is practically built around this entire concept, although special mention must go to the ability to hold a stormtrooper in the firing path of the DEATH STAR.
The Star WarsRTS game Empire at War allows you to build the Death Star and use it in space combat. Destroying the planet means that there is no ground conflict, allowing you to control the planet just by winning the space battle.
The Forces of Corruption expansion takes it one step further by allowing you to build the Death Star II, which not only can destroy the planet, but also fire on enemy capital ships and space stations during battle! It also allows the empire to get the Executor, a Super Star Destroyer bigger than the screen at normal zoom, that carries more weapons than a space station and can deploy eighteen fighter squadrons; it can often take any but the biggest rebel or Consortium fleets on its own. And to add insult to total destruction, it only costs 3 pop cap, the same as a frigate. In other words, its a Gamebreaker extraordinaire.
Recurring Optional Boss Iseria Queen from Tri-Ace's games is almost inevitably based around this - of course, since she's a boss, YOU are at the receiving end. Perhaps the best example is her appearance in Valkyrie Profile... her standard attack is a 25-hit combo, each strike dealing damage above your characters' Max Possible HP. Don't ask about her Special Attacks.
Not that Valkyrie Profile expects the player himself to raise this trope to a philosophy for the duration of gameplay. "Soul Crush" indeed.
And if you don't regularly indulge in massive overkill, Hel herself gets enraged and sends in horribly powerful monsters as punishment. Attacking efficiently is a very bad idea, so much did the designers love overkill.
Pretty much the logic behind the Bloody Mess perk in the Fallout series (only in Fallout 3 and New Vegas does it actually provide any benefits). Normally, when an enemy dies, they fall down, possibly losing the last body part you shot at. With Bloody Mess, other body parts will fall off for absolutely no reason. There's nothing quite like detonating a super mutant by punching it.
Fallout incorporates many weapons designed for overkill fanatics. The original Fallout sported a rocket launcher, a minigun (and a laser variant), and a turbo plasma rifle (which is the most powerful weapon in the game overall); Fallout 2 had new fun toys such as the H&K G11E (the best submachine gun for Small Guns users), the Vindicator minigun (an even stronger minigun), a pulse rifle (which is even stronger than the turbo plasma rifle and causes electric death), and a secret Holy Hand Grenade (deals area damage of 300-500, enough to kill many enemies 3 times over); Fallout 3 has the infamous Experimental MIRV, an improved Fat Man that fires 8 nukes simultaneously in a wide spread.
Even without the Bloody Mess perk it was possible in Fallout 1 and 2 to finish off someone with a burst from even a modest submachine gun from point-blank range, which would literally rip his upper torso apart.
Gauss weapons are great for dealing with armored targets like robots. The Gauss rifle is the logical step up, and both the pistol and rifle are from Fallout 2. But Fallout Tactics takes things towards the logical extreme with the gauss minigun, which has fairly long range for a minigun, tears through huge groups of (high-powered) enemies like they were nothing, and is more powerful than the Browning M2. It also eats ammo like popcorn so you'll be saving it for the endgame.
If you fight Ulysses in the Fallout: New Vegas "Lonesome Road" DLC, he will pull this on you, being Dangerously Genre Savvy enough to know that the Courier won't go down in a one-on-one fight. He brings regenerating Eyebots and convinces the Marked Men into the fray to make sure you don't get out and have revenge.
New Vegas's DLC, Gun Runners' Arsenal, adds a challenge in which the Courier must kill an unmutated animal (some of the weakest enemies in the game) with either a mini nuke or a mine built using one. It's appropriately called "Overkill".
Likewise, you can invoke this by reverse pickpocketing a Fatmine onto an NPC. You don't have enough time to outrun the blast radius, so if you survive the explosion, good luck with finding anything left of the corpse.
In Supreme Commander, there's nothing like inundating your opponent's base with Tier 3 stationary cannons situated on the other side of the map, watching as their shields collapse and their buildings explode...unless it's queuing up a bunch of nuclear warheads that overwhelm their anti-missile defenses and reduce their base to a lifeless smoking crater.
In some cases this isn't really There Is No Kill Like Overkill so much as you must have twice as many nukes simultaneously striking the target as the enemy has strategic missile defense silos plus one in order to hit, because each defense can shoot down two incoming missiles before impact... though that doesn't stop you from building many more silos "just to be sure".
And the true overkill comes with the aptly named game-ender experimentals. They cost about as much as 20 'regular' experimentals. Even a single experimental is a threat to most bases, and if your opponent has the same amount of resources as you have but used them to build the cheaper experimentals, he'll have overrun your base long before your game-ender is done. But oh, what fun if you can get one of them deployed. To wit: An even more powerful artillery cannon than the tier 3, which can hit anywhere on the map with perfect accuracy, a mobile artillery installation that fires one round across the map per second, an artillery cannon that shoots one shot per 3 seconds which splits up into 6 projectiles, who each split up in 6 more projectiles, and a nuclear missile launcher that builds nukes very fast, for free, which take 2 countermeasure missiles to kill, and do 10 times more damage than the strongest unit can take in a huge radius. Oh, and there is one experimental building that produces nigh-unlimited resources.
You don't even need this. You can just set up a manufacturing plant that just makes tons and tons of gunships. Add in the above stationary guns, and you will obliterate everything.
Predecessor Total Annihilation has many of the same things, including across-the-map artillery and nuclear missiles. It also allowed for massive rushes that were never repeated until the sequel came out many years later.
Its fantasy cousin Total Annihilation: Kingdoms allowed the player to build gods. They took a ridiculous amount of time to build and the build process was a massive resource sink, but once built they could not be stopped. Their health was so high as to make them virtually invulnerable, and just one shot could destroy half an enemy base.
World of Warcraft has the Warrior class, whose Execute ability is typically the strongest single attack, and burns all of their Rage to make it more powerful - but can only be used on opponents under 20% HP. It's, well...
Sadly, after a patch, Warriors can only burn 30 rage at a time. Good news is you can take talents to get a chance to use it outside the 20% HP mark.
The Paladins have their own version, Hammer of Wrath. And fire-spec Mages passively deal more damage, all to targets under a fifth already.
Drain Soul: Normally, it does some low damage and restores soul shards if it's up when a target dies. Use it when the target is under 25%, and whatever you're aiming at is going to drop fast.
Soul Fire: Nothing says "die!" like a huge ball of fire that crits for 10k.
Shadow Bolt: Except maybe the screaming skull made of darkness that crits for 20k.
However, despite the overkillness of those abilities - against bosses, who will still have a ton of health despite being at 20%... these can really win it for you in Player Versus Environment fights.
Even Priests get one of these, with a twist. Shadow Word: Death is a finishing move that causes a huge amount of damage... but if you don't kill the enemy with it, you take the damage as well. Since Priests are so squishy, the spell often ends up doing what it says on the tin either way. (Mostly, this is due to its instant cast and faster cooldown.)
C'thun Green Beams. Imagine the standard chain lighting spell, except it doubles in damage each time it hits. If you screw up on starting the fight, the last person will be hit for several tens of millions, at the time the boss was released, that's many times your maximum health.
Mimiron will launch some rockets from time to time. They are not hard to dodge, and will do no damage outside a rather small area. Fail to dodge them, however, and you get hit for 5 MILLION damage. If, at that stage of the game, you have 1% of that, you can consider yourself a damn tough Tank.
Monks have an ability called Touch of Death which is only usable on enemies with equal or less health than them and deals damage equal to the Monk's maximum health. A level 90 Monk Tank can have over a million hit points, a level one enemy has 55.
Final Fantasy VII has this in terms of game mechanics, the graphics of attacks, and plot.
