In a game which relies heavily on numerical statistics, particularly an RPG, a character will have a chance of doing noticeably increased damage with an attack if the right number comes up. The likelihood of this occurring may or may not be affected by the aforementioned stats, and sometimes magic may be given this little perk as well. Sometimes this is accompanied by different damage text or special effects (which may be more than just graphics). There are two general methods of handling critical hits: In the first method, they simply do extra damage, usually multiplying the base damage by some number. In the second method, random results are generated from a "table" of possible effects, which range from extra damage to Subsystem Damage to instant death.
In most games, no explanation is given. The assumed meaning is, usually, that the attacker managed to hit just the right vital organ or structural flaw with just the right force or speed. However, most of the time an explanation will come across as a Hand Wave to varying degrees.
This differs from Elemental Rock-Paper-Scissors in that it usually applies to element-free attacks (i.e. physical attacks), although elemental attacks can have this effect as well if luck permits.
Maximizing the chance of one is a favorite goal of the Munchkin and those who practice Whoring in general, due to the (usual) lack of drawbacks. Said coveted Luck Statmight fix that. However, despite this Power Gamers despise it, as they do any sort of luck, and seek to eliminate it whenever possible, often resulting in Stop Having Fun Guys. Hilarity then follows.
A Critical Hit Class employs this to get the best possible outcome. Boom, Headshot is a similar trope applied mainly to First Person Shooters, although that involves skill rather than luck. Not to be confused with the Podcast of the same name. Contrast Critical Failure.
The best known is, of course, rolling a "natural 20"note That is, a 20 on the die, before applying modifiers. in combat did bonus damage — this started out as a common house rule which became an official option in the 2nd edition.
In "AD&D 2.5" beating an opponent's AC by 4 or more meant at least double damage, and the detailed damage option introduced to avoid "Only a Flesh Wound" effect added injuries if the target fails an extra saving throw. Like major bleeding — or beheading, depending on the weapon's size, type and severity roll. The same for saving throws against spells failed by 4 or more (i.e. an acid arrow may melt one's arm off) with area-affecting spells possibly injuring several locations — i.e. surviving a fireball may still mean that one's eyes and right leg are fried crispy.
The 3rd Edition allowed critical successes under other circumstances as well, and had weapons with different odds of critical hits. A "natural 20" no longer resulted in an automatic critical hit, either, but did mean an automatic hit and a chance to "confirm" a critical hit with a second roll.
Unlike most examples, in D&D, creatures with odd anatomies can be immune to critical hits, including Golems, most kinds of undead, and Blob Monster. This is because D&D justifies critical hits as being regular attacks that hit an unprotected point or vital organ. Undead and Gelatinous Cubes obviously lack vital organs and therefore can't be hit for critical damage.
The D&D 3.5-based Star Wars RPG took it one step further, making critical hits instant-kill faceless Mooks and deal (on average) about 1.5 times as much as maximum damage with whatever weapon you were using.
4th edition Dungeons & Dragons has all creatures affected by critical hits. All weapons deal max damage on a crit. Magical weapons and some heavy weapons deal extra damage on top of that. However, all weapons deal critical damage on 20s alone again (except when augmented by certain powers or feats).
Rolemaster had pages upon pages of critical hit tables. It was famous for them. Overcoming your opponent in a battle in Rolemaster isn't so much about draining their hit points but landing criticals. Each attack consists of an attack roll (adding your skill bonus for the weapon you're using and subtracting the enemy's defensive bonus), and if the weapon's attack table indicates that you get a critical hit you roll for the critical (the severity of which depends on whether your hit resulted in A, B, C, D or E criticals) and see how well you succeed in that critical, the results of which range anywhere from small wounds to smashed skulls, so the criticals play a... erm, critical role in resolving a combat.
Warhammer Fantasy Roleplay has the "Ulric's Fury!" (shouting it out loud when you get one optional), caused by rolling a 10 on a damage d10 and succeeding at a weapon skill check that allows you to roll another d10 for damage. And if that one comes up a 10 too, you keep on rolling, stopping only after you roll something other than a 10. The rules also have a 'critical hit', which is a hit that takes place once your opponent is out of HP and actually gets a permanent injury (or death) from an attack.
The 40K version, Dark Heresy, has the same thing (only it's now called the "Righteous Fury!", and isn't nearly as fun to shout). There're also actual critical hit tables, like Rolemaster but much more fun. You can see scans of them on 1d4chan.
Warhammer has a few of them itself: Irresistable Force, a critical success at casting a spell that means it can't be dispelled (contrast with Miscasts); Poisoned Weapons which will always wound on a critical hit roll; and the Killing Blow skill which auto-kills on a critical wound roll. One magazine article suggested a critical success house rule for psychology tests, as well, to represent the small chance of warriors holding out against impossible odds.
In one of the previous Chaos Space Marine codexes, the Axe of Khorne granted the wielder an extra attack for each roll of 6 that came up to hit. And if any of those came up as 6. With no upper limit on the number of extra attacks. This could lead to entire squads of Terminators being chopped down by one really pissed-off guy with an axe.
Leadership tests in Warhammer 40,000 (one of the few rolls where rolling less is better) automatically succeed when a double one is rolled, in spite of any penalties or debuffs that would require to roll 1 or less. Psychic Powers use leadership tests where double ones and double sixes cause miscasts: The rules explicitly state that when rolling a double one, a psyker manages to cast the spell even if it kills him.
The Six Edition has "precision shots" rule for Characters, that allows them to shoot at a single model rather than the whole unit if they roll a 6 to hit. Also, "rending" weapons wound regardless of Toughness and ignore armor saves when rolling 6 to wound.
