Damage
Damage (Japanese: ダメージ damage) is a loss of a Pokémon's HP that happens as the result of a physical or special attack used against it by another Pokémon.
Damage calculation
This section is incomplete. Please feel free to edit this section to add missing information and complete it. Reason: Anything that may have potentially been missed or inaccurate 
Except for moves that deal direct damage, the damage dealt when a Pokémon uses a damaging move depends on its level, its effective Attack or Special Attack stat, the opponent's effective Defense or Special Defense stat, and the move's effective power. In addition, various factors of damage modification may also affect the damage dealt.
More precisely, damage is calculated in each Generation as:
Generation I
where:
 Level is the level of the attacking Pokémon.
 Critical is 2 for a critical hit, and 1 otherwise.
 A is the effective Attack stat of the attacking Pokémon if the used move is a physical move, or the effective Special stat of the attacking Pokémon if the used move is a special move (for a critical hit, all modifiers are ignored, and the unmodified Attack or Special is used instead). If either this or D are greater than 255, both are divided by 4 and rounded down.
 D is the effective Defense stat of the target if the used move is a physical move, or the effective Special stat of the target if the used move is an other special move (for a critical hit, all modifiers are ignored, and the unmodified Defense or Special is used instead). If the move is physical and the target has Reflect up, or if the move is special and the target has Light Screen up, this value is doubled (unless it is a critical hit). If the move is Explosion or Selfdestruct, this value is halved (rounded down, with a minimum of 1). If either this or A are greater than 255, both are divided by 4 and rounded down. Unlike future Generations, if this is 0, the division is not made equal to 0; rather, the game will try to divide by 0 and softlock, hanging indefinitely until it is turned off.
 Power is the power of the used move.
 STAB is the sametype attack bonus. This is equal to 1.5 if the move's type matches any of the user's types, and 1 if otherwise. Internally, it is recognized as an addition of the damage calculated thus far divided by 2, rounded down, then added to the damage calculated thus far.
 Type1 is the type effectiveness of the used move against the target's type that comes first in the type matchup table, or only type if it only has one type. This can be 0.5 (not very effective), 1 (normally effective), 2 (super effective).
 Type2 is the type effectiveness of the used move against the target's type that comes second in the type matchup table. This can be 0.5 (not very effective), 1 (normally effective), 2 (super effective). If the target only has one type, Type2 is 1. If this would result in 0 damage, the calculation ends here and the move is stated to have missed, even if it would've hit.
 random is realized as a multiplication by a random uniformly distributed integer between 217 and 255 (inclusive), followed by an integer division by 255. If the calculated damage thus far is 1, random is always 1.
Generation II
where:
 Level is the level of the attacking Pokémon. If the used move is Beat Up, L is instead the level of the Pokémon performing the strike.
 A is the effective Attack stat of the attacking Pokémon if the used move is a physical move, or the effective Special Attack stat of the attacking Pokémon if the used move is a special move (for a critical hit, if the target's Defense or Special Defense stat stage is greater than or equal to the attacker's Attack or Special Attack stat stage, all modifiers are ignored, and the unmodified Attack or Special is used instead). If the used move is Beat Up, A is instead the base Attack of the Pokémon performing the strike.
 D is the effective Defense stat of the target if the used move is a physical move, or the effective Special stat of the target if the used move is an other special move (for a critical hit, all modifiers are ignored, and the unmodified Defense or Special is used instead). If the move is physical and the target has Reflect up, or if the move is special and the target has Light Screen up, this value is doubled (unless it is a critical hit). If the move is Explosion or Selfdestruct, this value is halved (rounded down, with a minimum of 1). If the used move is Beat Up, D is instead the base Defense of the target.
 Power is the power of the used move.
 Item is 1.1 if the attacker is holding an typeenhancing held item corresponding to the attack type (for instance, the Magnet for an Electrictype move).
 Critical is 2 for a critical hit, and 1 otherwise. It is always is 1 if the used move is Flail, Reversal, or Future Sight.
 TK is 1, 2, or 3 for each successive hit of Triple Kick, or always 1 if the used move is not Triple Kick.