Knights of the Round is the strongest summoning in the game, using multiple attacks in one animation to circumvent the 9999 damage cap. Its animation takes about 1:15 minutes. W-Summon means you can use a Summoning twice in one round. Mimic lets a character... well, mimic the action of another. Putting this together, we get 6 KotR summonings in one round by letting one character do the W-Summon with the other two mimicking him. Of course, this has a drawback — you can easily get up, make yourself a sandwich and eat it before continuing with the game without missing anything apart from animations of monsters being hacked to very fine bits.
Additionally, we have the Infinite Omnislash, where equipping Cloud with 8 pairs of linked Counter (which counter-attacks with the linked materia when hit) and Mimic (which repeats the last action) Materia allows you to unleash a 16-hit Omnislash on an enemy, which will then be repeated 8 times every time he is hit. This is a great way of taking down some of the toughest bosses in the game solo.
Cid's Highwind and Barret's Ungermax can do this if properly set up (both do 18 hits). A few Hero Drinks and either one can basically decimate Emerald Weapon in the same setup.
Overkilling in both effect and length of cutscene is Sephiroth's Supernova. He summons a fiery ball of destruction which destroys Pluto, Saturn, and Jupiter before slamming into the Sun, causing it to erupt and swallow Mercury and Venus and tear apart the Earth! The animation takes two minutes, he can summon it multiple times in the same fight (destroying the Solar System each time), and you cannot skip the animation. Due to the games' mechanics, it won't actually kill the heroes.
In Dissidia, Super Nova returns, although not as long (or explosive). However, one of his HP damaging attacks does include dropping a meteor upon his opponent. The blast is so bright that your screen will flash white, and it leaves lightning, flames, and black clouds in its wake.
ShinRa's plan for destroying Avalanche is most definitely this. They destroy the pillars holding up the Sector 7 plate, killing not only thousands of people living in the slums below but also the thousands living on top the plate, all to kill six people. And they only manage to kill three of their targets.
Summons in general have a tendency to look more and more exaggerated as they get more powerful. The three "Bahamut" summons each have a bigger explosion-via-energy-beam-spat-by-a-dragon, with the last one having the dragon shoot the beam from outer space and causing a big enough explosion to be seen from that distance.
Kingdom of Loathing has a mechanic whereby dealing large amounts of extra damage to enemies in a certain area will cause parts of their bodies to fly off, which you then acquire in place of the enemy's normal item drops.
This is actually a very useful strategy for speedruns in that area (and pretty much mandatory if you want the best item to drop at the end). It also has elements (pun not intended...) of Elemental Rock-Paper-Scissors, since the type of damage dealt sets the bodypart dropped- for example, Spooky damage "Scared the [enemy] so much he left his skull behind!"
Excessive Sleaze damage causes the hobo to leave his crotch behind.
Ike's Final Smash in Super Smash Bros.. Brawl involves striking the enemy once, then catapulting them into the sky, where they are then slashed repeatedly with his sword before being hurtled back down to earth (and usually, back off into the sky).
Almost all Final Smashes are like this. Sonic and Pikachu start flying around dealing huge damage to whatever touches them. The Starfox fighters break through with their Landmasters. Mario shoots a ludicrously large fireball across the screen. Link does a combo of about two dozen hits before sending the enemy flying away. And that's just the tip of the iceberg. Some of these can, with the right timing, kill an enemy, and then kill them again as soon as they have respawned and their Mercy Invincibility has expired.
Brutal Legend has a move which summons a giant, flaming zepplin that crashes into your enemies like a Hindenburg from Hell.
Modern combat RTS Act of War: Direct Action has each faction equipped with a superweapon and counter-superweapon. International terrorist ring The Consortium's superweapon houses 3 shots per structure (and you can build multiple structures), making it alarmingly easy to simply inundate a base with superweapon attacks faster than the enemy can counter them. In addition, the Consortium superweapon is a satellite nudged out of orbit onto the target...but first, coated in e. bola. Needless to say, the strategy of "launching more satellites than you have Patriot missiles" tends to warrant some overcommitment of resources, just to be on the safe side.
Pokémon: While not entirely the fault of the game itself, moreso that of the player, but there's nothing quite as satisfying as roasting a Lv. 2 Caterpie with a Lv. 100 Charizard with max Special Attack, using the strongest Fire-type attack in the game... and scoring a critical hit. It's even worse when you use Psychic with a Lv. 100, max-Special-Attack Mewtwo against a Lv. 2 Weedle... and still get a critical hit. At that point, it's not out of the question for a player to experience a momentary A God Am I feeling.
Kill It with Fire taken to the extreme: Given the structure of its evolution line, it's possible to produce a Level 1 Scizor (4x damage from Fire) specifically for link battles. You also get the same effect from breeding out a Level 1 Paras - which also has much lower defensive stats and has an ability which can increase its vulnerability to fire. Toasty!
Take a Lv. 100 Heatran (highest Special Attack of all Fire-types bar Reshiram and Mega Evolutions), give it Choice Specs (boosts Special moves), boost its natural Special Attack all the way up, change the weather to sunny, activate Heatran's Flash Fire, and attack the above Paras with Overheat, the strongest Fire-type attack Heatran can learn. Put that through a damage calculator, and the damage reaches the millions - 6255207 damage. That would essentially erase that Paras from existence.
For added fun, replace Paras with Scizor and have a Trevenant use Forest's Curse to add the Grass type to it beforehand, giving it a 6x weakness to fire!
It gets better. As of Pokémon Ranger: Guardian Signs, Heatran can use the more powerful Eruption. Meaning that at full health under sun, with +6 Sp Atk and boosts from Flash Fire, Helping Hand, a Cherrim's Flower Gift and a critical hit, with the target Paras at -6 Sp Def, Heatran can deal over 10 million points of damage.
The maximum possible amount of damage dealt in one turn by single pokemon is believed to be this: A Shuckle with 614 attack stat from Power Split, two Helping Hands, two Flower Gifts, skill-swapped Huge Power ability, at +6 Atk, with x2 boost from Metronome item, using Me First boosted Rollout after a Defence Curl, with Same-Type-Attack-Bonus, on a 4x Super-Effective Critical-Hit, against any pokemon with a defense stat of 1 and 4x weakness to Rock. According to this damage calculation formula, the damage dealt on the 5th turn (when Rollout and Metronome reach their maximum power) is 721,898,952. Over seven hundred million. One imagines that if a pokemon were to be hit with an attack of this magnitude, rather than merely fainting, both the target pokemon and everything else in a large radius would be reduced to nothing more than an expanding cloud of ash and a smoking crater.
To give you an idea of how ridiculously overkill this all is, the highest Hit Points a Pokemon can have is 714.
With the help of stat-increasing attacks and an accessory that doubles Attack, it's possible in some versions to get the Attack of a Marowak so high that it actually wraps around and becomes extremely low, thanks to a bug. That the bug is fixed in later versions only causes Marowak to become the EPITOME of overkill (1000+ Attack)... if it can survive long enough.
In a strange non-damaging example of this trope, there are early-game trainers of the Rich Boy and Lady trainer classes in Pokemon Ruby And Sapphire and Pokémon Emerald. They use Zigzagoon at level 7. The overkill is that, instead of using common cheap healing items like a normal Trainer would do to heal their Pokemon, they use the late-game Full Restores to do the job. For comparison: A potion costs 300, heals 20 HP and is readily available in any store. Full Restores cost 3000, restore all HP as well as remove any status problems, and are only available super late game. Keep in mind they're using them on Com Mons that are probably lower level than your starter by that point. Pretty overheal, isn't it?
