Damage modification is a system of multipliers used to change the damage dealt in a battle. These modifiers affect how the damage is calculated by multiplying the move's base power in various ways. These modifiers range from doubling to halving and even negating the damage done.
Since each move has a type, its effectiveness (Japanese: 効果 effectiveness) is largely determined by the targeted Pokémon's type. Moves can have regular effectiveness or be super effective, not very effective, or not effective at all. The effectiveness of types against one another has varied among generations, see this page.
- "Super effective" redirects here. For the webcomic, see Super Effective (webcomic).
- "It's super effective" redirects here. For the podcast, see It's Super Effective (podcast).
- "Weakness" redirects here. For the TCG mechanic, see Appendix:Glossary (TCG) → Weakness.
When a move is super effective (Japanese: 効果はバツグン super effective), it inflicts double the damage it would normally do. For example, a move like Megahorn used against a Psychic-type Pokémon will be super effective because Bug-type moves are super effective against Psychic types. This effect can stack up; for example, a Pokémon that is Rock/Ground-type and is hit by a Water-type move like Surf will be damaged four times as much by the move as a Normal-type Pokémon would be, because both Rock and Ground Pokémon are weak to Water moves.
In Pokémon GO, super effective moves deal only 1.25x the damage, instead of 2x.
Not very effective
- "Resistance" redirects here. For the TCG mechanic, see Appendix:Glossary (TCG) → Resistance.
When a move is not very effective (Japanese: 効果は今一つ not very effective), or resistant, it deals half of the damage it would normally do. This works exactly like super effective moves, and can stack up. For example, a Steel/Rock-type Pokémon will be damaged by a quarter of the amount by a Normal-type move. Likewise, a Normal/Flying-type Pokémon hit by a Fighting-type move will be damaged normally, as Normal's weakness to Fighting is canceled out by Flying's resistance to it.
In Pokémon GO, not very effective moves deal 0.8x damage, instead of 0.5x.
When a move is not effective (Japanese: 効果がない not effective), it does not damage the Pokémon at all and that Pokémon is "immune" to all attacks of that type; the move will yield a message of "It doesn't affect Pokémon..." Certain types are also immune to specific status moves, such as Ground-type Pokémon being immune to the Electric-type Thunder Wave, or Grass-type Pokémon being immune to Leech Seed as well as powder and spore moves.
- Main article: Critical hit
A move will sometimes inflict a critical hit against another Pokémon. This will increase the damage done by 1.5× (2× prior to Generation VI) prior to type effectiveness calculations.
From Generation II onward, critical hits cause the effects of Light Screen and Reflect to be ignored. From Generation III onward, a critical hit additionally causes the attacker's negative stat changes and the defender's positive stat changes to be ignored.
There are no critical hits in Pokémon GO.
Same-type attack bonus
- Main article: Same-type attack bonus
A move used by a Pokémon that is of the same type as the move itself will do 1.5x of its normal damage, such as a Fire-type move used by a Fire-type Pokémon. Dual-type Pokémon will receive this bonus for both of their types, and a Pokémon whose type can change in-battle will receive the bonus for whatever type they are when they make the move. Pokémon with Adaptability have this increased to 2x (an effective boost of ~33.3%).
In Pokémon GO, the same-type attack bonus is 1.25x, instead of 1.5x.
- Main article: Weather
Water-type and Fire-type moves' damage are modified by rain and harsh sunlight. During rain, Water-type moves do 50% more damage and Fire-type moves do 50% less damage. During harsh sunlight, Fire-type moves do 50% more damage and Water-type moves do 50% less damage. During heavy rain, Fire-type moves cannot be executed; during extremely harsh sunlight, Water-type moves cannot be executed. A mysterious air current halves all super-effective damage done to Flying-type Pokémon. All these effects are ignored when a Pokémon with Cloud Nine or Air Lock is on the field.
Terrain affects Pokémon that are grounded and will either power up their moves or halve the power of moves targeting them depending on the terrain. Electric Terrain increases the power of Electric-type moves used by grounded Pokémon by 50%. Grassy Terrain increases the power of Grass-type moves used by grounded Pokémon by 50%. Psychic Terrain increases the power of Psychic-type moves used by grounded Pokémon by 50%. Misty Terrain decreases the power of Dragon-type moves targeting grounded Pokémon by 50%.
Flying types, Pokémon with Levitate, Pokémon holding an Air Balloon, and Pokémon under the effects of Magnet Rise or Telekinesis, do not experience these effects unless they hold an Iron Ball, Gravity is in effect, or they are under the effect of Ingrain.