The New World of Darkness has two versions of this, both of which apply to all sorts of rolls, not just combat. Players roll a "dice pool" and every die that comes up with an 8 or over is a success; if a die rolls a 10, that die is re-rolled, and if it gets another 10, it's re-rolled again, and so on (with certain equipment, spells, and so forth, this rule can extend to 9s and 8s). Furthermore, if more than five successes are scored on any one roll, it's considered an exceptional success, which means that it accomplishes truly neat things.
The reverse (called a "dramatic failure", or a "botch" in the old WoD) also exists. If a dice pool is reduced to negative figures by penalties, the player can still roll a "chance die", where only a 10 counts as a success, and a 1 causes a "dramatic failure", which is just as good as it sounds. Some characters also have penalties where they can't use the "10-again" rule on certain rolls, and further lose successes on rolling a 1, which can result in them having negative successes, and thus get a dramatic failure.
Other Whitewolf games such as Exalted and Scion have the rule that a 10 is two successes and the more successes you get (often a certain number, such as your opponent's total successes) the better the result.
The Savage Worlds system has a similar mechanic, where rolling the highest number on a die lets you reroll it and add, and every multiple of four over the difficulty you are makes the result better.
Battletech has a system of critical hits that applies during a variety of situations. The most common being that after the external armor in a location has been eliminated, every successful attack made to its internal structure has a chance to critically hit and disable components and/or weapons placed there (anything from knocking out the small laser you weren't using anyway to penetrating the cockpit and killing the pilot on a lucky headshot) or even touch off an ammo bin resulting in predictably spectacular fireworks. (Modern units can have CASE — anti-blast magazines by any other name — installed to mitigate the damage to an extent; for anything without, it's usually a One-Hit Kill.)
Also, a 'Mech's head is generally its weakest spot. A big enough gun (like a Gauss rifle, which also doubles as one of the longest-range weapons in the game) can amputate it in one shot regardless of the target's weight class because heads are "one size fits all", and even lesser, non-penetrating hits will hurt and potentially knock out (or sometimes even kill) the pilot. This doesn't quite fall under the Boom, Headshot trope because the game goes out of its way to make actually aiming at the head hard at the best of times and flat-out impossible at others — but it can still come up as a random result on the hit location table.
In Nomine, which is based on the War between Heaven and Hell, has a special take on critical successes, not just on rolls involving fighting but on any roll (and critical failures) the game uses a system of rolling 3 six sided dice, a natural roll of 3 ones (representing the Holy Trinity) is a "Divine Intervention" which is good for angels and those allied with them, and bad for demons and their allies, a natural roll of 3 sixes (representing...well, you know) is an "Infernal Intervention" which is good for those on Hell's side and bad for those fighting for Heaven. Depending on the nature and circumstances of the roll, these Interventions can be anything from a(n) (un)lucky coincidence to a blatant spectacular manifestation of divine or infernal power.
Much like In Nomine, GURPS sets natural 3s a critical success. The effects are somewhat loosely defined except in certain cases.
4th edition upped the ante by having a natural 3 or 4 (and, with a high enough skill level, 5 or 6) count as critical successes. (Rolling three six-sided dice and getting a 3 has only a 1/216 chance of occurring, so the improvement to up to a 9% chance was welcome.) Conversely, a natural 18 or 17, or any roll that's 10 or more greater than your skill level, is a critical failure.
In combat, the most likely result of a critical hit is a blow doing ordinary damage. Editors have noted that this is realistic, since under many circumstances, a person might be lucky to get a hit *at all*, never mind do extra damage with it.
In Eclipse Phase, a 00 (rolling two ten-sided dice) is always a critical success. Any successful rolls that are doubles are also critical successes. Conversely, doubles on a failed roll is a critical failure, and 99 is always a critical failure.
Unknown Armies had perhaps the least forgiving critical hits in existence. A roll of doubles on the one-hundred sided die did damage equal to the roll - and could backfire if you missed. A roll of 01 meant the attacker chose to either instantly kill or instantly KO the defender. A roll of 00 let the defender return the favor.
New Horizon lists a one on the black die as an instant success, to be measured by the level of the white die.
Mutants & Masterminds has some brilliant critical rules. The "Natural 20 = Critical rule" also works outside combat. In a normal skill check, you figure out the degree of success as normal and then add another degree on top of it.
In combat, a 20 is an automatic hit, but you have to check if your characters attack bonus exceeds the target's defense before calling it a critical; which lets you either make the roll to resist much stronger, add an extra effect that's dealt at the same time (which requires a separate roll to resist, but sets the effect to rank 0, which means it's usually about 50/50 to resist for most), or to replace the attack with an alternate effect (Like swinging a sword and hitting a vein or artery. And you can set the rank for the effect.)
In Paranoia, depending on the GM, sometimes rolling a 1 is a Critical Hit; sometimes it's an Excessively Critical Hit (e.g. you blast the Commie through a wall, busting a pipe and flooding the corridor with sewage, then get fined for damaging valuable Computer property).
Ninja Burger, a card game of ninjas who deliver fast food to insanely improbable locations, has a mechanic where you test skills to complete your delivery. Rolling a 3 or 4 on three six-sided dice means the ninja did something so awesome, they gain one Honor (the game's Victory Points) just for that. In a game which starts players with six Honor each and ends typically when the average Honor reaches ten or four, this is a considerable bonus. And Combat is a skill every ninja possesses.
In the Growlanser series, characters can learn skills that increase critical rate and some techniques that are guaranteed to do extra damage.
The original Dragon Quest has criticals ("A terrific blow!"), just to show how long this has been in console RPGs. It is very useful for when fighting a Metal Slime, because a Critical Hit works by ignoring the enemy defense. The usefulness of such an attack against a Metal Slime, with its insane defense but low hit points, is obvious. However, critical hits in this game could in fact still miss: "Excellent move! It is dodging!"