In theory, the most damage that a Pokémon could do would be 202,786,432,200. Conditions do not yet exist to create this scenario, but a 255 base Attack Fire-type with Huge Power as an ability with +6 Attack, while running the maximum amount of E Vs, IVs, and Nature boosts could use a Fire-type version of Rollout after using Defense Curl and after maximizing out its held Metronome item, while two Cherrim are partnered to it in sunlight could get a critical hit against a Pokémon with base 1 Defense that has its Defense lowered to -6 and has no E Vs, IVs, and has a Nature decrease to Defense, when the Pokémon is Bug/Steel with Dry Skin as an ability and has been hit by Forest's Curse. If the move hits for maximum damage, it would be 202,786,432,200. That's over TWO HUNDRED BILLION. And at Level 1, depending on its base HP and its E Vs and IVs, the defending Pokémon will only have 11 to 17 HP to lose. Yeah.
The Worms series. Your enemy is down to the last worm, and standing on a ledge just begging to be poked? Nah... still got that Holy Hand Grenade!
Especially when you make a custom settings with explosions turned all the way up, and even more so with a third party program like Worms Armageddon's Fiddler which lets you monkey with just about every setting in the game. Letting loose with a high-explosive minigun is very satisfying.
By exploiting a bug related to the quick switching of weapons, it was possible to fire a minigun but use bazooka rockets as ammo. The typical result was, of course, blasting a tunnel through the whole map and killing everything in the way.
The Dinosaur King game features many attacks which very much appear to be overkill. One such attack involves knocking the opponent over and then literally stomping them into the ground. As that attack only gets that effect at a certain level of HP, it can be very satisfying if you've been beaten a lot over the course of the match. Others involve the opponent being set on fire, stomped flat, falling head-first from great heights, drowned, crushed by giant falling rocks, and being impaled on lightning.
The Final Strike from Mega Man X: Command Mission is designed for this. If you do enough damage to an enemy to reduce their current HP down to 25% or less of what they had previously with a non-subweapon attack without killing them, you can use the Final Strike which allows the player's party to initiate a barrage of shots and blows supposed to deal total damage way in excess of what is necessary, rewarding players for doing so with bonuses afterward. You can also do this to more than 1 enemy at the same time if you manage to hit several weakened enemies with a multitarget attack at the same time, and doing so increases the amount of time you can keep pounding away at them: this is also necessary to unlock some of the better FMEs for the FME Generator. Of course, against some bosses, 25% health is still a few % too many.
When Mega Man finalizes and performs the Red Gaia Eraser in Mega Man Starforce 3 Red Joker, he first fires off a laser of noise, which is more than enough to kill a weak boss, then the plates on his shoulders detach to perform a sweep beam, and it ends with a gigantic, field covering explosion. Nothing that isn't a major boss at full health should be left standing after this. In Black Ace, the Black End Galaxy involves throwing a black hole at the enemy, and then slicing them in half.
Heck, the third game's main combat gimmick is all about overkill. Overkilling an enemy raises your "noise" level by the amount you overkilled them with.
In Starforce 2, The Tribe King's LFB on a one hp Mettana.
In Painkiller, a great many of the weapons not only kill the enemies, but sends their limbs flying off in every direction in a shower of blood. Bonus points when done to a whole pack of enemies at once and double bonus points when done in slow-motion, and extra gold for juggling a enemies' dead body.
In No More Heroes, after hitting a mook enough times, Travis can perform a special move that decapitaes the mook, showering Travis in blood and coins. This becomes practical later in the game - said special move can also decapitate/split in half other mooks nearby, resulting in multiple showers of blood and coins. It's Crazy Awesome.
Once he's been knocked down to half health, Bonus Boss Henry gains an unbelievably awesome One-Hit KO move. Describing it would fail to capture the ludicrousness, so here's a link instead.
Surprisingly, Armored Core offers you a Sadistic Choice (at least in the early games) in terms of overkilling. If you shoot an enemy enough, it will burst into flames. Rest assured, it will die soon. However, until it actually explodes into nothingness, it can, and will, keep firing. Do you overkill it (which does speed up its death), wasting your ammo in the process (extremely important in some long missions without ammo boosts), or do you leave yourself vulnerable to its last attacks? Most players Take a Third Option, either by using a laserblade (which costs no ammo), or running away real fast.
The Novalith Cannon in Sins of a Solar Empire. Smaller worlds die from one shot, and the only way to survive two is to use the TEC-only Planetary Shield. The kicker? There's no possible way to stop a Novalith shell once fired even if you manage to conquer the target world and colonize it before your shells hit.
4X games in general seem to lend themselves well to practical demonstrations of this trope. Master of Orion II, for example, has a device that blows planets apart, a la the Death Star. For when you absolutely, positively have to kill every last living thing bigger than a microbe.
The Mercenaries series offers the choice of overkill, especially once more powerful airstrikes become unlocked. Sure, you could just run up to the target, shoot him, and then verify him, but it's much more fun to watch the entire city block he's hiding in get blasted to hell by a carpet bombing run.
In Mercenaries 2, you get the option to purchase a tactical nuke and use it against anything and everything.
It is mentioned that Mattias Nilsson, one of the playable characters, loves this trope, preferring to eliminate targets that would normally only require small arms fire with air strikes.
Overkill abounds in the RTS Rise of Legends. The secondary combat unit of the Vinci faction is a 15-foot clockwork robot that is equipped with a lightning gun, while their most powerful unit is something akin to a weapons factory with legs the size of tower cranes. The magic-wielding Alin have access to 50-foot golems built entirely out of glass, as well as crystalline spiders the size of tanks. Both smush enemies with little discrimination. The spacefaring Couatl frequently utilize some very large laser beams in combination with giant stone mechs.
In Dragon Ball Z Budokai 3, battles in the story mode and arena mode net you more experience points for finishing a fight dramatically. A signature energy blast move is good. A 30+ hit rush (possibly capped with a signature energy blast) is even better. A signature super move visible from space - which the game will never neglect to show you - is best of all. But being a Dragon Ball game, if you're not finishing fights like this anyway, you're not playing it right. For added effect, using an energy blast to finish things off will crack your opponent's HUD, while the super move will cause the thing to explode.
It should also be noted that most of these super moves visible from space will actually completely destroy the terrain as well, turning places like Namek into an equivalent of the Underworld, complete with lava and desolation for miles.
In Quake II, a downed enemy can be gibbed with enough firepower unloaded into his body, which may be advisable as sometimes a seemingly dead enemy will fire off some last shots at you.
Quake Live has an achievement for finishing off someone with 1 HP left with the Rail Gun, the most damaging weapon in the game.
In the remakes of Lunar: The Silver Star, the Final Boss has a beam attack that hits for over 7000 damage, when your characters can have a maximum of 999 hit points, and most likely have 500-600. This gives him a guaranteed One-Hit KO attack even against characters with protection against the Useless Useful Spell versions.
In Metal Gear Solid, in your fight with Vulcan Raven, he uses a gatling gun that he took from a F-16 to shoot you with, while the most effective weapon to use against him is a Stinger missile launcher.
In one of the joke scenes from Metal Gear Solid 3, The Boss uses the Davy Crockett nuclear missile launcher against Snake. At point-blank range.
Jak and Daxter didn't qualify until the second game, in which Jak got a Superpowered Evil Side possessing two kill-everything-on-the-screen attacks, as well as flickers of cool purple lightning that followed his attacks. Then he got a gun capable of firing a lightning orb that blows up every hovercar on the screen. Then the third game handed him an upgrade to this gun which burns through at least half of your ammo in one shot...a shot which is so large it gets its own mushroom cloud. As well as a variant form of his yellow gun which fires an Attack Drone that spams out ammo so fast it resembles a small but deadly rainstorm. Someone's really got to explain the concept of 'less than total destruction' to him. Ditto with Baron Praxis, who intends to stop the Metal Heads with a bomb that can blow up the universe! All of it! That's less like "overkill" and more like "omnikill"!
