From Bulbapedia, the community-driven Pokémon encyclopedia.
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 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 Glossary (TCG) → Weakness.
When a move is 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 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.
Not very effective
- "Resistance" redirects here. For the TCG mechanic, see Glossary (TCG) → Resistance.
When a move is 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 Pokémon will be damaged by a quarter of the amount by a Normal-type move. Likewise, a Normal/Flying 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.
When a move is 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 the 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.
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 150% 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 200% (an effective boost of ~33.3%).
- Main article: Weather conditions
Water-type and Fire-type moves' damage will be modified by rain and sunshine. If Rain Dance causes a downpour, Water-type moves will do 50% more damage and Fire-type moves will do 50% less damage. If Sunny Day causes harsh sunlight, Fire-type moves will do 50% more damage and Water-type moves will do 50% less damage.
- 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 will increase the user's Attack by 50% if inflicted with a burn, paralysis, or poison.
- 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%.
- Levitate provides immunity to Ground-type moves and Soundproof provides immunity to sound moves.
- 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 heals the user by 6.25% each turn during rain. However, it also causes the Pokémon to receive additional damage from Fire-type attacks and lose 6.25% of its HP in damage during sunshine.
- 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. Similarly, Motor Drive negates the effect of opponents' Electric-type moves and instead increases the user's Speed by one stage. These abilities include status moves like Will-O-Wisp and Thunder Wave.
- Mold Breaker, Teravolt, and Turboblaze remove all ability-based immunities to the user's moves.
- Scrappy allows the user to hit Ghost-types with Normal-type and Fighting-type damage-dealing moves.
- Drizzle, Drought, Sand Stream and Snow Warning cause permanent rain, sunshine, sandstorm, and hail respectively prior to generation VI, which limits the weather to 5 turns.
- 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%.
- Super Luck increases the user's critical hit ratio.
- Battle Armor and Shell Armor prevent critical hits being dealt to the user.
- Sniper increases the damage of a user's critical hits by 50%.
- Tinted Lens doubles the power of the user's moves that are not very effective.
- Solid Rock and Filter each reduce the power of super effective moves on the user by 25%.
- Wonder Guard gives the user immunity to all attacking moves that are not super effective.
- Iron Fist increases the damage of punching moves by 20%.
- Mega Launcher increases the damage of aura and pulse moves by 50%.
- The moves Storm Throw and Frost Breath can cancel out the 50% damage if used on certain types due to the moves always resulting in a critical hit, and can cause 4×, 6× or 12× multipliers if used on other types.
- 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:
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 does not have uniform probability for all percentages between 85 and 100. This is because the computer will generate a random number from 217 to 255 (217 is about 85.10% of 255), multiply it by 100, and then divide it by 255, to get the random number from 85 to 100 that the computer will divide by 100 to get the final adjustment.
As a result, the odd numbers from 85 to 89 and the even numbers from 90 to 98 have a 7.69% (3 in 39) probability of being chosen, while the even numbers from 86 to 88 and the odd numbers from 91 to 99 have a 5.13% (2 in 39) probability of being chosen. The number 100, the least probable number, has a mere 2.56% (1 in 39) chance of being chosen.
In all subsequent games, the random adjustment is determined by generating a 4 bit number (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 the same integer percentage between 85% and 100%, with an even distribution of occurrence.