In this game, critical hits were basically the only way to kill the last boss (absent a heroic level grind), since they ignore defense and the Dragonlord has obscene amounts of defense, turning it into a Luck-Based Mission for all but the grinding-est of level grinders. At level 30 he's a joke.
Dragon Quest II has critical hits for the player characters, in which they ignore defense and do double the usual damage. Ordinarily, enemies cannot land criticals, but a few late-game enemies can. These enemies also happen to have amazing attack power, leading to an easy One-Hit Kill on anyone without a massive HP total.
In addition, ever since the inclusion of "jobs" to the Dragon Quest series, there's always been a skill that allows a character to either land a critical hit or miss entirely every round.
Dragon Quest IX does this with both dodged and blocked attacks: "Critical Hit! (enemy) smoothly dodged the attack."
A couple of characters in the series can do EVEN MORE damage on a 'Trip and fall on the enemy' critical.
At least in some of the later games, there are enemies that can get critical hits too, which the game refers to as "desperate attacks". Depending on how strong your party is, and the strength of the enemy, a desperate attack could leave you at death's door. Your best bet is to keep your party fully healed and try to disable any monsters that you know are capable of desperate attacks. Dragon Quest Monsters: Joker features a skill, Critical Miss, which prevents the target from dealing critical hits.
In later games, spells can also "go haywire", which is the same thing.
Some items and skills have in their description that they can "cause a critical hit". It does not mean that their damage can be increased like in a normal critical hit, but rather that they have a chance to cause a One-Hit Kill.
Besides 1.5x damage (or 2.25x with the ability Sniper), critical hits also ignore stat changes if applying them would result in less damage (except in Generation I, where they ignored them either way). Any given move that does non-fixed damage has a 1/16 chance, which can be increased by various things on a "level" system from level 1 (regular) to level 4 (100%). Such are the power of critical hits that many battles are won and lost because of them. Examples of ways to raise said chances:
Holding either a Razor Claw or a Scope Lens raises the level by one.
Using the move Focus Energy or the item Dire Hit raises the level by 2 until you switch. (This is what "Foe Machop's getting pumped!" actually means.) Consuming a Lansat Berry gives the same effect, but they do not stack on each other.
Certain moves (including, but not limited to, Psycho Cut, Night Slash, Stone Edge, Cross Chop, and Cross Poison) have a ratio one level higher than normal attacks when used.
The ability Super Luck adds one level.
The Lucky Punch adds two levels to Chansey, while the Stick adds two levels to Farfetch'd.
Generation V introduced two moves, Storm Throw and Frost Breath, which have low power (60) but always get critical hits, making them effective wall-breakers.
Conversely, two abilities (Battle Armor and Shell Armor) and the move Lucky Chant avert the chance of the opponent landing a critical hit, making the above two moves far less useful.
Critical hits use to deal double damage (Sniper made it triple).
There were six levels of critical hit chance. Levels 1 and 2 were the same, but level 6 only had a 56.25% chance at most. Achieving level 6 was highly, highly situational, but still possible.
The above move-based examples apply to most Pokémon games, but Generation I (that is, Red/Blue/Yellow) works quite differently:
Each Pokémon has a different crit-hit chance proportional to its base Speed; thus a faster Pokémon is also more likely to go critical with any move. The highest chance (27.3%, better than 1 in 4!) belongs to Electrode, the fastest 'mon in the original games. The lowest, 2.9%, belongs to — who else? — Slowpoke.
The often-critical moves, most notably Slash, multiply those odds by 8. Yep, that means a fast Pokémon is guaranteed critical hits with those moves... unless the famous 99.6% bug crops up, that is.
Most bizarre, Focus Energy and Dire Hit are supposed to multiply the crit-ratio by four... but somebody in coding screwed up, so they divide it by four instead. Once you know this, it's fun to watch your opponent's Pokémon screw themselves over. (Stadium and all later games fixed the bug.)
These are made especially useful in the Pokémon Rumble series, as any Pokemon who becomes a victim of one will be stunned temporarily and defeating them during this time guarantees that you'll obtain them as an ally.
While not a damaging version, Generation V also added critical captures in which after one shake of the Poké Ball, the Pokémon is caught. This occurrence is marked by a sharp sound effect as the Poké Ball flies, and the ball shaking once it captures the Pokémon but before it lands. As there's only one shake check instead of three, your new chance of capturing is the cubic root of the normal chance (which is higher because these are percentages; for instance a 1/8 chance becomes a 1/2 chance). The chance of a critical capture occurring is the normal chance of a capture multiplied by a factor that increases as you get more entries in your Pokédex (and as this factor is 0 when you have less than 30, it never happens before then).
MOTHER 1 is the origin of SMASH attacks for the MOTHER series. These critical hits ignore defense, and will cause approximately your Offense stat worth in unblockable damage. Needless to say, these attacks usually work better for your enemies, since you are typically much better armored than them and they get SMASH hits at around the same rate that you do. And there are a lot more of them than you.
The Casey Bat, borrowing from the poem "Casey at the Bat", either connects with a SMAAAASH!! hit, or misses entirely. Also borrowing from that classic tale, it misses a lot. It has the highest attack power of any weapon in the game, but it also misses 75% of the time, as opposed to around 6% for normal weapons.
Enemies can (rarely) hit your party with SMASH attacks as well. However, certain enemies (most notably the various types of mouse) have such high Guts that they will land critical hits more often than regular hits. Since your defense stat is negated by these attacks, these enemies easily become Demonic Spiders; they can often do more damage than some party members' maximum health.
Perfect World does this with a twist. Any character's critical hit rate starts out at 1% of the time. Adding points to the Dexterity stat increases, among other things, your critical hit rate at about 1% every 20 points. Archers, who generally need huge amounts of Dexterity to function, get critical hits annoyinglyoften, and are not very fun to meet while PvP mode is on.