Arguably, it started with the Visibomb gun, a weapon that shoots a remote-controlled missile. On the right stages, you can stand at the beginning of a stage and shoot enemies clear on the other side of it.
The third game has the RY3NO. Fully upgrading this give you the RYNOCIRATOR, which burns every on-screen enemy into ash.
The RYNO IV (from Tools of Destruction) was banned in 59 galaxies, including the one that you're currently in, and the mere act of talking about it is grounds for being thrown into Zordoom Prison indefinitely. The original holoplan was torn into 12 pieces and thrown across the galaxy, so nothing like it could be built ever again (as Gadgetron thought it was too dangerous, and we're talking about a company that sells portable black hole launchers. To quote: "point away from face").
Obviously they didn't do a good enough job of discouraging the inventor, since A Crack In Time brought us the RYNO V. This was unanimously voted the weapon "Most Likely To End All Life As We Know It", outlawed everywhere, and, again, the plans were torn apart and scattered to the winds. The RYNO V is notable for having an inbuilt speaker system that plays the 1812 Overture whenever you fire it. Because, you know, when you've got that much firepower, why the hell not?
And then, somehow, the Plumber got his hands on some RYNO V plans, because by the time of Into the Nexus, he has created the RYNO VII, which is like the RYNO V, but with more missiles and bullets, a sleek purple and black trim, and the added bonus of playing Night on Bald Mountain, the perennial music of complete DOOM.
In Postal 2 after killing or crippling people, you can choose to do some of the most sadistic things to them such as chopping them to pieces with a machete, setting them on fire, smashing their heads with a sledgehammer, blow them to pieces with a rocket launcher, break every bone in their body with a blunt object, etc.
In Neverwinter Nights, it's common for casters to open locked and trapped boxes with Fireball spells. This is an incantation designed to clear rooms.
Incredibly annoying because of a Scrappy Mechanic that forces you to whale on a chest with your weapon coupled with chests that resist damage that would drop an ogre. Apparently, either locks must be picked or the chest utterly destroyed, because no one can carefully use a hatchet and prybar to open something.
This is also the game that, with the gore settings all the way up, things explode in a shower of blood and bones when you kill them with a critical hit. This also works when killed by Instant Death spells - Implosion and Destruction actually look like they are ripping people inside out when they go off. Implosion is Area of Effect, so if it hits few creatures, the result is usually a fountain of blood and bones.
Thanks to her AI being set to "overkill" by default, Qara of Neverwinter Nights 2 has been known to cast MeteorSwarm or Burst ofGlacial Wrath on one little orc. Annoyingly, this usually destroys nearby loot chests and/or kills you, if you happen to be in the immediate vincity.
In the original campaign, Shandra is impaled on an ice spike and set on fire before being blown apart by an Eldritch Blast. Note that this happens aftershe's already been sliced open and has lost a good pint of blood.
The expansion can let you completely obliterate someone from existence by ripping their soul out and eating it, which is completely different from the regular soul-eating ability in that whoever loses their soul this way can never be reborn. This is an ability you literally get in the last five minutes if you're really evil, and you only get to use it on three people: your former companions. Just as well, since it's incredibly hard to dodge and doesn't allow saving rolls to be made if it hits, which would make any campaign ridicolously easy.
In TRON 2.0, there is a subroutine (weapon) called the Prankster Bit. Not only is it a 1-hit KO (sometimes killing the player if they stand too close to the blast), but it can even get you a Nonstandard Game Over if an NPC is sucked in (it acts like the TRON equivalent of a black hole gun). Overkill in a situation versus one or two enemies (especially if they are Intrusion Countermeasure Programs, where a Disc Primitive will work, and can even block the opponents' Discs), but great when trying to kill multiple enemies at once. Also the best weapon in the final boss battle, against the corrupted fCon Team, where you have to derez them one part at a time. The Prankster Bit can take about 10% off their life bar per hit (again, watch that blast radius), but it drains a heck of a lot of your energy. A high Weapon Efficiency rating is recommended. The Cluster Disc works almost as well, at a fraction of the energy.
In the Hopeless Boss Fight at the beginning of Paper Mario, Bowser whittles Mario down to almost no HP... then hits him with an attack that does 10 damage, which is pretty high-powered for this game.
That's your entire health meter at that point in the game. At the end of the game your health bar maxes out at 65, using every badge you can find to do it.
Once Goombario is Level 2, he can use Charge. The player can have Goombario keep charging his power (provided Mario doesn't run out of health) until it is extremely high and overkill an enemy with Headbonk. The overkill can be even greater when Goombario is level 3 and can use Multibonk. This, incidentally, is especially useful against Huff N. Puff, if Mario is protected by Stone Caps.
In Super Mario RPG, a properly-used Geno Whirl will always do 9999 damage. The enemy with the highest health in the game has roughly 2000 hit points less than this (however, with the exception of Exor it can't be used on bosses).
The hip-hop-themed fighting game Def Jam: Fight For NY actually required you use stronger means than a normal punch to finish your opponent and end the match, usually in the form of high-powered combos, smashing your opponent into an element of the stage, hitting them with a weapon, or the oft over-the-top special moves. And that's not counting the stage where you can push them in front of an passing subway train...
In MadWorld, Jack can slam an empty garbage can over a mook's head. Then shove a road sign through his neck. Then grab and impale him on a nearby spike five times. Then he FINALLY dies. Or, you could just kill him in one hit with a chainsaw. It's your call, really.
In Baldur's Gate, a party member being reduced to enough hit points below zero prevents them from being resurrected, presumably because they've been pulverized. It's also possible to turn someone to stone or freeze them into an ice statue, then shatter it. For extra fun, petrify someone, then turn them back to flesh, then One-Hit Kill them. Oh, and if the Gore setting is on, when enemies take enough damage they explode into chunks of meat.
The Matrix: Path of Neo allows you to pummel an enemy, lift him up into the air to continue the beating, leap up and smash him into the ceiling, fling him to the floor, and stomp on his throat with both feet.
Eternal Darkness features a double-barreled elephant gun. Firing it without bracing yourself first will knock you on your ass. And yet it is not the most damaging weapon available even in that level, nor is one shot from it sufficient to kill most foes.
In Resident Evil 3: Nemesis, how does the titular Nemesis show the audience that He Can Thinkand that he's not one to be messed with? Rather than simply smash through the front door of the police station to chase Jill, the already practically unstoppable killing machine decides it would be better to go and arm himself. With a missile launcher.
Resident Evil 5's Hydra: The game's ultimate unlockable shotgun has three barrels side-by-side. Sheva has to wield it two-handed, but Chris and Wesker are so ridiculously ripped that they simply widen their stance and fire it with one hand at arm length. It has enough knockback potential to put any standard foe on its ass and does damage on par with a standard rifle at long-range, despite being...y'know...a shotgun.
How Albert Wesker is killed. Hit by two rockets, which explode him into a lake of molten lava. Justified, because his mutations make him immune to most conventional weapons at this point.
Max Payne has a rather different concept of this. Rather than you keep shooting mooks that are already dead (which you can), Max shoots a boss after he is clearly dead. Over and over again. He had to have emptied at least one magazine (which given his weapon, a Beretta 92FS, means at least fifteen rounds) into him.
Given that the boss in question (Jack Lupino) is really, really strung out on a drug that's known for rendering people oblivious to even the most crippling injuries, it wasn't an entirely unreasonable precaution.
Max Payne: When Lupino finally went down, I wanted to make real sure he'd stay that way. V was a bad monster, turned them into freaking zombie demons from outer space.
