Critical Hit Critical Hits are hits which cause extra damage , or other side effects . If a hit is successful , it may become a critical hit if it passes Critical Chance . The effect of the hit is determined by another roll , on the critical hit table . For critical hits that are not aimed shots , the critical effect is based on the torso column while aimed shots can choose from the other part of the anatomy such as eyes , head , groin , pincers , servomotors , arms or legs . Each bodypart and each type of critter has its own set of possible critical hit effects . For example , living creatures with eyes tend to be particularly vulnerable to eye criticals , but other types of enemy are often more vulnerable elsewhere . The effect of a critical hit can be modified by the Perk Better Criticals . Note that the chance for a critical hit is determined by Critical Chance , and is not the same as critical effect . See Aimed Shot in the Combat section for more info . " Fallout " , " Fallout 2 " and " Fallout Tactics " . Critical effects . < section begin = " Effects " / > This is the critical hit table for human men . Tables for other critters are different , and can be found here . < section end = " Effects " / > The Basic Critical Damage Calculation Formula . Nearly all critical hits do extra damage . This happens through the addition of an extra Damage Modifier , which is added over and above any damage modifier that the weapon ' s ammunition might already have . For example , a critical hit from a Needler pistol loaded with HN AP Needler cartridge will have , firstly , a 2 / 1 modifier courtesy of the ammunition , plus another damage multiplier ( most typically 3 / 2 , 2 / 1 , or 3 / 1 ) determined by the critical effect roll . The same way as with non - critical hits , the damage output ( base damage * ( possible ammo damage modifier ) * critical damage modifier ) is calculated first and the damage reduction effected by the target ' s armor is calculated second . And as with non - critical hits , the target ' s ( natural or worn ) Damage Resistance ( DR ) is affected by the ammunition ' s possible Damage Resistance Modifier . Example . Mike is intercepted by leather - armored raiders on his way from Vault City to New Reno . He is armed with a Desert Eagle loaded with . 44 Magnum JHP . The weapon ' s base damage is 10 - 16 . He shoots the nearest raider in the eyes and scores a critical hit , rolling 12 base damage and 18 on the critical effect table : 2x damage and roll Luck with + 4 or get blinded . The ammunition has a damage modifier of 2 / 1 and the critical damage multiplier is 2 , so the damage output before armor effects is 12 * 2 * 2 = 48 . Leather armor has a Damage Threshold ( DT ) of 2 and a damage resistance ( DR ) of 25 % . The damage of 48 first undergoes a reduction of 2 , leaving 46 . Then the DR steps in . It is increased from 25 % to 45 % due to the ammunition ' s DR modifier of 20 . The damage of 46 thus undergoes a reduction of 46 * ( 25 % + 20 % ) = 20 . 7 ( round down ) = 20 . The raider ' s base Luck is 5 . The 4 - point Luck bonus gives him a 90 % chance of passing his Luck roll , which he does and thus keeps his eyesight . The raider takes 46 - 20 = 26 Hit Points of damage but keeps coming forward . The Armor - Piercing Effect . Though the combat message accompanying these critical hits reports the armor being " bypassed " , these criticals rarely bypass the target ' s armor in its entirety . An armor - piercing critical hit features the Weapon Penetrate effect combined with a DR modifier of 1 / 5 , thus dividing both DT and DR by 5 and ( where applicable ) rounding the result down . Weapons that already have the Weapon Penetrate perk do not gain an additional DT - reducing effect . If the weapon ' s ammunition has a DR modifier , positive or negative , it is factored in after the armor - piercing critical effect . This means that if the ammunition has a sufficiently negative DR modifier , an armor - piercing critical will negate 100 % of the target ' s DR . Conversely , if the ammunition ' s DR modifier is poor ( a big positive number ) , then DR will reduce a considerable percentage of even an " armor - piercing " critical hit ' s damage . The positive DR modifier caused by the perk Finesse is nullified by the armor - piercing critical effect . Example . Mike is intercepted by a squad of Enclave patrolmen on his way from San Francisco to Navarro . He is armed with an Assault rifle loaded with 5mm JHP . The weapon ' s base damage is 8 - 16 . Mike decides to take an aimed shot at the head of the peskiest patrolman because the distance is too long to burst effectively . He hits his target , rolling 13 base damage and 76 on the critical effect table : 2 . 5x damage , armor pierced , knockdown , roll EN with - 3 or get knocked out . 