The Fallout games play this one straight and provide 'Perks' which may affect the chance of it happening or how much damage is done.
And if you get the "Sniper" perk and have 10 Luck (the maximum), every shot you fire is a critical hit. (The same is true of "Slayer" and melee or unarmed attacks.) At this point you can take out an entire military base with a BB gun (reload every 100 shots, can get five shots a turn with a few perks).
Also, the severity of each critical is determined at random. You can have several times normal damage, armor bypass, knockdown, knocking the target unconscious, status penalties... Meanwhile, it's entirely possible to have a lackluster critical hit, or appear to; if the person you're hitting has high damage resistance, it won't affect the critical hit's outcome. The Better Criticals perk increases the probability of a more severe critical (but not the chance of a critical happening) and is the only way for the Random Number God to roll above 100 on the critical hit table which results in an instant kill regardless of how much damage the attack actually dealt. Yes, it's possible to kill someone with a hit doing zero damage.
The combined Luck and Perk options really enable you to build a crit-heavy character For Massive Damage. Easiest to do with unarmed or small guns, a reliable crit-hitter has damage output that puts the Bozar to shame.
Scoring a hit on an enemy while hidden results in a Sneak Attack Critical for twice the normal Critical damage with ranged weapons, and 5x damage with melee weapons.
For Fallout 3 and New Vegas, the critical hit chance is solely determined by the equipped weapon, the luck stat, and any relevant perks (of which Finesse is probably the only one). However, the sneak attack critical does more damage than a regular critical, and it works every time so long as the target has not detected you. Combining high-powered weapons having (ordinarily) low crit chance with stealth can become a Game Breaker. Legate Lanius can be one-shotted with the right setup.
Golden Sun plays this one straight. Early on characters acknowledge critical hits for the most part as a power that occurs in battle without the user trying but being "there when they need it".
After a certain point in the game, most of the weapons found are magical (psynergical?) in nature, and have unique 'Unleash' abilities that activate randomly. Criticals and Unleashes are independent - you can miss your Unleash but still get a critical hit.
In Dark Dawn, there aren't any lucky attacks other than weapon unleashes, but many low-level weapons have an unleash named "critical hit".
The Final Fantasy games often play this one straight, although some have Action Commands. Sometimes, there will be weapons that always score critical hits, at the expense of some MP per swing (as such, those weapons are great for units that don't have a lot of magical strength, but still have MP)
Though interestingly, the "consume MP to inflict mortal blow" weapons in Final Fantasy VI don't work if the character doesn't have a Magic command (i.e. characters who can't use magic even with Espers, although this doesn't pop up very easily in normal gameplay), even though they can still have MP.
The Heroes of Might and Magic series use a Luck stat which determines a unit stack's chance to deal critical hits (or lucky hits). If it's negative, a feature of only a few games, the units may deal only half damage instead. This could get vicious with ranged units in melee, most of whom only deal half-damage anyway...
Some units also have special attacks that trigger randomly and may qualify as Critical Hits, but most of them aren't straight multipliers. One, such as the Dread Knight's death strike in III, is straight double damage...meaning quad damage if they're also lucky. Dread Knights being a high-level unit, such can get vicious. It's a good thing that, as undead, they can't be affected by morale and be allowed to attack again the same turn...
Fire Emblemlives by this trope. The series even has special animations for each unit when they do this. And they do obscene amounts of damage, thrice as much as normal. And from the third installment onward, they can't miss. (Of course, this is because crit checks are made after hit checks; attacks have to be able to connect before critical hits are even considered.) Here are some of the critical animations from the GBA games.
Except in The Genealogy Of The Holy War and Thracia 776. In those games, criticals double the user's attack stat before damage calculation instead. This actually means that criticals in Genealogy and Thracia are more powerful, unless you totally outclass your enemy (in which case he's going down anyway). Oh, and one family gets a skill that grants automatic criticals if the character is below 50% health.
Thracia 776 had a hidden stat that affect criticals dubbed the Pursuit Critical Coefficient (PCC), which is basically a crit chance multiplier (between x1 and x5) that is set for that character and can never be altered outside hacking. Also unlike any other installment, Thracia 776 had a critical hit chance cap of 25% for the unit's initial attack; any following strikes do not have that cap and will also factor the unit's PCC into the random number algorithms. That Swordmaster of yours with a 30% crit rate and a PCC of 3? Basically, his first attack only have a 25% chance of being a critical, but any and all extra attacks made after the opponent's(or that unit's second round of combat if the enemy attacked first) will have a whopping 90% chance of critting. This is why characters like Mareeta, Carion, and Fergus seem to have that nasty habit of getting crits on any of their sequential attacks.
Super Smash Bros. Brawl plays with this, giving Marth the Final Smash "Critical Hit" which does a ridiculous amount of damage (60%) and is the most likely attack to KO an opponent in one hit, aside from an attack used by the SNK Boss. When it hits, they even show a Fire Emblem health counter going from full to zero.
An offshoot of this is the Lethality/Silence skill that Assassins have, which is even less likely than a Critical Hit, which just kills the opponent regardless of how much more damage would be needed. The Assassin might only be able to do 1 natural damage per hit, but if they pull this out the enemy even at full health just drops.
In some games every class has a mastery skill based on other stats than luck that mimics this (note: these games still have critical hits based on the luck-stat, so you have TWO obscene luck based attacks), which will generally include beyond just increased damage regaining an equal count of health, eliminating the opponent's Defensive stats, paralyzing them (if they survive) or attacking multiple times. And the best mix of all this is Ike, AKA He Who Fights For His Friends, in Path of Radiance and Radiant Dawn, his Aether skill does two consecutive strikes, one healing him equal to the damage and the other eliminating defensive stats. Due to his own stats this is generally ten new kinds of overkill.
With Ragnell and Aether, Ike can pretty much solo the rest of the game and the bonus maps, although the final boss is still troublesome.