The Killer Suits in the stage "The Deep Six" empty their mags into a guy at the beginning in an effort to erase all evidence of Project Valhalla. One of them reloads and puts a final round into him before the other guy tells him "I think he's dead already."
A mod to the game let you wield a handheld minigun.
In 3 there's a slow-mo killcam when you kill the last enemy in a setpiece. You can keep firing to riddle the body with bullets as this happens.
Ace Combat 6: Fires of Liberation requires you to fly your plane down the barrel of the Chandelier cruise missile launcher. Yes, a launcher with missiles so big you can fly a plane down its barrel. If a missile is launched with the plane still inside, well, "One-Hit Kill" is putting it... lightly. On the player's side, it's easy to single out a single target for all four or six special missiles, pop off the heaters and loose a few gun rounds as well. Or feed a single, isolated ground target a FAEB/LSWM/MPBM, all weapons meant for wide-area devastation.
Ace Combat 5 also has this with the Falken's Tactical Laser System, and Zero has the one on the Morgan.
Ace Combat Infinity includes an "Overkill" score bonus for killing enemies in this manner (e.g. hitting an enemy ready to die from a single cannon round with a pair of missiles, or hitting someone with a missile after a teammate's killed him).
Air Force Delta Strike pits the player against the Leupold battery of gigantic rail-guns, so large you have to fly down the barrel. The barrel is actually five separate railgun barrels built as one. You have to maneuver your plane between shells, depending on which barrel is about to fire next. The enemy has three such railguns that you have to take on in that mission.
Soul Calibur 4's Critical Finish. Also the fact that in Arcade Mode, you get extra points for hitting the downed corpse of your enemy when you win a round.
The Touhou fangame Touhou Soccer is basically Soccer played with additional rules that permits the use of spellcards or youkai powers on the ball. This results in excessively spectacular, SRW-style danmaku barrages on the unfortunate ball. For example:
The Scarlet Sisters use their weapons, Laevatinn and Gungnir, in addition to their danmaku techniques, for their combination attack.
Yuuka, Marisa and Mima all nuke the ball with several permutations of the MasterSpark.
Marisa in particular has a combination technique, where Alice and Patchouli cast buffs on her before she does a very good impression of Thrugelmir's Blade that Cleaves Continents that even shreds the spectator stands. Thankfully for the audience, spellcards only inflict all non-lethal damage...
Inverted in Cirno and Letty's combination strike. Cirno moves to blast the ball with her Icicle Fall (Easy) spellcard, apparently forgetting that it can't hit anything directly in front of her... like, say, an oncoming soccer ball. The ball proceeds to hit her in the face - not once, but fifty bajillion times, making it a rare case of overkill from the target to the attacker. Though, to be fair, it's still a good hit and the ball can rebound and score a goal.
Also, Rinnosuke's (MANnosuke! NICE COMBINATION with Tokiko. He kicks the ball hard, into the poor youkai's face, then it rebounds into the goal. It's one of the strongest moves in the game.
And then there is this from Mima just a little bit stronger than the above move enough that is the most powerful single shot in the game. Yes, it is entirely necessary to orbitally bombard a hemisphere to hit a soccer ball.
Hilariously inverted with this one by Hong Meiling.
On the PS3/360 versions of Sonic Unleashed, the Nightmares (the regular, almost lizard-like enemies) have a dying animation which takes a few seconds. It begins with the Nightmare standing, then it slowly collapses until it dies. However, if the enemy gets hit at any time in this animation, it resets. You can make Sonic the Werehog do quite the overkill, especially when all your stats are fully levelled up, and you just whale on an enemy long after it's dead, working up a huge combo, then giving it an uppercut and smashing the enemy into the ground full force. It's up to you whether this example combines with Video Game Cruelty Potential.
The bottomless pits; just smash the hapless enemies off the edges and watch them fall and die.
Smooshing enemies into pancakes with your hands. It's especially fun when you get into the higher-level comboes. One-two punch, followed by smashing it between your two giant fists, followed by a powerful spinning backhand, followed by grabbing their ankles and slamming them into walls and the ground repeatedly....
In Prototype, it's possible, as shown even in the early trailers, to grab someone, jump on a high building (the Empire State Building, for instance), then jump, grab the person you were holding, crash it to the ground, grab it again, jump, crash into another floor, grab, crash, grab, and all the way to the street-level.
Not to mention other horrible things you can do. Punching through 5 people at once? No problem. Grabbing a helicopter with a whip, hijack it and use it as a landmower (where grass = people on the sidewalk) or simple jump in the air, land on someone, use his body as a skateboard and kick his corpse into a wall or a car, splatting it into tiny pieces. Or just jumping at the center of a crowded street and kill everyone with a burst of tentacles or spikes coming from beneath the ground.
Lets just say this entire game is based around overkill. Even the military needs to use overkill just to put a dent in Alex.
If you keep on attacking your opponent even after they are long gone, BlazBlue will actually award you a trophy for it: "It's The Only Way To Be Sure."
If you turn "show damage" on and perform an Astral Heat in training mode, you'll see that an Astral Finish can do up to 20,000 damage. The highest HP character in the gamenote except Unlimited Ragna has 13,000 health (Tager), and will likely have only 2,000 left before you can initiate an Astral Heat.
Ragna, with his Astral Heat, slices the opponent with his Sinister Scythe, then transforms into... something... and then erases the target from reality. Really.
With Haku-men's Astral Heat, Akumetsu, the screen is so filled with blood that it turns black for a second.
If punching a sucker in the face so hard it leaves a fist imprint in the soon-to-be-shattered moon doesn't qualify as overkill, then Makoto's Astral Heat (Planet Crusher) is doing something wrong.
The final boss of the first game, Nu-13, summons a BFS a few hundred feet long and a dozen or so feet wide with her Astral and proceeds to stab the opponent in the face with said sword (seen from her victim's pov, none the less). The final boss of the sequel, Mu-12, has a reworked Astral in the third game with which she summons eight such swords to stab the opponent with. And thenthe swords explode.
God of War, specifically Theseus' death in the 2nd installment.
Ragnarok Online has a job build for Monk, which uses all of your SP for a single attack, also preventing SP regen for a few minutes afterwards. These builds usually result in someone dying, as monks are rather squishy.
This build is the main reason Monks have their reputation as boss killers.
Doom was probably the first game ever to make overkill somewhat worthwhile, by introducing us to Ludicrous Gibs.
Rise of the Triad, an Apogee game that was released around the same time Doom was, included several weapons with ridiculous amounts of explosive firepower such as the napalm-laden Firebomb, the six-missile-overkill Drunk Missile, and the Dark Staff. Any one of these weapons could be found on the first level. Not only would the enemy be gibbed upon contact, but any surrounding enemies caught in the blast would also be wiped out, and in extreme cases, gibs would stream down the screen, with an accompanying message "Ludicrous Gibs!" displayed at the top-left corner. Needless to say, these were long-distance weapons, and any player too close would be thrown into the air and most likely be killed in the blast.
Singularity Planet Busters from Sid Meiers Alpha Centauri. For when you really need to turn the heartland of an opposing faction into a vast water filled crater.
The killstreak rewards in Modern Warfare 2's multiplayer include everything from AGM missiles to airstrikes to carpet bombing runs to a Tactical Nuke that instantly kills everyone on the map, cannot be stopped or avoided (except via EMP, the second highest reward), and ends the game in victory for your team.
Empire Earth includes an epic version of the age progression present in the Age of Empires series. Once you get your first level of rifle infantry they are utterly devastating compared to the previous tiers of footmen, but of course, military superiority altogether can be taken to absurd levels depending on how fast you can rise through the eras relative to your opponent. Are you nuking individual cavemen?
