History Sandbox / RandomCriticalHit

* ''TabletopGame/DungeonsAndDragons'' has random crits determined by the dice roll of the attack. The specifics vary from edition to edition, but the most famous incarnation is the UsefulNotes/D20System's "natural 20" (getting a result of 20 on the 20-sided die, before adding any modifiers), though it's possible to increase this (ie, a crit on a 19 and up, or 18 and up, or 17 and up...) with certain items, spells, or abilities. Some games using the system (such as ''TabletopGame/MutantsAndMasterminds'') also use critical successes on ''anything'' that involves rolling a [=d20=] (which, in the d20 system, is virtually everything) rather than only on attacks.

* Any game based on ''TabletopGame/DungeonsAndDragons'' or the UsefulNotes/D20System, such as the ''VideoGame/BaldursGate'' and ''VideoGame/KnightsOfTheOldRepublic'' series, generally uses critical hits in the same manner as their tabletop counterpart.

* ''VideoGame/{{Ys}}: The Ark of Napishtim'' and other 3D games in the series have [[LuckStat luck-based]] critical attacks.

* ''Franchise/{{Ys}}: The Ark of Napishtim'' and other 3D games in the series have [[LuckStat luck-based]] critical attacks.

* ''VideoGame/PerfectWorld'' has a crit rate is based on Dexterity, so classes that use a lot of Dexterity anyway (like [[GlassCannon Archers]]) get crits at GameBreaker rates. This is exceedingly annoying in PvP.

* ''TabletopGame/DungeonsAndDragons'' has random crits determined by the dice roll of the attack. The specifics vary from edition to edition, but the most famous incarnation is the TabletopGame/D20System's "natural 20" (getting a result of 20 on the 20-sided die, before adding any modifiers), though it's possible to increase this (ie, a crit on a 19 and up, or 18 and up, or 17 and up...) with certain items, spells, or abilities. Some games using the system (such as ''TabletopGame/MutantsAndMasterminds'') also use critical successes on ''anything'' that involves rolling a [=d20=] (which, in the d20 system, is virtually everything) rather than only on attacks.

* Any game based on ''TabletopGame/DungeonsAndDragons'' or the D20System, such as the ''VideoGame/BaldursGate'' and ''VideoGame/KnightsOfTheOldRepublic'' series, generally uses critical hits in the same manner as their tabletop counterpart.

* ''{{Rolemaster}}'' has its criticals be random twice over; you rolled your attack and consulting the weapon's table to see if your result was a crit, then you rolled on the crit table to see what the effect of the crit was.

* ''TabletopGame/{{Warhammer}} Fantasy Roleplay'' has the "Ulric's Fury!" rule, where rolling maximum damage and then succeeding on a weapon skill check allows you to roll damage again and add that to your total (and this continues until you fail the check or roll less than maximum damage). The ''Franchise/{{Warhammer 40000}}'' version, ''TabletopGame/DarkHeresy'', has the same thing (now called the "Righteous Fury!".

* Both the ''TabletopGame/{{Warhammer}}'' and ''TabletopGame/{{Warhammer 40000}}'' wargames themselves have critical hit mechanics that activate on rolling max damage.

* Present in the ''Franchise/{{Lufia}}'' series. In ''VideoGame/LufiaCurseOfTheSinistrals'', it's possible with Mystic Stones to raise a character's CRT stat to 100, which makes every single attack a critical hit.

!!Examples:

* ''Roleplay/DestroyTheGodmodder'': An attack has a random chance of critting, which is a 2x damage bonus. There's also mini-crits, which give a 1.5x bonus. Players tend to boost each others' attacks frequently, so expect a lot of these.