 Weather is 1.5 if a Watertype move is being used during rain or a Firetype move during harsh sunlight, and 0.5 if a Watertype move is used during harsh sunlight or SolarBeam or any Firetype move during rain, and 1 otherwise.
 Badge is 1.125 if the attacking Pokémon is controlled by the player and if the player has obtained the Badge corresponding to the used move's type, and 1 otherwise. This bonus is not applied in link battles or the Battle Tower.
 STAB is the sametype attack bonus. This is equal to 1.5 if the move's type matches any of the user's types, and 1 if otherwise.
 Type is the type effectiveness. This can be 0.25, 0.5 (not very effective), 1 (normally effective), 2, or 4 (super effective), depending on both the move's and target's types. If the used move is Struggle, Future Sight, or Beat Up, Type is always 1.
 MoveMod can be (and if the used move is not any of these, MoveMod is 1):
 If Rollout is used, , where n is the amount of successful and consecutive hits of the move, up to 4 (for the fifth hit), and d is 1 if Defense Curl was used beforehand and 0 otherwise.
 If Fury Cutter is used, , where n is the number of successful and consecutive uses of the move, up to 4.
 If Rage is used, an integer value corresponding to the Rage counter, i.e. the number of times the user of Rage has been damaged by an attack while using Rage.
 random is realized as a multiplication by a random uniformly distributed integer between 217 and 255 (inclusive), followed by an integer division by 255. random is always 1 if Flail or Reversal is used.
 DoubleDmg is 2 if the used move is Pursuit and the target is attempting to switch out, Stomp and the target has previously used Minimize, Gust or Twister and the target is in the semiinvulnerable turn of Fly, or Earthquake or Magnitude and the target is in the semiinvulnerable turn of Dig, and 1 otherwise.
Generation III
where:
 Level is the level of the attacking Pokémon. If the used move is Beat Up, L is instead the level of the Pokémon performing the strike.
 A is the effective Attack stat of the attacking Pokémon if the used move is a physical move, or the effective Special Attack stat of the attacking Pokémon if the used move is a special move (for a critical hit, negative Attack or Special Attack stat stages are ignored). If the used move is Beat Up, A is instead the base Attack of the Pokémon performing the strike.
 D is the effective Defense stat of the target if the used move is a physical move, or the effective Special Defense stat of the target if the used move is a special move (for a critical hit, positive Defense or Special Defense stat stages are ignored). If the used move is Beat Up, D is instead the base Defense of the target.
 Power is the effective power of the used move.
 Burn is 0.5 if the attacker is burned, its Ability is not Guts, and the used move is a physical move, and 1 otherwise.
 Screen is 0.5 if the used move is physical and Reflect is present on the target's side of the field, or special and Light Screen is present. For a Double Battle, Screen is instead 2/3, and 1 otherwise or if the used move lands a critical hit. However, if, in a Double Battle, when the move is executed, the only Pokémon on the target's side is the target, Screen remains as 0.5.
 Targets is 0.5 in Double Battles if the move targets both foes (unless it targets all other Pokémon, like Earthquake, and only if there is more than one such target when the move is executed, regardless of whether the move actually hits or can hit all the targets), and 1 otherwise.
 Weather is 1.5 if a Watertype move is being used during rain or a Firetype move during harsh sunlight, and 0.5 if a Watertype move is used during harsh sunlight, any Firetype move during rain, or SolarBeam during any nonclear weather besides harsh sunlight, and 1 otherwise or if any Pokémon on the field have the Ability Cloud Nine or Air Lock.
 FF is 1.5 if the used move is Firetype, and the attacker's Ability is Flash Fire that has been activated by a Firetype move, and 1 otherwise.
 Stockpile is 1, 2, or 3 if the used move is Spit Up, depending on how many Stockpiles have been used, or always 1 if the used move is not Spit Up.
 Critical is 2 for a critical hit, and 1 otherwise. It is always 1 if Future Sight, Doom Desire, or Spit Up is used, if the target's Ability is Battle Armor or Shell Armor, or if the battle is the first one against Poochyena^{RS}/Zigzagoon^{E} or the capture tutorial where Wally catches a Ralts.
 DoubleDmg is 2 if the used move is (and 1 if the used move is not any of these moves):
 Gust or Twister and the target is in the semiinvulnerable turn of Fly or Bounce.