With the ability to summon anything, Scribblenauts is rife with opportunities for this. Park full of trash? Use a black hole. Bee attacking you? Time for a minigun. Defeat a barracuda with Cthulhu! Summon God as your personal bodyguard! And so on...
EVE Online: Records show that the top usage of Titan Doomsday Devices for December 09 was the destruction of Battleships. A Titan Doomsday Device does up to 3 MILLION HP of damage and never misses. The theoretical maximum HP of battleship (factoring resistance to damage) remains under 600 thousand HP.
Homeworld's capital ships were heavily armored. The concentrated fire used to kill them off quickly commonly involved 10-50 capital ships, each firing 1-4 enormous ion cannons at the same target. The last few missions of the original game could involve hundreds of ships concentrating fire on a single target.
In the last mission of FreeSpace 2, the genocidal Shivans invade and destroy an entire star system in what can only come across as a literally astronomical dick move, given their enigmatic motives.
In Sacrifice, nearly all of the most powerful spells fall under this trope. In particular, the spell that summons a volcano, or the one that causes a giant circle of ground to fall away. The spell that vaporizes a target unit's intestines for a one-hit-kill & gib may also qualify. A similar spell achieves the gib by dropping a giant cow on the target from several hundred feet in the air.
In The World Ends with You, the power of a Fusion is determined by three multipliers: Attack score, the Difficulty setting, and a power score unique to each fusion. Shiki's strongest fusion has a multiplier of 20 (10 more than her 2nd level). Beat's third level fusion has a multiplier of 30. And Joshua's third level fusion has a multiplier of 99.99. Fitting, since it does "drop the freakin' moon".
Minamimoto's ultimate technique: Level i Flare. A bit of explanation: Flare spells hit anything whose level can be divided by the Flare's (so a Level 4 Flare can hit level 4, 8, 12, etc. enemies, and a Level 1 Flare can hit anything). For those who aren't math geeks, this means that the Level inote i being the square root of negative 1] Flare hits anything and everything, including imaginary and/or complex targets. Overkill indeed.
The M-920 Cain heavy weapon in Mass Effect 2. Its nickname is the "Nuke Launcher," though technically, it's only firing a small piece of metal at relativistic speeds. Either way, it causes a big boom. Using it against the toughest bosses practically kills them outright. Using it against weaker enemies is the very definition of overkill. There's also the downloadable M-490 Blackstorm Projector, which basically creates a miniature black hole that draws in nearby enemies until it collapses explosively.
The sheer amount of resources that the Reapers have poured into neutralizing Commander Shepard is simply awe-inspiring. Given that s/he's killed a few of them,it's a bit justified. Hell, Harbinger's first shot in 2 was to have your entire ship blasted into scrap metal.
Taken even further at the final confrontation in Mass Effect 3. When Shepard leads a charge on foot on the teleporter that will take him/her to The Very Definitely Final Dungeon, Harbinger tries to shoot Shepard personally with its massive ship-killing Wave Motion Gun to prevent that from happening. It even hits, but still isn't enough to completely kill Shepard, who continues to crawl and limp the final meters. To put another way: a two-kilometer tall dreadnought specifically designed to fight entire fleets singlehandedly descends from orbit for the sole purpose of stopping one on foot soldier from entering a teleporter.
The Widow Sniper Rifle, which is designed to pierce tank armor. If you use it in Mass Effect 2, you'll primarily be using it against infantry.
The Citadel DLC has a cutscene where Shepard covers the squad as they climb a ladder. Afterwards, Shepard is cornered by a grand total of about 4 enemies. Everyone (about 10 elite troops) leans over the balcony and unloads 200 rounds into them and the ground around them.
Wrex: That's why I love hanging out with you guys! Why shoot something ONCE when you can do it 46 more times! Javik: I find what primitives lack in aim, they make up for in ammunition. Liara: I dunno.. are you SURE you got them all? Garrus: And that's the moment when the universe ran out of ammunition!
This is also how Colonist Shepard's parents were killed. They tried to fight back, so the batarians hit them with an artillery strike.
Two of your primary sniper teammates - Garrus and Thane - have this listed as their preferred way to take down krogan. Most of Thane's elimination techniques boil down to Neck Snap; with krogan he has to reenact the boxing scene in Sherlock Holmes with added violence to deal with the secondary nervous system and so on (with alternate option: "Bomb"). Garrus, meanwhile, preferred to use Death by Irony - shooting a gunrunner with a smuggled weapon, hurling dangerous drugs into the eyes of a drug smuggler - with the exception of one person, almost certainly krogan, who required being shot everywhere and third-degree burns.
In an on-ship dialog, Grunt voices the opinion that this is a sign of respect.
Grunt: I won't disrespect their strength by doing less than the worst to them.
With a sadistic Random Number God controlling everything from behind the scenes, you'll see a lot of Overkill in Fire Emblem. So you hacked away at that boss's HP, leaving them with exactly 1 HP left? Well, the next unit to attack, which if it would crit (despite having a mere 1% chance to do so) would kill the boss from full HP... promptly will crit. Of course, if your plan is to leave the Boss with a minor bit of HP, so a weaker unit could kill it, the second attack of whatever unit you had sent into the fight to weaken said boss, also will be a crit, killing the boss immediately. Or when your unit did their first attack, leaving the enemy with a minor bit of HP, then they take the enemy's counterattack... that's when the Crit will come. Of course it all works in reverse. The enemy won't kill your unit practically. They'll crit and overkill you.
The sacred weapons from Sacred Stones get x3 bonus when fighting a monster. Crit with that, and that can do damage upwards of 150 damage, easily. When your characters' health all max out at 60, it's not uncommon to one-hit-kill an enemy 3-4 times over. And of course, the above rule applies as well.
Give Joshua a Brave Sword, and, taking the damage he would do against the average enemy, 25 damage, and with his high speed, he would hit four times, giving you 100 damage. Of course, this being Joshua, he will have very high critical chance, leading to a possible 300 damage in one turn. Then if you get Tethys near him, allowing him to move again, he will be able to do a grand total of 600 damage. Per turn.
Along the same vein are the mastery skills from Path of Radiance and especially Radiant Dawn. In the former, you have to use up a lot of skill capacity points just to learn them and you only get 4 opportunites per game, but the masteries that inflict damage cut through enemies swiftly whenever they kick in. But lordy, Radiant Dawn is a whole other beast: all units that promote to tier 3 (and Laguz that use a Satori Sign) get a free mastery skill, and they are ALL made of Overkill. Only one or two of them don't inflict 3-5x more damage, and some have a side effect (put enemy to sleep, ect.) that you're not liable to take advantage of because your hapless victims will usually become Deader Than Dead first.
Luna (in Dawn) triples the user's Strength, then negates the foe's Defense, then usually crushes its' victim in one stroke. More or less, there's not a unit in the game that can survive that. But! If that's just not Overkill enough for you, consider the Black Knight's obscene mastery, Eclipse. Same effect, but 5x Strength instead. Based on the Knight's stats, he has a fixed 40% chance to inflict 208 damage. The final boss is 88 HP short of that. Ye gods. Fortunately, when it comes time to duel the Knight in the final chapter, equipping Nihil shuts down Eclipse (and any other enemy mastery) altogether.
Trueblades' mastery skill, Astra, allows them to make five attacks instead of one. And with their high Speed, they're very likely to double attack. Give them a Brave Sword and the Adept skill (which causes a unit to attack twice instead of once if it activates), and it would be theoretically possible for them to attack forty times in one battle. And then you add in their high chance of getting a critical hit...
A "Ruin Sage Morgan" (skill build for Morgan as Aversa's son where he's a Dark-wielding Sage equipped with a forged Ruin Tome)— a theorized character in Fire Emblem Awakening... embodies this trope: 75 ATK (Magic) with 100% chance of activating vengeance, which can depending on his HP, raise that to 114... and he's got a 100% chance to critical. 342 Damage is quite painful in a game where the maximum HP is 80.