The most lethal of them all is the Black Knight's mastery skill in Radiant Dawn, Eclipse: it does quintuple damage and negates defense, so if he's wielding Alondite, he does a grand total of 280 damage. NO character in the series, player character, final boss, or otherwise, has more than 120 HP. Hell, roughly 90% of those characters won't even break 45 HP normally.
Swordmasters and Berserkers are designed to score lots of criticals. With the right kind of weapons they can raise this ability even further.
In Minecraft, a critical hit can be achieved by jumping and/or sprinting.
Terraria also has critical hits which the chance can be boosted by reforged items/weapons, buff potions, armor and armor bonuses, etc. The strikes are highlighted by a larger and deeper orange damage number that floats above the hit target for longer. If done correctly, it's possible to hit a target for triple digit damage.
Chrono Trigger. They're tied to the weapons; most have a 10% chance, although Frog's tend to be closer to 25%, but Crono's Infinity+1 Sword has a 70% chance. And Ayla will start doing 9999 damage on her criticals when she nears the end of the level cap (and her regular attacks aren't doing enough to justify that). Bear in mind that, with maximum levels and equipment, most characters' standard attacks deal in the neighborhood of 500-700 damage.
In the DS version, Robo has a weapon that works like a max level Ayla's, except that it has an attack power of zero, so its damage is well below average when it doesn't hit a critical. Crono gets an Infinity Plus Two Sword that has a 90% chance. Finally, there's the Dragon's Tear, which raises critical ratio like the Hero's Badge, except it works for any character and any weapon. Can we say "Murder In a Can"?
The game is also notable for having special animations and sound effects for crits. The ranged characters Lucca and Marle shoot extra projectiles; Crono, Frog, and Magus all do two-hit combos instead of doing a single hit; and Robo and Ayla attack downwards (while they normally hit sideways), and their hits emit more energy than they normally would. All of the crits are accompanied by the screen flashing, and somewhat altered sounds.
Chrono Cross, the sequel, tied this to the strength of attacks. From weak to fierce, the latter has higher chances of doing a critical hit, but has lower accuracy unless you chain it from other attacks. Also, while Serge's Infinity+1 Sword doesn't have the highest attack rating, its chances of doing a critical hit the ceiling to the point that even weak attacks do criticals.
The Mario & Luigi games, confusingly, use the word "Critical" to denote a hit that is elementally effective, but also have real critical hits as well, calling them "Lucky".
In Knights of the Old Republic there is actually a feat the player can learn called "critical strike". In this scenario however, the feat may temporarily paralyse the enemy rather than do more damage.
Since the KOTOR games are based off the DnD dice system, there is a critical hit range for each weapon. If the game rolls within a certain range on an attack, the damage is increased (Power Attack feats also make this increase larger). It is also possible to upgrade weapons with Massive Criticals - added damage upon critical hits. Abusing this system can make the game obscenely easy, since you're essentially able to make a One Hit Kill anything.
The Critical Strike attack also increases the chances of getting an ordinary critical- most weapons have a 5% chance on every attack (some have 10%), but with Master Critical Strike you can have 50% chance. Critical hits cause double damage.
Also worth noting here that you generally have a 50% chance of hitting at all. With Master Critical Strike and a high crit range weapon, every hit that you land is a crit. This tends to make people die.
City of Heroes has an interesting critical system, as each archetype has a different means of landing criticals. Scrappers have a set chance with every attack, with higher chances against higher-ranked enemies. Controllers have a chance to overpower an enemy while held. Stalkers (and Arachnos Soldiers) land free crits from Stealth, and can perform powerful attacks that can one hit kill most mooks. Dominators can activate a supermode to make every control power a crit for a brief period. Corruptors have a chance to land criticals any time the target is below 50% health, with the chance increasing as the target weakens.
Stalkers also have an interesting property in that each teammate nearby increases their chance of dealing critical damage. Apparently your chances of doing something impressive go up when there are more players to witness it, though the explanation is that the other players are distracting the enemies enough for you to do your thing more often.
The Magic Knight Rayearth RPG for the SNES had two levels of critical - a "Crushing attack!" for 2x damage and a "Greatest attack!" for 3x. It was quite amusing when cannon fodder enemies pulled these off for a whopping 3HP damage.
The First-Person ShooterTeam Fortress 2 has a random chance of critical hits with your weapon. Crits can be identified by their electrical sounds accompanied by glowing bullets, sparkling projectiles, or (in the case of melee attacks) unique swinging animations. The chance of getting a crit is increased by rapidly doing damage, which as you can imagine can become an upward spiral. This was specifically programmed by the developers to lessen the propensity of players to aim for the head and just shoot, reducing the overall skill required for the game.
However, headshots from sniper rifles and back stabs from a Spy automatically crit and are almost always instant kills.
Melee weapons are also far more likely to get Critical Hits. Depending on how much damage you've done in the last 20 seconds, ranged weapons have a crit rate between 2% and 12% (formerly 20%). Melee weapons started at 15% and max out at a whopping 65%. When you take into account that a single melee crit will give you 1/4 of that damage cap, you will hit the cap very, very quickly.
A particularly devastating weapon when it comes to crits is the Soldier's rocket launcher, since its base damage is held in check by getting less extra damage from close-range use, while crits still do triple base damage at all ranges. The fan nickname for such an instance is "crocket", a portmanteau of "crit" and "rocket". Killing three players with one earns the Soldier an achievement. The only class that can withstand a direct hit from a crocket from a stock bazoooka (while not overhealed) is the Heavy, and surviving a crocket grants the player an achievement as well.
Much like Dungeons and Dragons, buildings are completely immune to all critical hits and mini-crits.
Finally, capturing the flag grants the capturing team 8 seconds of critical hits.