- Main article: Ability
Abilities come in a wide variety, and have various effects on damage modification. These effects range from increasing and decreasing the power of moves of a specific type, granting immunities, and even changing the power of moves affected by other damage modifiers. These Abilities include:
- Blaze, Overgrow, Torrent and Swarm increase the power of Fire-type, Grass-type, Water-type and Bug-type moves respectively by 50% when the user's HP falls below 33%.
- Guts and Marvel Scale will increase the user's Attack and Defense respectively by 50% if inflicted with a non-volatile status condition. Toxic Boost and Flare Boost increase the user's Attack by 50% if inflicted with poison, and increase the user's Special Attack by 50% if inflicted with burn, respectively.
- Thick Fat decreases the damage dealt to the user by opponents' Fire-type and Ice-type moves by 50%. Heatproof decreases the damage dealt to the user by opponents' Fire-type moves by 50%.
- Volt Absorb and Water Absorb grant immunity to Electric-type and Water-type moves respectively, healing the user's HP by 25% instead.
- Dry Skin works in part like Water Absorb, healing the user when hit with a Water-type move, but it also causes the Pokémon to receive 25% additional damage from Fire-type attacks.
- Flash Fire negates the effect of opponents' Fire-type moves and instead increases the power of the ability's user's own Fire-type attacks by 50%.
- Mold Breaker, Teravolt, Turboblaze, Sunsteel Strike and Moongeist Beam ignore all Ability-based modifiers to the user's moves except for Shadow Shield and Prism Armor. Core Enforcer removes the target's Ability-based modifiers if the target has already made a move in the same turn.
- Adaptability increases the STAB multiplier for moves of the same type as the user from 1.5× to 2×.
- Hustle boosts the Attack stat of the user by 50%.
- Pure Power and Huge Power both double the user's Attack stat.
- Technician increases the power of the user's moves with base power 60 or less by 50%.
- Sniper increases the damage of the user's critical hits by 50%.
- Tinted Lens doubles the power of the user's moves that are not very effective.
- Solid Rock, Filter and Prism Armor each reduce the power of super-effective moves on the user by 25%.
- Iron Fist increases the damage of punching moves by 20%.
- Mega Launcher increases the damage of aura and pulse moves by 50%. Strong Jaw increases the damage of biting moves by 50%.
- Fur Coat halves all damage from physical moves to the user.
- Fluffy halves all damage from contact moves to the user and doubles the damage taken from Fire-type moves.
- Multiscale and Shadow Shield halve all damage to the user when the user has full HP.
- Plus and Minus boost the Special Attack of allies that have one of these abilities as well by 50%.
- Rivalry increases the power of moves used by the user by 25% when the target has the same gender as the user, but decreases the power of moves by 25% if the target is of the opposite gender as the user. This ability has no effect if the target is genderless.
- Solar Power increases the user's Special Attack by 50% in harsh sunlight at the cost of losing 12.5% of its maximum HP at the end of each turn. Flower Gift increases the Attack and Special Defense of the Pokémon with this Ability and its allies by 50% in harsh sunlight.
- Slow Start halves the user's Attack and Speed stats for the first 5 turns the user is out on the battlefield. Defeatist halves the user's Attack and Special Attack when the user's HP drops below 50%.
- Reckless increases the base power of moves which cause recoil or crash damage by 20%, except Struggle.
- Sheer Force increases the base power of moves with secondary effects by 30% and prevents those secondary effects from occuring.
- Friend Guard reduces the damage done to the user's allies by 25%. Battery increases the power of allies' special moves by 30%.
- Analytic increases the power of the user's moves by 30% on targets of the move that have already made a move in that turn.
- Sand Force increases the power of the user's Rock, Ground and Steel-type moves by 30% in sandstorm.
- Tough Claws increases the power of the user's contact moves by 33%.
- Pixilate, Refrigerate, Aerilate and Galvanize change Normal-type moves to Fairy, Ice, Flying and Electric-type moves respectively, and increases the power of affected moves by 20% (30% in Generation VI). Normalize changes all moves to Normal-type and increases the base power of affected moves by 20% as of Generation VII.
- Parental Bond adds a second hit after each single-target attack move that does 25% of the damage of the first hit (50% in Generation VI).
- Dark Aura and Fairy Aura power up the Dark-type and Fairy-type moves (respectively) of all Pokémon on the field by 33%. If these Abilities are active at the same time as Aura Break, the base power of Dark- and Fairy-type moves will instead be divided by 1.33.
- Stakeout increases the power of moves by 50% if the selected target has switched out into a different Pokémon.