Most of Ar tonelico's Song Magic isn't quite so powerful. But then we come across Tower Connection, Silver Horn, Ar tonelico, and Phantasmagoria. The latter two in the second game fire a concentrated laser at the Floating Continent you're on, which causes an explosion larger than the continent itself. About 100 times larger. Combined with Replakia, which is itself another huge freakin' laser much closer to the continent than the titular tower, and it's a surprise the same thing that would happen to Lyner if he used Ar tonelico?? doesn't happen here.
In Spider-Man 2, you could climb the highest building in the city while holding a thug, then jump off and piledrive the thug to the ground. In fact, this is the only way to jump from the top of the Empire State Building to the ground without dying.
Transcendence actively promotes this in dealing with the massive capital ship enemies encountered near the end of the game. Of particular note is the Iocrym Fracture Cannon, a weapon that launches an unending torrent of very damaging plasma, which at this stage of the game is essentially one of the two most damaging types of damage. It can then be upgraded to do 350% its original damage rate, which is more than enough to destroy anything in the game.
This can also be accomplished with jettisoned crates of fuel; putting enough fuel, or ammo, into an unlimited number of crates and then shooting them will create a massive chain reaction of thermonuclear explosions, killing anything viewable in screen with absolute certainty, and beyond, depending how widely spread the crates are. In theory, one could do this to an entire star system, frying everything instantly and completely.
In Urban Rivals, Darth of the GHEIST Clan is noted of being too good of a killer, as he is known for using hundreds of bullets, when three would have done, or also using a bazooka at the drop of a hat.
Barbatos from the PS2 remake Tales of Destiny. His trademark "No Items Ever!" mystic arte is practically guaranteed to deal five digit damage regardless of your stats (In a game where the player HP cap is 9999), and his World Destroyer can easily break into six digits range if it's not stopped. Plus, when he gets low on HP, he uses Violent Pain, which increases his attack power dramatically for even more overkill. This in conjunction with World Destroyer and the deliberate use of equipment that increases damage taken can actually make him hit you so hard that the damage loops back around into the negatives.
In his first appearance in Tales Of Destiny 2, he lacks his trademark hi-ougi, but on higher difficulties, will use Execution and extend it into the absurdly overkill Luna Shade spell in response to item usage, which can hit for five digit damage at a point where you'd likely have slightly over 1K HP.
On a general Tales Series note, getting hit with a mystic arte/hi-ougi from a boss on the highest difficulty will generally deal damage that exceeds your current HP maximum by a significant degree if you're fighting them at the appropriate level.
In Persona 3 and Persona 4, if one of your characters uses a normal attack and lands a critical, they usually strike the enemy so hard or so many times, he not only gets massive damage but also is knocked down, in Persona 4 for more than one round. Kanji is probably one of the best examples - his critical attack consists of throwing his chair/board/shield at the enemy, kicking him and punching down to the ground. Mitsuru is also similar, she strikes an enemy vertically, launches a barrage of swift strikes and curb-stomps him with boots on high heels. No wonder everyone is afraid of those two characters.
The bonus bosses from both of those games like to indulge in overkill, too. If you attempt to, in any way, null any of their attacks, and also after a certain number of turns regardless, they will cast a powered-up Medigolaon which does 9,999 to the whole party. Now consider the fact that your HP is capped at 999...
The final boss of Descent II features a colossal green robot that is completely invulnerable to all frontal attacks and sports dual rapid fire homing earthshaker missile launchers that he uses quite liberally. The earthshaker missile is a fusion of the smart missile and the mega missile turned Up to Eleven. In mere seconds of him spotting you, you can expect to have anywhere from 2 to 10 shaker missiles quickly closing in on your position. God help you if they miss.
Assassin's Creed: Brotherhood isn't quite as over-the-top as many examples on this page, but one move has to stand out - stabbing a guard through the underside of the head, then firing the Hidden Gun at point-blank. The former would be a fatal wound in Real Life, and remember that the latter can punch through Brute plate for a One-Hit Kill even at maximum effective range. At point-blank, one wonders why the head doesn't explode or get sent flying.
In The Godfather games, after choking someone to death, Aldo or Dominic seals the deal with a Neck Snap. You can never be too sure, right? Some of the other Execution animations also involve this. For one, the machinegun Execution on a standing target involves hitting him with the weapon butt twice to knock him down, stomping on his neck and then giving him a belly full of lead.
Sin in Final Fantasy X. Eventually, your team pisses it off so much it is provoked into using Tera Gravitation to kill you. The attack in question pulls debris in from the Moon, and gouges enormous fiery rifts in the planet's surface that can be seen from outer space. All this, to kill a piddly ship with some two-legged gnats on (read: you). It's a testament to how resilient your party is that they do not get turned into vapor by that. Or maybe they are simply that lucky...
Actually, it uses Giga-Graviton to finish off your party if your piss it off enough. And Tera-Graviton was actually mis-aimed by the one controlling it so it doesn't actually hurt you. One of the Bonus Bosses actually uses Tera-Graviton as an attack, and...it can never kill you. Weird.
The Kingdom Hearts games are known for absurdly difficult bonus bosses, but the Unknown in Birth by Sleep takes the fucking cake. Virtually every attack he's got will reduce you to 1 HP regardless of level, which includes each individual hit from his overly long combos. Get hit with a full combo, and you'll be stunned, aka, deader than dead. Many of his own attacks consist of the most powerful deck commands in the game cranked up to eleven, and to make matters worse, if you do manage to land a good combo on him...he'll just reverse time and proceed to school you. There's Overkill, and then there's the Unknown.
In Call of Duty 4's Death from Above there is nothing more satisfying than using the 105mm to kill a single enemy soldier just because you have the time.
Strangely enough, a reflection of Real Life. You can find several videos of AC 130 missions on youtube; in at least one of them the gunship is shooting at a lone infantryman who keeps evading the smaller shots by zigzagging around (he only succeeds because the time-to-target is several seconds). Then the gunner gets bored and/or irritated enough to fire the big gun...
In Halo: Reach, there is a Wave Motion Gun usable in the climax. It can One-Hit Kill a Covenant battlecruiser if timed right. It can also be used to kill the incoming Phantoms, which can usually only be killed by tanks or dozens of rockets. There are also Banshees there, which are Glass Cannons. Lulz ensue.
On the topic of tactical bombings, there is a Target Locator. It rarely ever appears, but when it does, it fires bombs the size of enemy units. Firing this upon large crowds of Grunts can prove very pleasing.
In the Penny Arcade Adventures games, killing someone with an overkill causes you to kill them in slow motion, and then get a +5% damage bonus. This goes all the way up to +75% in each game, per character.
The Last Remnant has a special combat effect just for that called, guess what, Overkill. It requires someone to be hit by an enemy with about twice as much damage as the defender's HP. While hard to perform on bosses and players, normal creeps often succumb to this. Overkills usually are so powerful, not only the entire Union dies (Unions share HP - if one person gets hit for 3k damage, entire group is as well), they are blown away like a rag-doll or disintegrated if it was a spell.
In Sly Spy, the player fights a shark as a boss. After killing it, it's possible to keep shooting at it before the level ends, turning it's corpse into a bloody mess.
In 3D Dot Game Heroes, fully upgrading the Giga sword causes the blade, when on full life, to blanket the screen, destroying pretty much everything in its path, even making boss fights on the hardest difficulty mode a cakewalk.