There are some servers that make ALL attacks Crits; even weapons that don't deal random Crits will always deal them. This essentially makes almost all the characters save the Heavy/Soldier Glass Cannons.
The Medic has a secondary weapon called the Kritzkrieg that grants his healing target guaranteed critical hits for 8 seconds when it's fully charged.
A lot of weapons actually have conditional crits that can be activated in the right circumstances. Just to name a few, the Axengiusher will deal a crit against any burning player, the Flying Guilitine will crit any stunned player, and the Jarate will cover the enemy with "Liquid based Karate," causing the enemy to receive mini-crits instead of normal damage.
In Mann Vs. Machine, some of the robots are perpetually crit-boosted and any bomb carrier is once they hold the bomb for so long. To make up for this, one of cheapest upgrades you can get includes reducing the damage from crits. Humorously, at its highest level (three) the crit-boosting will significantly reduce damagenote Depending on distance a crit for most weapons does between 2 and 6 times normal damage and max resistance reduces damage from crits by 90%, so most attacks will do between 20% and 60% of the damage they would normally do.
The only weapon of the game that cannot be crit boosted in ANY WAY WHATSOEVER (Mods, 100% Crit Server, anything really) is the Cow Mangler 5000, a primary weapon for the Soldier.
The mecha-anime inspired FPS Shogo featured critical hits, and landing one restored a bit of your character's health. This was important since the game was particularly unforgiving about getting hit by any attack.
The Real-Time Strategy game Warcraft 3 had a critical hit mechanic. This was an ability restricted to certain units—a few Heroes could get it as as normal ability, while other heroes could find items to give them bonuses.
The Warlords BattlecryReal-Time Strategy series use a critical hit table that's based on the difference in Combat skill between the attacker and attacked. The special effect this had depended on the attack type.
Castlevania: Symphony of the Night stole many RPG statistical features. Critical Hits were a part of this and rates of making them were tied to each weapon.
Zone of the Enders: The Fist of Mars used a targeting-based combat system, but each enemy had one or more red circles on their body that, if hit by the center of the reticule, conferred a critical hit.
The story-mode only hero Kenji of Battle Realms has the Battle Gear Critical Strike which does a great amount of damage at the cost of some stamina.
Werewolves of the Wolf Clan also has a Wolf Bite Battle Gear, which acts as a critical strike, and can convert enemies into regular, tamable wolves.
Ditto for Brawlers, who have Zen Counter Punch that only works on heroes.
When Shingo Yabuki first showed up in The King of Fighters, he was a Joke Character with one benefit - his attacks randomly dealt a lot more damage and knocked the enemy a far distance back. The game showed the words "Critical Hit" when this happened. By KOF XI, Shingo had gained more power to balance him with the rest of the cast, so this ability went away.
World of Warcraftloves critical hits. Every class in the game has talents that provide further benefits from them occurring or at least increase they potency, while others get guaranteed Critical Hits under certain circumstances. You can increase your chance to get criticals of any kind based on stats granted by your equipment. There's even a chance for healing spells to have a critical effect. And for that matter, an increasingly large number of periodic damage spells can crit. You can poison someone, and the poison currently running through their veins will sometimes and somehow score a critical hit.
As well, physical attacks do double damage with a critical hit, while magical and elemental attacks do 150% (not quite as much, but still powerful since those go through armor and hit harder anyways). Death Knights, however, have a passive ability that lets their diseases and magical-type attacks do double damage with a critical hit.
Fire mages make critical hits such a common occurrence that there's a (useful) talent that only activates when you get two in a row.
Blizzard policy is that the chance of a critical should not, except where cooldowns or short-term talent effects are involved, ever reach 50%. Since if it did, there would no longer be a critical hit system in place. There would just be critical failures.
Super Smash Bros. also had one even before Marth got his aptly named Final Smash: Mr. Game&Watch has a move where he whacks the target while holding up a number ranging from 1 to 9. The damage and sideeffects vary, but the nine is a hard hitting attack that certainly qualifies as a Critical Hit.
Also, while not necessarily determined by luck (just good spacing), some characters' attacks are more powerful at particular points in their attacks' hitboxes (areas of effect for attacks). For instance, Marth's attacks are most powerful at the very tip of his blade; one well-placed forward smash can kill opponents as early as 50% or so, depending on the attack's position on the stage.
In Onimusha you have the chance to instantly kill the enemy by attacking at exactly the right time.
In Fatal Frame, you can snap weak photos of hostile ghosts at will. Letting the camera build up spiritual power yields stronger attacks, and waiting for the enemy to attack you first and then snapping them, mid-animation and at point-blank range, would yield the critical-hit Zero Shot.
Diablo II has both Critical and Deadly strikes. They serve the same "you do double damage" purpose, but come from difference sources- Critical Strike bonuses come from skills, while Deadly Strike bonuses come from items. However, success on one cancels the other (so there's no 4x damage). You can also get a chance of Crushing Blow from an item, which directly takes off a large percentage of the target's HP; gaining high crushing blow chances and a fast attack is how the Paladin "smiter" and Assassin's Kicksin archetypes function (they tend be a bit of Crippling Overspecialization, only worthwhile on bosses/duels).
Super Mario RPG features timed hits, which is a guaranteed critical hit as long as you press A again at the right time (usually upon the impact of the first hit) during an attack - when Mario's punch lands, when Mallow's cymbals come together, etc. Justified in most cases by adding an extra strike to the attack, making Mario punch more than once, for example.
Note that these aren't actual critical hits - the game does feature traditional critical hits, which may or may not overlap with this.
Crimson Gem Saga lampshades this by having a system that lets you actually continuing a critical hit into a series of follow up attacks. The result is that when you critical, you do it in a BIG way. To top this off, there is a character in the game that is devoted specifically for this purpose and has a 7 HIT CONSECUTIVE COMBO.