 Stomp, Needle Arm, Astonish, or Extrasensory and the target has previously used Minimize.
 Surf or Whirlpool and the target is in the semiinvulnerable turn of Dive.
 Earthquake or Magnitude and the target is in the semiinvulnerable turn of Dig.
 Pursuit and the target is attempting to switch out.
 Facade and the user is poisoned, burned, or paralyzed.
 SmellingSalt and the target is paralyzed.
 Revenge and the attacker has been damaged by the target this turn.
 Weather Ball, there is nonclear weather, and no Pokémon on the field have the Ability Cloud Nine or Air Lock.
 Charge is 2 if the move is Electrictype and Charge takes effect, and 1 otherwise.
 HH is 1.5 if the attacker's ally in a Double Battle has used Helping Hand on it, and 1 otherwise.
 STAB is the sametype attack bonus. This is equal to 1.5 if the move's type matches any of the user's types and 1 if otherwise.
 Type1 is the type effectiveness of the used move against the target's first type (or only type, if it only has a single type). This can be 0.5 (not very effective), 1 (normally effective), or 2 (super effective). If the used move is Struggle, Future Sight, Beat Up, or Doom Desire, both Type1 and Type2 are always 1.
 Type2 is the type effectiveness of the used move against the target's second type. This can be 0.5 (not very effective), 1 (normally effective), or 2 (super effective). If the target only has a single type, Type2 is 1.
 random is realized as a multiplication by a random uniformly distributed integer between 85 and 100 (inclusive), followed by an integer division by 100. random is always 1 if Spit Up is used.
Generation IV
where:
 Level is the level of the attacking Pokémon. If the used move is Beat Up, L is instead the level of the Pokémon performing the strike.
 A is the effective Attack stat of the attacking Pokémon if the used move is a physical move, or the effective Special Attack stat of the attacking Pokémon if the used move is a special move (for a critical hit, negative Attack or Special Attack stat stages are ignored). If the used move is Beat Up, A is instead the base Attack of the Pokémon performing the strike.
 D is the effective Defense stat of the target if the used move is a physical move, or the effective Special Defense stat of the target if the used move is a special move (for a critical hit, positive Defense or Special Defense stat stages are ignored). If the used move is Beat Up, D is instead the base Defense of the target.
 Power is the effective power of the used move.
 Burn is 0.5 if the attacker is burned, its Ability is not Guts, and the used move is a physical move, and 1 otherwise.
 Screen is 0.5 if the used move is physical and Reflect is present on the target's side of the field, or special and Light Screen is present. For a Double Battle, Screen is instead 2/3; however, if in a Double Battle when the move is executed, the only Pokémon on the target's side of the field is the target (for moves with only one target), or there is only one target when the move is executed (for moves with more than one target), Screen remains as 0.5. Screen is 1 otherwise or if the used move lands a critical hit.
 Targets is 0.75 in Double Battles if the used move has more than one target (provided there is more than one such target when the move is executed, regardless of whether the move actually hits or can hit all the targets), and 1 otherwise.
 Weather is 1.5 if a Watertype move is being used during rain or a Firetype move during harsh sunlight, and 0.5 if a Watertype move is used during harsh sunlight or a Firetype move during rain, or SolarBeam during any nonclear weather besides harsh sunlight, and 1 otherwise or if any Pokémon on the field have the Ability Cloud Nine or Air Lock.
 FF is 1.5 if the used move is Firetype, and the attacker's Ability is Flash Fire that has been activated by a Firetype move, and 1 otherwise.
 Critical is 2 for a critical hit, 3 if the move lands a critical hit and the attacker's Ability is Sniper, and 1 otherwise. It is always 1 if Future Sight or Doom Desire is used, the target's Ability is Battle Armor or Shell Armor, the target is under the effect of Lucky Chant, or if the battle is the first one against Starly^{DP}.
 Item is 1.3 if the attacker is holding a Life Orb, if the attacker is holding a Metronome, where n is the amount of times the same move has been successfully and consecutively used, up to 10, and 1 otherwise.
 First is 1.5 if the used move was stolen with Me First.
 random is realized a random integer from 85 to 100, inclusive, divided by 100. random is always 1 if Spit Up is used.