- Water Bubble halves the damage from Fire-type moves to the user and doubles the power of Water-type moves used by the user.
- Steelworker increases the damage of the user's Steel-type moves by 50%.
Some abilities are able to deal damage, these are:
- Rough Skin and Iron Barbs cause Pokémon that attack the user with a contact move to lose 12.5% of their maximum HP.
- Liquid Ooze causes Pokémon using an HP-draining move on the user to lose half the HP drained, rather than restoring it.
- Aftermath causes Pokémon that knock out the user with a contact move to lose 25% of their maximum HP.
- Bad Dreams deals damage to all sleeping Pokémon on the field (other than the user) equal to 12.5% of their maximum HP at the end of every turn.
- Innards Out deals damage equal to the user's remaining HP before getting knocked out to the Pokémon that knocked it out.
- See also: Type-enhancing item
Some held items increase the power of an attack by a small percentage. Most of these items boost attacks only of a certain type by 20%. Some items can also modify damage by boosting the attacker's offensive stats or the victim's defensive stats. Some Berries also weaken an opponent's super-effective move.
Other held items that modify damage include:
- Muscle Band boosts physical moves by 10%
- Wise Glasses boost special moves by 10%
- Expert Belt boosts super-effective attacks by 20%
- Life Orb boosts the power of all attacks by 30% (at a cost of 10% HP per damaging move used)
- Metronome boosts the power of moves used repeatedly
A number of other variables can affect the amount of damage caused by an attack.
- If the attacker is burned and their Ability is not Guts, their physical damage will be decreased by half.
- In a Double Battle, moves that hit multiple targets do 75% of the damage they do in one-on-one battles.
- Reflect and Light Screen decrease opponents' physical and special attacks, respectively, by 50% in a one-on-one battle and 33% in a Double Battle.
Every time a regular attack is executed, the actual damage caused is adjusted by a random multiplier - an integer percentage between 85% and 100%.
In Generations I and II, the random modifier is not an integer percentage. Instead of selecting a 4-bit integer, the game selects a random byte (that is, a value up to 255), repeatedly selecting a new one until the selected value is 217 or greater; the game afterwards multiplies the pre-adjustment damage by this number and divides it by 255. As a result, the randomization adjustment in these two generations goes between 217/255 (roughly 85.1%) and 255/255 (100%) in steps of 1/255, giving each value a uniform 1 in 39 chance of being selected (as opposed to 1 in 15 in later generations).
In all subsequent games, the random adjustment is determined by generating a 4-bit integer (0 through 15). The computer then subtracts it from 100, and then divides the result by 100 to get the final adjustment. This results in an integer percentage between 85% and 100%, with a uniform distribution.
The damage dealt when a Pokémon uses a damaging move depends on its Attack or Special Attack stat, the opponent's corresponding Defense or Special Defense stat, and the move's base power. In addition, the various factors of damage modification will also affect the damage dealt.
The damage formula is
- Level is the level of the attacking Pokémon.
- Attack and Defense are the working Attack and Defense stats of the attacking and defending Pokémon, respectively. If the attack is Special, the Special Attack and Special Defense stats are used instead. Some moves like Psystrike use stats other than what moves of this category would usually use (in case of Psystrike, it uses Special Attack and Defense).
- Base is the base power of the attack.
and Modifier is
- STAB is the same-type attack bonus. This is equal to 1.5 if the attack is of the same type as the user, and 1 if otherwise.
- Type is the type effectiveness. This can be either 0, 0.25, 0.5, 1, 2, or 4 depending on the type of attack and the type of the defending Pokémon.
- Critical is 2 for a critical hit in Generations I-V, 1.5 for a critical hit from Generation VI onwards, and 1 otherwise.
- other counts for things like held items, Abilities, field advantages, and whether the battle is a Double Battle or Triple Battle or not.
- random is a random number from 0.85 to 1.00.
Modifier is then plugged into the rest of the formula:
Garchomp is up next. Garchomp gets a critical hit (Critical = 2) on Earthquake, a physical Ground move with 100 base power. With its Ice type, Glaceon is neither weak nor resistant to Garchomp's attack, so Type = 1. Garchomp is Dragon/Ground, so it receives STAB, making STAB = 1.5. Say that Garchomp is also holding an Earth Plate, which powers up Ground-type moves by 20%. Then Other = 1.2.
Inserting the stats and Modifier in the formula yields:
Garchomp's attack will do anywhere from 241 to 284 damage, which is more than enough to take the Glaceon out in one hit.
- The highest potential damage dealt in a single attack can be achieved by Shuckle using Ice Ball.
- 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 Normal-type animation), as shown below.
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