Likewise, Persona 3 and Persona 4's "One More" system give the character who landed the Critical Hit another free action. There are even spells (Rebellion and Revolution) that increased the probability of Critical Hits for everyone in the battlefield, which is useful against purely-magical foes who won't take advantage of them.
In Persona 3, each characacter has a condition with four possible states: Great, Good, Tired, and Sick, determined by how much a character spent time in Tartarus in the past few nights, as well as random factors for non-protagonist characters. Characters in Great condition have a higher chance of nailing critical hits (it's not uncommon to nail two or even three criticals in a row), while characters in Tired or Sick condition will be more likely to get whacked with critical hits. The Distress status effect can also increase one's suspectability to a critical.
A different mechanic is more of the random bonus variety, however; All elemental weapons have a chance of exploding in their element rather than just plain shooting. When this triggers it either starts the enemy taking continuous damage or does boosted damage for that one hit. Better guns do it more often.
Ys: The Ark of Napishtim and other 3D games in the series have luck-based critical attacks(which the enemies can also do on Nightmare difficulty), obtaining a certain item increases the frequency of these.
Some of the World of Mana games have critical hits which not only do more damage, but also ignore the enemy's defenses. This can be handy since enemies in this series are notoriously picky about what weapons will damage them. If you don't have the right weapon, your best chance to win is to keep attacking till you get a critical hit.
The MMORPGRagnarok Online features critical hits, but it makes you work for them. Unlike some MMOs, you select your stat increases on levelup. The game features a pile of useful stats, and a single barely-worthwhile LUK (luck) stat. The sole things this stat covers are critical hit chances, and "perfect dodge" (normal dodging can be overwhelmed by numbers, but LUK dodging is set). The problem is that you have to pump large amounts of LUK every level to get any appreciable crit rating. Further, these are points that are NOT spent on bread-and-butter damage stats. The only ones who can really get any use out of it are Assassins, who can equip crit-chance-doubling katars. For everyone else it's a controversial and generally weak stat, and even for Assassins, auto-attack-reliant "Crit Builds" have fallen out of favor given the absurd burst damage that player skills have
It should be noted that LUK builds are also fairly popular with hunters, who have falcon companions. The bird's signature attack is a multi-hit AoE strike called Blitz Beat, which can be activated by chance on a normal attack at a chance roughly equivalent to the crit rate. What this means is that a DEX-LUK Hunter, properly buffed for attack speed by allies and potions, can have a fairly high chance of each shot essentially doing six times the normal damage. That could itself be considered a Critical Hit.
There's also a somewhat popular LUK build for Knights, utilizing the Muramasa, a powerful two-handed sword that increases attack speed by 8% and crit rate by 30%, with the downside of a small chance of Cursing yourself. A Knight using this method would keep his LUK just above his level, preventing the Curse status from taking effect and further boosting his crit rate.
Every Wild AR Ms game uses critical hits in some way or another, but the fourth and fifth games take it further with Finest Arts. These require a Punching Glove or SheriffStar badge to be equipped and do significantly more damage than a critical hit. In 5, they replaced critical hits all together, and were still buffed by the main character's ability "Double Critical".
The Super Robot Wars series uses critical hits, they do either 1.2 or 1.5 times the damage depending on the game. There's also a spirit command in some of the games that makes every attack made by that unit a critical attack for one turn.
Disgaea: Hour of Darkness has its weapons have a fixed chance for criticals, with Axes having the highest natural chance (30%). Disgaea 2: Cursed Memories added the Professional specialist, which upped the critical hit chance proportional to its level (and it caps at 100), and the Item World's Item Assembly can up the critical hit chance. The Male Warrior dealt increased critical hit damage when at 25% health, and the Berserker unit in Disgaea 3: Absence of Justice can get an evility that gives him guaranteed Critical hits when he has an axe.
Disgaea 2 also has an unusual in-story example. Very early in the game, a Prinny sneaks up behind Rozalin while she's not paying attention, and drops a bomb on her. Adell cracks the fourth wall to mention that it's this trope.
Critical hits are essential to Warriors and Rogues' special attacks in Dragon Age: Origins, since many special effects (like stun, knock-down, bleeding, etc.) are only triggered if the special attack lands a critical hit. It is counter-balanced by armor penetration, since weapons that have high probability of a crit (swords and daggers) have low armor penetration and vice versa (axes and warhammers).
As a nice touch, a critical hit on a frozen solid non-boss enemy will shatter said enemy. No matter what his/her/its health level, that is an instant kill and an excellent way to improve your odds when a large group attacks.
In Master of Orion II there's a chance (enhanced with a special targetting system) of hitting a ship's weapons and other systems after Deflector Shields and armor don't stand on the way. A ship with broken computer can't hit a planet one square away, with broken drive it loses mobility: at half of drive's Hit Points the ship is a sitting duck and can be boarded, at 0 it explodes no matter how much armor and hull Hit Points remains. This means artillery in Armor-Piercing Attack variant is devastating, as few shots can cripple or destroy a ship the moment its shield is down... unless it has bulky Heavy Armor upgrade.
In Shining Force, there are three damage modifiers: the enemy evades the attack, the chance for a second attack, and the Critical Hit. Critical hits give off a special sound and are not evaded (otherwise how would you tell?). They also increase the damage from attacks, generally anywhere between 1.5 and 2.0 times the damage. As it's independent from the chance for a second attack, rare luck could result in 4 times the damage. As it is damage and not attack power, an attack that only inflicts Scratch Damage will still only inflict 1 HP of damage. This is a useful for the first game's Lightning BruiserMeatShield, Domingo, who attracts a lot of attacks due to being a magician.
To clarify: When you hit an enemy they take damage to where you hit them. So if you slice off their arm, they will be weaker, but it doesn't do a set amount of "hit point" damage. Attacks to critical areas like the neck, heart, lungs, and brain will kill the enemy becasue they can no longer function. But they can still die other ways, such as bleeding or falling a long drop.