 STAB is the sametype attack bonus. This is equal to 1.5 if the move's type matches any of the user's types, 2 if the user of the move additionally has Adaptability, and 1 if otherwise.
 Type1 is the type effectiveness of the used move against the target's first type (or only type, if it only has a single type). This can be 0.5 (not very effective), 1 (normally effective), or 2 (super effective). If the used move is Struggle, Future Sight, Beat Up, or Doom Desire, both Type1 and Type2 are always 1.
 Type2 is the type effectiveness of the used move against the target's second type. This can be 0.5 (not very effective), 1 (normally effective), or 2 (super effective). If the target only has a single type, Type2 is 1.
 SRF is 0.75 if the used move is super effective, the target's Ability is Solid Rock or Filter, and the attacker's Ability is not Mold Breaker, and 1 otherwise.
 EB is 1.2 if the used move is super effective and the attacker is holding an Expert Belt, and 1 otherwise.
 TL is 2 if the used move is not very effective and the attacker's Ability is Tinted Lens, and 1 otherwise.
 Berry is 0.5 if the used move is super effective and the target is holding the Berry that weakens it, or Normaltype and the target is holding a Chilan Berry, and 1 otherwise.
Generation V onward
Unless otherwise specified, all divisions and multiplications past the initial base damage calculation are rounded to the nearest integer if the result is not an integer (rounding down at 0.5).
where
 Level is the level of the attacking Pokémon.
 A is the effective Attack stat of the attacking Pokémon if the used move is a physical move, or the effective Special Attack stat of the attacking Pokémon if the used move is a special move (ignoring negative stat stages for a critical hit).
 D is the effective Defense stat of the target if the used move is a physical move or a special move that uses the target's Defense stat, or the effective Special Defense of the target if the used move is an other special move (ignoring positive stat stages for a critical hit).
 Power is the effective power of the used move.
 Targets is 0.75 (0.5 in Battle Royals) if the move has more than one target when the move is executed, and 1 otherwise.
 PB is 0.25 (0.5 in Generation VI) if the move is the second strike of Parental Bond, and 1 otherwise.
 Weather is 1.5 if a Watertype move is being used during rain or a Firetype move or Hydro Steam during harsh sunlight, and 0.5 if a Watertype move (besides Hydro Steam) is used during harsh sunlight or a Firetype move during rain, and 1 otherwise or if any Pokémon on the field have the Ability Cloud Nine or Air Lock.
 GlaiveRush is 2 if the target used the move Glaive Rush in the previous turn, or 1 otherwise.
 Critical is 1.5 (2 in Generation V) for a critical hit, and 1 otherwise. Decimals are rounded down to the nearest integer. It is always 1 if the target's Ability is Battle Armor or Shell Armor or if the target is under the effect of Lucky Chant.
 Conversely, unless critical hits are prevented entirely by one of the above effects, Critical will always be 1.5 (or 2 in Generation V) if the used move is Storm Throw, Frost Breath, Zippy Zap, Surging Strikes, Wicked Blow, or Flower Trick, the target is poisoned and the attacker's Ability is Merciless, or if the user is under the effect of Laser Focus.
 random is a random factor. Namely, it is recognized as a multiplication from a random integer between 85 and 100, inclusive, then divided by 100. Decimals are rounded down to the nearest integer.
 If the battle is taking place as a Pokéstar Studios film, random is always 1.
 STAB is the sametype attack bonus. This is equal to 1.5 if the move's type matches any of the user's types, 2 if the user of the move additionally has Adaptability, and 1 otherwise or if the attacker and/or used move is typeless. If the used move is a combination Pledge move, STAB is always 1.5 (or 2 if the user's Ability is Adaptability). When Terastalized, STAB is (if not 1):
 1.5 if the move's type matches either the Pokemon's original type(s) or a different Tera Type from its original types, and the attacker's Ability is not Adaptability.
 2 if the move's type matches the same Tera Type as one of the Pokemon's original types and the attacker's Ability is not Adaptability, or the situation above, if the attacker's Ability is Adaptability.
 However, if STAB only applies from the attacker's original type(s), not its Tera Type, STAB will always be 1.5, even if the attacker's Ability is Adaptability.