In The Elder Scrolls III: Morrowind the player can become this by exploiting the ridiculously broken alchemy system. The effectiveness of the potions is determined by intelligence, and you can make potions that increase it. Do this for a while and you'll be making potions so powerful they literally break the game: "Fortify Attack" and "Fortify Strength" can, at this point, allow you to kill the second form of Dagoth-Ur in one hit even though he is scripted to be invincible, and "fortify speed" makes you so fast the game's physics screw up, letting you run through mountains.
Trigger Knight has the purchasable consumable Divine Edge. It multiplies the damage that your next attack does a thousand times, ensuring that whatever you hit is dead. Even the dragons, which are nigh impossible to otherwise kill.
I'll explain. The Skirnir missile frigate has eight launchers for Shadow missiles. Shadow missiles have eight warheads. Each warhead does 755 MJ of damage. The two toughest ships in the game have a maximum of 12 GJ of shielding. Do the math.
Oh, and did I mention the damn Shadows will seek new targets if the old one is destroyed before they hit????
A milder version of this trope comes in the form of the corvette-grade Typhoon Missile. An eight-warhead missile dealing 240 MJ of damage total (each warhead does 30 MJ of damage to stack up). Why is this considered overkill? Because no vessel below the class of M6 corvettes carries 200 MJ of shielding, with the only exceptions being the Argon Eclipse and a few models of the Teladi Falcon, namely the Sentinel variant (the only non-capital ship in the games to mount 400 MJ of shielding or 2 200 MJ shields). While the ones with turrets can at least try to swat off the missiles, one volley is enough to vaporize anything that doesn't come with a turret, and just two or more can easily overwhelm the turreted ones. The missiles, however, can't catch M5 scouts, as they're just too vexatiouslyquick to draw a lock on.
The Saints Row series has this happen every so often.
When your "Wanted" rating gets high enough, whether from a gang or from the police, they send out the big guns, possibly for just one man. These "big guns" can include genetically-engineered supermen, a Flechette Storm of grenades, a girl who can Flash Step while Dual Wielding Uzis... and a tank.
In Saints Row 2, Mr. Sunshine, The Dragon to the General of the Sons of Samedi, seems to take a lot of bullets before dying—and even gets up after the first salvo. You wind up decapitating him and throwing his head on a conveyor belt leading to a furnace to make absolutely sure.
If you let the statue in Steelport get blown up in Saints Row: The Third, the paramilitary group that has declared martial law deploys a massive flying fortress to scrub the town in order to get rid of you once and for all.
Some of the weapons you can get tend to qualify for this as well... employing a rocket launcher against a single person or even a car, calling an airstrike against someone, deploying a drone to fire a missile at one person... overkill is just another day in the office in Stilwater.
An interesting moment happens in SD Gundam G Generation GATHER BEAT and its remake SD Gundam G-Generation ADVANCE. At one point, you face the Frost Brothers armed with a series of Gundam Xs, one of them piloted by Tiffa Adill. If you played things right, you can actually kill the Frost Brothers three times, all of them scripted moments. The first comes if you had recruited Garrod Ran, who will convince Tiffa, rescue her, take over her Gundam X and turn its Satellite Cannon on the Frost Brothers. The second involves Cucuruz Doan, who will be taught a Super Mode by Domon Kasshu and attack the Frost Brothers with his newfound abilities in a Zaku. The last one involves Kamille Bidan losing control of himself and chopping the brothers with the Zeta Gundam's BFS.
A mod for StarCraft makes the Terran Siege Tank fire nukes. 'Nuff said.
In Infamous, you just restrained an enemy that's been pissing you off and you want revenge? Use a freaking Lightning Storm on them.
The Taiidan Emperor in Homeworld loves it, but can't always pull it off. The first time happens during a cutscene, when the planet of the Kushan is hit with weapons that burned its atmosphere off, just for a violation of a treaty so ancient that the Kushan didn't even remember it existed. Then in mission 15 the Taiidan attack the Mothership by throwing a gigantic asteroid at it and escorting it with one of the most massive fleets they ever fielded. The kicker? The asteroid was just a distraction to assemble an overkill fleet for the final battle.
In Borderlands 2, the Gunzerker class has a skill with this exact name. Whenever the player kills an enemy with a weapon, the excess damage from the last kill becomes bonus damage on the next weapon attack, potentially leading to a constant string of overkill.
Downloadable character Krieg the Psycho has a skill called 'Bloodsplosion,' which causes enemies to explode when killed...and enemies killed by that Bloodsplosion add overkill damage to their explosion. And so on, and so on, and so on. It only stops when there are no more enemies in range of an explosion. It's possible to string a long chain of these explosions sufficient to wipe out any boss that makes the mistake of summoning swarming enemies.
In City of Heroes, if you fail the "burning building" zone event, the building explodes, killing you. It was supposed to deal three ticks of 1000 points of damage, just enough to defeat the strongest characters — but the person designing the explosion accidentally specified it as "1000% damage", meaning 10 times your maximum hitpoints. They left the error in because, well, it got the job done.
In Defense of the Ancients and the sequel DotA 2, hero named Axe has an ultimate called Culling Blade. It deals low (150/250/300) magical damage on healthy enemies, but if it lands on a target with health below ability's stated threshold (300/450/625), it instantly deal 100 000 000 physical damage, but not before removing all buffs from the target to stop anything that might save its life. When upgraded with Aghanim's Scepter, ability's cooldown is lower from 75/65/55 to just 6, meaning he can potentially deal 500 million damage if he gets to ult everyone on enemy team.
In ∀kashicverse: Malicious Wake, you yourself can turn into a massive entity with power equal to a boss. The most powerful attack you have in this form is a laser with enough range and power to literally kill everything onscreen. You can only use this for a few seconds before reverting to your normal form, but it's powerful enough to drain whole health bars of bosses in mere seconds.
In Mario & Luigi: Dream Team, a level 100 player (aka ridiculous overleveled) can go against the weakest enemy in the game (a Gromba), use the time freeze badge combo, then by having the Duplex Crown (for two attacks per turn) unleash Zee Egg and Star Rocket on said enemy non stop for the equivalent of six attacks. The overall damage? About 99,999. That's twelve thousand times the enemy's health, and enough to defeat the final boss 41 times over. Ouch.
In Stellavanity, if you play as a character's S-Type, you can use their Assault attack on weakened enemies to obtain "Overkill" bonuses. Do it on several enemies at once for a "Multikill" bonus.
World in Conflict multiplayer is half teamwork, and half using limited resources efficiently:
A low-cost tactical aid like the tank buster or airstrike can destroy heavy tanks at full health, but their area of effect is relatively small and must be precisely placed. Overkill comes into play if a player decides to use expensive daisy cutters, fuel-air bombs, heavy artillery barrages, carpet bombing, or nukes on a disproportionately small number of units, or units already about to be killed conventionally. Laser-guided bombs are moderately expensive and have a tiny AOE (but they are good at leveling buildings), so using them directly on any unit is overkill.
Aside from tactical aids, players can also target infantry units with munitions really meant to be anti-vehicle, such as heavy artillery (usually earning a fitting report from the artillery crew, such as "Infantry was annihilated.") or a heavy tank's HEAT shells (which will always kill exactly one soldier).
In Tomb Raider Underworld, Natla proves to be resistant to many things and it seems only two things can kill her: Thor's Hammer (the most powerful weapon in the trilogy, which can kill demigods), and eitr, which kills instantly anyone who falls in and reanimates their corpse as a Thrall. Guess how Natla dies? Lara hits her directly with Thor's Hammer, and she falls into the eitr! (Although she gets better in the DLC extensions)
Red Dead Redemption: How the Army kills John Marston in the end. In fact, the fact that Ross sent the Army against one man is an example. In a gameplay note, try duelling with the Mauser sometime. Oh, the carnage.