5mm JHP has a Damage Modifier of 2 / 1 and the critical damage modifier is 2 . 5 , so damage output before armor effects is 13 * 2 * 2 . 5 = 65 . The Advanced power armor worn by the enemy has DT 15 and DR 55 % . The armor - piercing effect of the critical hit first divides these by 5 , leaving 3 and 11 % , respectively . The damage of 65 undergoes a reduction of 3 , leaving 62 . Then DR steps in . 5mm JHP has a DR modifier of 35 , increasing the diminished DR back up to 11 % + 35 % = 46 % . Thus the remaining 62 points of damage undergo a reduction of 62 * ( 11 % + 35 % ) = 28 . 52 ( round down ) = 28 . The Enclave patrolman takes 62 - 28 = 34 HP of damage and is knocked off his feet . With his base Endurance of 8 and the penalty of - 3 , he has a 50 % chance of staying conscious . He fails this roll and blacks out for 3 turns . When he wakes up , Mike has killed his colleagues and stolen his weapon . Critical Burst Attacks . A burst attack is critical if its first round hits the intended target AND the attack passes its critical chance roll . Burst weapons often miss many more rounds than a 95 % chance to hit would warrant , even at point - blank range . Rounds that hit the wrong target ( or miss entirely ) never cause critical hits . When a burst attack is critical and rolls a critical effect , that same critical effect ( and damage multiplier ) is applied to every round that hits the intended target . However , each round makes an individual roll for hit / miss and base damage . Example . On his way back to San Fran from Navarro , Vertibird plans in his pocket , Mike is intercepted by a pack of Deathclaws . The nearest animal , a Sm tough deathclaw , charges Mike forthwith and claws him for 10 HP before he can react . Mike is now armed with an H & K G11E and decides that the point - blank range warrants a burst attack . The weapon ' s base damage is 13 - 23 . By a lucky break , he scores a critical hit and rolls 95 on the critical effect table . On a deathclaw , the effect is 2 . 5x damage , armor pierced , knockdown . The 4 . 7mm ammo used by the weapon has a damage multiplier of 3 / 2 and a DR modifier of - 10 . The deathclaw ' s thick skin endows it with 4 DT and 40 % DR . The first bullet of the 7 - round burst rolls 15 base damage . This is multiplied by 3 / 2 , yielding 22 . 5 , which is not yet rounded at this intermediate stage but multiplied by the critical damage modifier of 2 . 5 , yielding 56 . 25 . This is rounded down to 56 . The armor - piercing critical effect divides the deathclaw ' s DT of 4 by 5 , yielding 0 . 8 ( round down ) = 0 . Its DR of 40 % is likewise divided by 5 , yielding 8 % , which is then further reduced by the ammunition ' s DR modifier : 8 % - 10 % = < 0 % . Thus , this is a case where the armor - piercing critical effect and the ammunition ' s favorable DR modifier combine to negate the target ' s armor completely - - all 56 points of damage go through . Bullet 2 : 17 * 3 / 2 * 2 . 5 = 63 . 75 = 63 Bullet 3 : 13 * 3 / 2 * 2 . 5 = 48 . 75 = 48 Bullet 4 : 14 * 3 / 2 * 2 . 5 = 52 . 5 = 52 Bullet 5 : miss Bullet 6 : 21 * 3 / 2 * 2 . 5 = 78 . 75 = 78 Bullet 7 : 18 * 3 / 2 * 2 . 5 = 67 . 5 = 67 The deathclaw takes 56 + 63 + 48 + 52 + 78 + 67 = 364 HP of damage and is torn to gory shreds . Mike continues towards San Fran on his quest . Notes . The only way to roll a 101 or more is to take the Better Criticals perk . In " Fallout 3 " and " " , many energy weapons incinerate or liquefy targets on a deadly critical hit , turning them into permanent ash or goo piles that will refill with loot every time the creature would normally respawn . These can be useful for farming items or permanently clearing out infested areas like the " El Dorado Dry Lake " without losing the items obtained by hunting the NPCs . " Fallout 3 " and " Fallout : New Vegas " . In " Fallout 3 " and " " , the critical hit feature is simplified from " Fallout " and " Fallout 2 " . When a weapon is fired , it has a predefined , specific percentage chance of getting a critical hit ( with a few exceptions , see below ) , which is essentially just added damage to the original base damage ( the damage that will be dealt if the PC does " not " score a critical hit ) . This obviously sounds much simpler than the system of the first two games , but it is still more complex than it sounds . Critical Chance . The player ' s base Critical Chance is determined by the Luck SPECIAL statistic and the Finesse , Survival Expert , and Ninja perks . The maximum possible base critical Chance is 18 % with ranged weapons , and 33 % with unarmed and melee weapons . The base Critical Chance is modified by a weapon ' s critical multiplier to obtain the final chance to score a critical hit . Also , a + 15 % Critical Chance bonus ( + 5 % in New Vegas ) is added to all attacks in V . A . T . S . Critical Damage . Every weapon has a predefined critical damage , which is the damage added during a critical hit . The only modifier to critical damage is the Better Criticals perk , which gives criticals a 50 % damage bonus . This is a lot more impressive than it sounds . For example , the Wazer Wifle has a critical damage of 28 , but with the perk , the critical damage becomes 42 , making 70 damage on a non - sneak critical and 140 damage on a Sneak Attack Critical . Sneak Attack Critical . A Sneak Attack Critical occurs when successfully attacking an opponent while being by using one ' s Sneak skill . Successfully hitting the target will result in a guaranteed critical strike . This more specialized critical strike " doubles " the damage generally done with a non - sneak attack critical . For example , Lincoln ' s repeater has a base damage of 50 ( might be different with perks , weapon condition , and skill ) and a critical damage of 50 , so a basic critical hit would do 100 damage ( unless you have the Better Criticals perk ) . When a sneak attack critical is dealt , the damage completely doubles , so the Sneak Attack Critical gives a whopping 200 damage ( 250 with Better Criticals ) . " Fallout : Brotherhood of Steel " . In " " , the system works much like " Fallout 3 " , when a weapon is fired , it has a predefined , specific percentage chance of getting a critical hit ) which is just to exceed the maximum limit of damage for a weapon . " Fallout 4 " . " Fallout 4 ' s " critical hit system removes the chance - based critical hit trigger , replacing it with a critical meter which builds up with each successful V . A . T . S . hit and , when filled , can then be triggered by the player just before any V . A . T . S . attack , guaranteeing a hit with extra damage . The rate that the critical meter fills increases with the character ' s Luck . Outside of V . A . T . S . critical hits cannot occur unless something increases your critical hit chance , such as with Overdrive , or if the attack is a Sneak Attack . This can be confirmed by looking at the " Combat - Critical Strikes " statistic in the Pip - Boy . The number of critical strikes will always equal the number of times a Critical was activated in V . A . T . S . plus the number of sneak attacks . Note that although the Pip - Boy counts a sneak attack as a critical hit , a sneak attack does not count as a critical hit for purposes of critical hit damage bonuses . Critical Damage . Weapons have a predefined critical damage which is added when a critical hit is executed , usually equal to the displayed weapon damage ( including weapon mods ) . In " Fallout 4 " there are several ways to alter the critical hit damage . One way is through modifying a gun by adding , e . g . , a Calibrated receiver or Photon exciter . These two mods add 2 . 0 to the critical hit multiplier . For some weapons there are receiver mods that will increase the critical damage even further , such as the Photon agitator which will add 4 . 0 to the critical hit multiplier . Critical damage can also be increased in small increments by reading perk magazines and collecting bobbleheads . " Damage " : Weapon damage , including workshop mods and strength multiplier ( 1 + 0 . 1 * STR ) , but excluding perks and other bonuses . " Damage " : Damage displayed in PipBoy ( PipBoy cuts off decimal places ) " CriticalMultiplier " = 1 + WeaponModBonus ( 2 . 0 … 4 . 0 ) + BobbleheadBonus ( 0 . 25 ) + MagazineBonus ( 0 . 05 … 0 . 5 ) + Better Criticals ( 0 . 5 … 1 . 5 ) Ranged Combat Melee / Unarmed Combat " Fallout Shelter " . In " Fallout Shelter " , critical hits only occur when on quests or exploring radiant locations while wandering the wasteland . As a dweller fights , they will randomly trigger a critical hit according to an invisible meter that fills as they fight ; a higher Luck stat causes the meter to fill faster , for more frequent critical hits . If an enemy is killed without using a critical hit against them , the meter will remain filled , allowing a critical hit to be " saved " for other enemies . When a critical hit occurs , a crosshair icon will appear over the currently targeted enemy . Tapping the icon will cause it to grow , and four crosshairs will move back and forth from the center of the targeting dot . Tapping the screen again will stop the crosshairs ; the closer they are to the center , the more damage the critical hit does . Damage ranges from 1 . 25 normal damage at the further point , to 5 times normal damage when the crosshairs are stopped directly in the middle . The higher the dweller ' s Perception , the slower the crosshairs move and thus the easier it is to deal higher damage .