 2.25 if the move's type matches the same Tera Type as one of the Pokemon's original types and the attacker's Ability is Adaptability.
 Type is the type effectiveness. This can be 0.125, 0.25, 0.5 (not very effective); 1 (normally effective); 2, 4, or 8 (super effective), depending on both the move's and target's types. The 0.125 and 8 can potentially be obtained on a Pokémon under the effect of Forest's Curse or TrickorTreat. If the used move is Struggle or typeless Revelation Dance, or the target is typeless, Type is always 1. Decimals are rounded down to the nearest integer. Certain effects can modify this, namely:
 If the target is an ungrounded Flyingtype that is not being grounded by any other effect and is holding an Iron Ball or under the effect of Thousand Arrows, Type is equal to 1.
 If the target is a grounded Flyingtype (unless grounded by an Iron Ball or Thousand Arrows, as above), treat Ground's matchup against Flying as 1.
 If the target is holding a Ring Target and the used move is of a type it would otherwise be immune to, treat that particular type matchup as 1.
 If the attacker's Ability is Scrappy, treat Normal and Fighting's type matchups against Ghost as 1.
 If the target is under the effect of Foresight, Odor Sleuth or Miracle Eye, and the target is of a type that would otherwise grant immunity to the used move, treat that particular type matchup as 1.
 If the used move is FreezeDry, treat the move's type's matchup against Water as 2.
 If the used move is Flying Press, consider both the move's type effectiveness and the Flying type's against the target, and multiply them together.
 If strong winds are in effect and the used move would be super effective against Flying, treat the type matchup against Flying as 1 instead.
 If the target is under the effect of Tar Shot and the used move is Firetype, multiply Type by 2.
 Burn is 0.5 if the attacker is burned, its Ability is not Guts, and the used move is a physical move (other than Facade from Generation VI onward), and 1 otherwise.
 other is 1 in most cases, and a different multiplier when specific interactions of moves, Abilities, or items take effect, in this order (and if multiple moves, Abilities, or items take effect, they do so in the order of the outofbattle Speed stats of the Pokémon with them):
Effect  Value  Detail 

Behemoth Blade, Behemoth Bash, and Dynamax Cannon  2  If the target is Dynamaxed and the used move is one of these three 
Moves interacting with Minimize  2  If the target has used Minimize and the used move is one listed here 
Earthquake and Magnitude  2  If the target is in the semiinvulnerable turn of Dig and the used move is one of these two 
Surf and Whirlpool  2  If the target is in the semiinvulnerable turn of Dive and the used move is one of these two 
Reflect, Light Screen, and Aurora Veil  0.5 *  If in effect on the target's side, the used move is physical (Reflect), special (Light Screen), or either (Aurora Veil), the move is not a critical hit, and the user's Ability is not Infiltrator. Does not stack, even if e.g. Light Screen and Aurora Veil are active at the same time. 
Collision Course and Electro Drift  5461/4096 (~1.3333)  If either of these are the used move and it is super effective 
Multiscale and Shadow Shield  0.5  If the target has this Ability and is at full health 
Fluffy  0.5  If the target has this Ability and the used move makes contact 
Punk Rock  0.5  If the target has this Ability and the used move is soundbased 
Ice Scales  0.5  If the target has this Ability and the used move is a special move 
Friend Guard  0.75  If an ally of the target has this Ability 
Filter, Prism Armor and Solid Rock  0.75  If the target has this Ability and the used move is super effective (Type > 1) 
Neuroforce  1.25  If the user has this Ability and the used move is super effective (Type > 1) 
Sniper  1.5  If the attacker has this Ability and the move lands a critical hit 
Tinted Lens  2  If the attacker has this Ability and the used move is not very effective (Type < 1) 
Fluffy  2  If the target has this Ability and the used move is Firetype 
Typeresist Berries  0.5 *  If held by the target, the move is of the corresponding type, and is super effective (Type > 1); for the Chilan Berry, the used move must simply only be Normaltype 
Expert Belt  4915/4096 (~1.2)  If held by the attacker and the move is super effective (Type > 1) 
Life Orb  5324/4096 (~1.3)  If held by the attacker 
Metronome  Varies  1 + (819/4096 (~0.2) per successful consecutive use of the same move) if held by the attacker, but no more than 2 
 If multiple effects influence the other value, their values stack multiplicatively, in the order listed above. This is done by starting at 4096, multiplying it by each number above in the order listed above, and rounding to the nearest integer whenever the result is not an integer (rounding up at 0.5). When the final value is obtained, it is divided by 4096, and this becomes other. For example, if both Multiscale and a Chilan Berry take effect, other is = 0.25.