[[folder:Tabletop Games]]
* ''TabletopGame/DungeonsAndDragons''
** The best known is, of course, rolling a "natural 20"[[note]]that is, getting a result of 20 when rolling a 20-sided die, before any modifiers are applied[[/note]] in combat did bonus damage -- this started out as a common house rule which became an official option in the 2nd edition.
** The 3rd Edition allowed things besides attacks (like skill checks) to crit, and also made critical hits in combat more complicated. The initial roll wasn't an automatic crit, it was a "threat", which had to be "confirmed" with a second roll. If the threat fails to confirm, the attack is a normal hit, not a crit. Different weapons also had different crit rates; everything got a threat on a natural 20, but some weapons would get a threat on lower numbers as well (eg, rolling 19 ''or'' 20 is a threat). Some spells and abilities could increase this evne further, and some builds [[CriticalHitClass took advantage of this]], rolling threats virtually every time they attacked.
** 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, unlike earlier editions, has no creatures that were immune to 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, ''[[IncrediblyLamePun critical]]'' role in resolving a combat.
* ''TabletopGame/{{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 40K version, ''DarkHeresy'', has the same thing (only it's now called the "Righteous Fury!", and isn't nearly as fun to shout).
** ''TabletopGame/BlackCrusade'' replaced Righteous Fury with Zealous Hatred, which instead of making the damage die explosive, makes you roll a d5 on the critical damage table, independently from any other critical damage (the numbers don't stack). This makes BC's critical hits crippling blows rather than simply dealing additional damage.
* ''TabletopGame/{{Warhammer}}'' has a few of them itself: Irresistible Force, a critical success at casting a spell that means it can't be dispelled (contrast with [[CriticalFailure Miscasts]]); PoisonedWeapons 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 [[HeroicResolve holding out against impossible odds]].
** Now an official rule, in 8th Edition. Also, Irresistible Force now not only counts as a critical cast, but also a miscast -- it deals extra damage to the target, but also does damage to the attacker.
* ''TabletopGame/{{Warhammer 40000}}'' has a few units with similar rules. Rending most notably, and certain [[ClapYourHandsIfYouBelieve Acts of Faith]] used by the [[AmazonBrigade Sisters of Battle]]. Meanwhile the Gets Hot! rule represents CriticalFailure on a weapon.
** In one of the previous Chaos SpaceMarine codexes, the [[{{BFS}} 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 [[MightyGlacier Terminators]] being chopped down by one really pissed-off guy with an axe.
** Leadership tests in ''TabletopGame/{{Warhammer 40000}}'' (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. PsychicPowers 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 Ork tellyport blasta has both the "rending" rule and a rule that makes its wounds "instant death" ones when rolling 6.
* The ''TabletopGame/NewWorldOfDarkness'' 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.
** [[CriticalFailure The reverse]] (called a "[[EpicFail 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 ''TabletopGame/{{Exalted}}'' and ''TabletopGame/{{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 ''SavageWorlds'' 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.
* ''{{TabletopGame/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 OneHitKill.). Most components suffer a CriticalExistenceFailure upon a critical hit, even if they occupy multiple critical slots, but a few major components instead suffer penalties but still function (up to a limit of hits).
** Also, a 'Mech's head is generally its weakest spot. A big enough gun can amputate it in one shot regardless of the target's weight class because heads are "one size fits all" and rather thinly armored[[note]]It's not so much the "head" but the "cockpit canopy glass"[[/note]]. Such weapons that can reliably focus enough damage to take a mech head off in one shot are known as [[BoomHeadshot headchoppers]]. Even lesser, non-penetrating hits will hurt and potentially knock out (or sometimes even kill) the pilot. This doesn't quite fall under the BoomHeadshot 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.
* ''TabletopGame/InNomine'', 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, [[NumberOfTheBeast 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 [[DeusExMachina a blatant spectacular manifestation of divine or infernal power.]]
* Much like ''TabletopGame/InNomine'', ''TabletopGame/{{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 ''EclipsePhase'', 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.
* ''TabletopGame/UnknownArmies'' 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.
* ''NewHorizon'' lists a one on the [[ColorCodedForYourConvenience black die]] as an instant success, to be measured by the level of the white die.
* ''MutantsAndMasterminds'' 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.)

* ''NinjaBurger'', 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.
* The ''TabletopGame/DragonAge'' tabletop adaptation does not have regular critical hits, but instead features "stunts". Every attack roll is a 3d6 and one die is always colored differently from the other two: if any two of the three land with the same face up, the attacker can perform a stunt, such as dealing extra damage, cleaving into an adjacent enemy, knocking the target prone, pushing them away, etc. Stunts have different point costs and how many points a player can spend depends on the roll of the aforementioned differently colored die--it is even possible to string together several stunts on a particularly lucky roll.