Happens on occasion in Rockman 4 Minus Infinity. Get the Super Star from any Shadow Man encounter by finishing him off with a Recycle Inhaler, and the chances of this increases. His final appearance, unlocked by doing a No Damage Run up through Wily 4, drops the ?Dagger, which makes every hit critical.
In The Order of the Stick, a natural 20 was actually a prophesy, for when Roy was to know to take a shot at a moment when such a roll was needed most.
In a joke in this webcomic, which the author plans to reuse in the reboot, a character rolls a natural 20, but it's for initiative, and is pissed there's no such thing as critical initiative. Made funnier by the fact that some games do have critical initiative (picking when you go instead of going first).
Spoofed in the webcomic Commissioned, the main characters have DnD sessions where it switches from the POV of their characters to them, and occasionally they try something completely off the wall... and end up rolling a natural 20. this comic is a more recent example even though it's actually a bluff check.
In D&DS9, The Borg's attack on the U.S.S. Saratoga is a critical hit, but the DM fails to notice. That is, until Avery (Sisko's player) points it out to him. It doesn't end well.
In NeoQuest II you can only get this by using level points to upgrade Critical Hit levels, and only Rohane can use it.
Sometimes really easy to do to a person in general. The body usually doesn't know what to do when a chunk of metal (be it a blade, bullet, or arrow) enters it violently, so it tends to just spasm, fall down, and stop working properly. The resulting debilitation can be deadly later on, when bleeding out or dying from infection.
It is in fact quite possible to outright kill a person with a firm blow to the chest, so long as it is done at exactly the right time. The phenomenon known as commotio cordis occurs when a person is hit in the chest during the most sensitive part of the heartbeat cycle; this can disrupt the heart and cause fibrillation. It often happens in sports as a result of being hit by a ball, and has a rather grim survival rate of 35%.
Grappling injuries. There are plenty of times when, simply as a consequence of landing at a bad angle or being tripped at precisely the wrong moment, you get a sprained ankle, a busted knee, a dislocated shoulder, etc., etc. As any victim of this can tell you, when you get one of these, the match is over and you have lost, PERIOD. This is true even if the throw was not technically successful. That happens quite a lot.
Proper training in landing techniques can help to (significantly) lower the odds (and this is what most of the training in Professional Wrestling really is), but it only goes so far.
In his book Have a Nice Day: A Tale of Blood and Sweatsocks, professional wrestlerMick Foley talks about all his injuries. This is a guy who has been cut, burned, blown up, and had pieces of him removed with ropes. Yet he says the worst injury he ever had was a pinched nerve that caused so much pain it was hard to move.
Boxing. Joe Louis Vs. Max Schmeling both parts might qualify. In part one, Schmeling specifically said in interviews that he aimed for a spot where he knew Joe Louis would drop his guard. He apparently learned about it from watching recorded fight films. Once that one punch was landed, experts say the fight was over.
In their rematch, Max Schmeling claimed that he turned the wrong way and instead of taking a body blow where he was trained to, he took a kidney blow. He said after the fight that his entire side went numb.
In an MMA fight chronicled by Seanbaby in a Cracked article, similar to the above, one fighter took a body blow in exactly the wrong place - in this case, his liver. Before the crippling pain and unconsciousness took him, he threw one final, wild punch... and knocked the other guy out cold,winning the match.
Dental work is much less painful nowadays than it used to be, but there are still... quirks. Usually, when your dentist injects your gum with freezing solution, it only hurts a little. But there's a very small chance that the needle will pinch a nerve — and that hurts like you would not believe. (Don't tell Miyuki.)
The Code Duello specifies that any injury that prevents a combatant from holding a weapon steady ends the duel automatically.
Happened not once but twice in the hunt for the Bismarck: once when the Bismarck scored a one-in-a-thousand hit on the HMS Hoodright in the magazine and blew her in half, and once again when a last-ditch flight of Swordfish torpedo bombers managed an equally improbable shot into the Bismarck's rudder. That crippled the Bismarck and left her at the mercy of the entire British fleet. Had either of the events not transpired the way they did, the chase could have turned out wildly different.
Similarly, during the Japanese attack on Pearl Harbor, the battleship Arizona took an armor piercing bomb to the magazine. Over a thousand crew died in the resulting explosion, which was caught on film and is used as Stock Footage whenever America's entry into World War II is mentioned. Warships' magazines tend to be very heavily armored and deep inside the ship, making it very unlikely for them to take a hit. But when they do take a hit...
Repeated in the WWII sinking of the Yamato, Japan's super battleship that was disabled with a lucky torpedo blow to the screws.
I believe that is the German battleship Bismarck you are thinking of. The Bismarck previously curb-stomped British flagship, the Battlecruiser HMS Hood. (See Above) The Yamato by contrast succumbed after enduring multiple waves of US Navy dive-bombers and torpedo bombers during Operation Ten-Go. The torpedo bombers intentionally focused nearly all of their attacks on the port side to cause rapid flooding with the goal of causing the ship to capsize. It worked. In the end Yamato endured so much punishment before going down, it may be more akin to a Critical Existence Failure or perhaps a Rasputinian Death
This is pretty much standard for most armored vehicles, on air, land, or sea. General blows around the armor plating tend to either bounce off, or cause little real damage, but a single hit (lucky or aimed) to a vulnerable section like the fuel tank or stored ammo tend to be very debilitating, very quickly. Mobility kills by hitting a soft spot required for locomotion are also good, but not nearly as spectacular.
The USS Johnston pulled off one of these during the Battle Off Samar. The Johnston hit the Japanese Heavy Cruiser Kumano blowing off the entire bow. The Japanese ship survived the battle.