 ZMove is 0.25 if the move is a ZMove or Max Move and the target would be protected from that move (e.g. by Protect), and 1 otherwise. (If this multiplier is applied, a message is displayed that the target "couldn't fully protect" itself.)
 TeraShield is applied in Tera Raid Battles when the Raid boss's shield is active. It is 0.2 if the player's Pokémon is not Terastallized, 0.35 if it is but the used move is not of its Tera Type, and 0.75 if it is and the used move is of its Tera Type. The result is subject to standard rounding (rounding up at 0.5).
In the first four generations, during the calculation, all operations are carried out on integers internally—this means that all division operations are truncated integer division (i.e. rounding down if the result is not an integer), and the results of multiplication operations are rounded down afterwards (truncating any fractional part). From Generation V onward, there are three different types of rounding; a flooring (the same as previous generations), rounding to the nearest integer while rounding down at 0.5, and rounding to the nearest integer while rounding up at 0.5.
If the calculation yields 0, the move will deal 1 HP damage instead (unless Type is equal to 0, in which case damage calculation is skipped entirely); however, in Generation V, a move may deal 0 damage when other is less than 1, because the routine to prevent 0 damage is erroneously performed before applying the other factor.
Example
Imagine a level 75 Glaceon that does not suffer a burn and holds no item with an effective Attack stat of 123 uses Ice Fang (an Icetype physical move with a power of 65) against a Garchomp with an effective Defense stat of 163 in Generation VI, and does not land a critical hit. Then, the move will receive STAB, because Glaceon's Ice type matches the move's: STAB = 1.5. Additionally, Garchomp is Dragon/Ground, and therefore has a double weakness to the move's Ice type: Type = 4. All other (nonrandom) modifiers will be 1. This effectively gives
That means Ice Fang will do between 168 and 196 HP damage, depending on luck.
If the same Glaceon holds a Muscle Band and its Ice Fang lands a critical hit against Garchomp, Ice Fang's effective power will be boosted by the Muscle Band by (approximately) 10% to become 71, and it will also be Critical = 1.5:
That means Ice Fang will now do between 268 and 324 HP damage, depending on luck.
Pokémon Legends: Arceus
In Pokémon Legends: Arceus, a new damage calculation method^{[1]} is used: All multiplications and divisions are rounded down to the nearest integer unless specified.
where
 is the level of the attacking Pokémon.
 is the effective Attack stat of the attacking Pokémon if the used move is a physical move, or the effective Special Attack stat of the attacking Pokémon if the used move is a special move.
 If the attacker is under Slow Start, then the physical Attack stat will be halved at this step of the calculation.
 If the attacker is filled with Wild Might or Terrible Might, both Attack stats will be multiplied by 1.5.
 is the effective Defense stat of the target if the used move is a physical move, or the effective Special Defense of the target if the used move is an other special move.
 If the target is filled with Wild Might or Terrible Might, both Defense stats will be multiplied by 1.5.
 is the power of the used move.
 is 1.5 if the attacker's offensive stats are boosted, 1 if they are neutral, or 0.66 if they are lowered. If the attacker and target have the same "stage" of offensive and defensive stats, both this and DefMod are 1. This is applied by first multiplying AtkMod by DefMod, then multiplying the result by the calculated damage thus far and rounding down to the nearest integer.
 is 1.5 if the target's defensive stats are lowered, 1 if they are neutral, or 0.66 if they are boosted.
 is realized as a multiplication by a random integer between 85 and 100 (inclusive), and divided by 100.