[[folder:Video Games]]
* The ''VideoGame/DragonQuest'' series has several examples:
** ''VideoGame/DragonQuestI'' has random criticals ("A terrific blow!"), just to show how long this has been in console {{RPG}}s. Crits work by [[ArmorPiercingAttack ignoring the enemy's defense stat]], which means they're very useful for fighting enemies with relatively high defense for their HP, like {{Metal Slime}}s and the FinalBoss.
** ''VideoGame/DragonQuestII'' 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 OneHitKill on anyone without a massive HP total.
** ''VideoGame/DragonQuestIX'' does this with both dodged and ''[[LuckilyMyShieldWillProtectMe 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. ''VideoGame/DragonQuestMonsters: 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 OneHitKill.
* In the ''{{Growlanser}}'' series, characters get random crits, and can learn skills that increase their critical rate.
* Any game based on ''TabletopGame/DungeonsAndDragons'' or d20 rulesets, such as the ''BaldursGate'' and ''KnightsOfTheOldRepublic'' series. ''Knights of the Old Republic'' includes one of the more compelex systems: generally, vibroblades, single lightsabers, and rifles can score a critical on a 19; everything else requires a 20. A few weapon upgrades make a weapon "keen", doubling the critical range, and the Sniper Shot and Critical Strike lines of feats also increase the odds of a critical. In [[VideoGame/KnightsOfTheOldRepublicIITheSithLords the sequel]], each weapon type has an keen upgrade, and disruptor weapons can score a critical on ''18''. A disruptor with an Accuracy Scope fired using Master Sniper Shot can score a critical on a ''6.''
* In the ''Franchise/{{Pokemon}}'' games, any move that does non-fixed damage has a 1/16 chance to crit, dealing extra damage and ignoring any stat changes (such as your attack being lowered or your target's defense being raised) that would reduce damage[[note]]in Generation I, it would ignore stat changes even if they ''increased'' your damage[[/note]]. The base crit chance can be increased by various things on a "level" system (eg, level 1 is standard 1/16 chance, and each higher level makes a crit more likely). The exact details vary from generation to generation, but crits remain potent enough to be major game-changes regardless.
** Generation V also added critical captures, when you throw a pokeball. The chance of a critical capture is the normal chance of capture, multiplied by a factor that increases as you get more entries in your Pokédex. The capture chance of a crit capture is the cube root of the normal capture rate -- this increases the odds because capture rates are percentages (eg, a normal capture rate of 1/8 becomes a crit capture rate of 1/2).
* The ''VideoGame/{{MOTHER}}'' series has ''SMASH'' attacks, which are critical hits that ignore defense, and will cause approximately your Offense stat worth in unblockable damage. Each physical attack has a random chance of being a smash hit, with the rate determined by your Guts stat (higher Guts means more smash hits). Needless to say, these attacks usually work better for your ''enemies'', since they can get smash hits against you as well, and [[HealthDamageAsymmetry you tend to have high defense and low health, while they have high health and low defense]]. Not to mention that there are a lot more of them than you.

A random critical hit is a type of CriticalHit where the possibility of any given attack being a critical hit is random, rather than being determined by the player's actions. Often the chance of getting a crit can be influenced, through a LuckStat (or a stat that specifically affects the frequency of your critical hits), by using different weapons or abilities that have different critical hit rates, or via positioning attacking characters to take advantage of GeoEffects (or merely let them [[BackStab attack from behind]]). When random critical hits are in effect, though, none of these things will ''guarantee'' a crit -- even if you have a 90% chance of critting on any given attack, whether you ''actually'' crit or not is ultimately up to the RandomNumberGod.

Most common in TabletopGames and VideoGames where there's some element of randomness in whether your attacks hit at all. As with any randomness in game mechanics, random critical hits help make things more interesting by making events less predictable. A lucky crit can turn a losing battle into a hard-won victory -- and an ''un''lucky crit can turn an easy RandomEncounter into a scramble for survival (or a GameOver if you're ''really'' unlucky).

* One Example
* Two Example
* RedExample
* [[Creator/DrSeuss Blue Example]]