 Splinter damage (from Ceaseless Edge, Pin Missile, Spikes, Stealth Rock and Stone Axe) is not subject to this factor.
 is the type effectiveness. This can be 0.4, 0.5 (not very effective); 1 (normally effective); 2, or 2.5 (super effective), depending on both the move's and target's types.
 is 0.75 if a Firetype move is used during rain, and 1 otherwise. The result is rounded to the nearest integer (rounding down at 0.5).
 is 1.5 for a critical hit, and 1 otherwise.
 is the sametype attack bonus. This is equal to 1.25 if the move's type matches any of the user's types, and 1 otherwise. The result is rounded to the nearest integer (rounding down at 0.5).
 is 0.5 if the attacker is burned and the used move is physical, or if the attacker is frostbitten and the used move is special, and 1 otherwise.
 is 1.33 if the target is drowsy, and 1 otherwise.
 is 1.5 if the attacker is fixated, and 1 otherwise.
 is 1.33 if the target is fixated, and 1 otherwise.
 is 1.5 if the attacker is primed, and 1 otherwise.
Pokémon GO
In Pokémon GO, damage is calculated differently due to different variables existing in the game.
where
 is the power of the move used
 is the Attack stat of the attacking Pokémon
 is the Defense stat of the Pokémon being attacked
 For Shadow Pokémon:
 is applied to
 is applied to
and
where
 is the type effectiveness, which is calculated differently in GO, using multipliers of base 1.6 instead of 2.
 is the sametype attack bonus. This is equal to 1.2 if the move's type matches any of the user's types, and 1 if otherwise.
 The following variables are applied in Gym and Raid Battles only, and are 1 otherwise.
 is 1.2 if the move used has a weatherboosted type, and otherwise.
 is applied when battling with Friends and varies depending on the Friendship level.
 1.03 if Good Friends
 1.05 if Great Friends
 1.07 if Ultra Friends
 1.1 if Best Friends
 1 otherwise
 is if the attack was successfully dodged, and if otherwise.
 Gym defenders and Raid Bosses will never dodge a player's attacks
 is greater than 1 when there is one or more MegaEvolved Pokémon on the battlefield.
 1.1 if none of the MegaEvolved Pokémon have the same type as the move
 1.3 if one or more MegaEvolved Pokémon have the same type as the move
 The following variables are applied in Trainer Battles only, and are 1 otherwise.
 is for all attacks used in a Trainer Battle.
 is applied only for Charged Attacks, and its value depends on the player's score during the minigame. The possible ranges are
 if "Excellent!"
 if "Great!"
 if "Nice!"
 otherwise
By the damage formula, moves that have a power of 0 such as Splash and Yawn will always do 1 HP damage.
Trivia
 In Pokémon Ruby and Sapphire, if the player's Pokémon deals over 33037 HP damage, the Pokémon will faint, but the HP bar will not be drained; if it deals exactly 33037 HP, the HP bar will be drained automatically.
 In Generation V onward, the amount of damage that can be dealt in a single attack is capped at 65535. In addition, an overflow can occur during the calculation of very high damage amounts, causing the actual damage dealt to be much lower than expected.^{[2]}
 Likewise, in Pokémon FireRed and LeafGreen and Pokémon Emerald specifically, the maximum amount of damage that can be dealt in one hit is 10000.^{[3]}^{[4]}
 In Pokémon Battle Revolution, the HP bar will change with a different animation depending on the move's type (recovery, recoil damage and indirect damage use the Normaltype animation), as shown below.
Normal  Fighting  Flying  Poison 

Ground  Rock  Bug  Ghost 
Steel  Fire  Water  Grass 
Electric  Psychic  Ice  Dragon 
Dark 
In other languages

External links
 The Complete Damage Formula for Black & White (Smogon University)
 DaWoblefet’s Damage Dissertation A Complete Guide to the Damage Formula
References
 ↑ https://twitter.com/Sibuna_Switch/status/1553954748809764864
 ↑ https://www.smogon.com/forums/threads/ultrasunultramoonbattlemechanicsresearchreadpost2.3620030/page9#post7760159
 ↑ https://github.com/pret/pokefirered/blob/master/src/battle_script_commands.c#L1726
 ↑ https://github.com/pret/pokeemerald/blob/aa9ccbf1940d28c2342eccad77b8a6a44f592794/src/battle_script_commands.c#L1821
This game mechanic article is part of Project Games, a Bulbapedia project that aims to write comprehensive articles on the Pokémon games. 