Damage

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.

Super effective

When a move is super effective, it does double the damage it would normally do. For example, a move like Megahorn used against a Template:Type2 Pokémon will be super effective because Template:Type2 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 Template:Type2 move like Surf will be damaged four times as much by the move as it would normally be, because both Rock and Ground Pokémon are weak to Water moves.

Not very effective

When a move is not very effective, it does 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 Template:Type2 move. Likewise, a Normal/Flying Pokémon hit by a Template:Type2 move will be damaged normally, as the super-effectiveness of Fighting against Normal is canceled out by the not-very-effectiveness of Fighting against Flying.

Not effective

When a move is not effective, it does not damage the Pokémon at all and that Pokémon is "immune" to that type. This immunity includes status moves of that type. For example, the Template:Type2 move Thunderbolt will have no affect on a Template:Type2 Pokémon such as Garchomp. Likewise, using the move Thunder Wave will prove useless and yields a "It does not affect Garchomp" (whereas a Confuse Ray that simply missed yields "It did not affect Garchomp"). Certain types are immune to specific moves, such as Template:Type2 Pokémon being immune to Leech Seed.

Critical hit

A move will sometimes get a critical hit against another Pokémon, some moves more than others. This will double the damage done after super effective/not very effective calculations occur, leading to the ability for a doubly-super effective move that gets a critical hit to do eight times as much damage as it would.

Critical hits work through levels, which determine the chance for a critical hit:

Level Percentage Moves
1 6.25% Normal moves
2 12.5% Moves with an increased critical hit rate: Slash, Stone Edge etc.
3 25% Moves used by Farfetch'd with the Stick attached
4 33.3% Critical hit moves used in combination with Super Luck
5 50% Critical hit moves used in combination with Super Luck and a Razor Claw or Scope Lens.

Scope Lens and Razor Claw add 1 level each, the Stick adds 2 levels (for Farfetch'd only), Focus Energy adds a level, Super Luck doubles the amount of levels and goes before the items are calculated in. 50% is the cap, no situation reaches above it.

When a move is a critical hit, damage is calculated based on either the modified or unmodified attack and defense stats, whichever is more advantageous to the attacker. For example, an attacker who has used Swords Dance and then makes a critical hit will get the benefit of the increased Attack, while one affected by Charm will use its normal Attack score. Another example would be if a team had Light Screen or Reflect on it and the attacker scored a critical on the team with the certain wall; the defense added by the wall would then be ignored, and will do double normal damage.

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 Template:Type2 move used by a Fire-type Pokémon. Dual-typed 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.

Weather

Main article: Weather conditions

Template:Type2 and Template:Type2 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.

Abilities

Main article: Abilities

Abilities come in a wide variety, and have various effects on damage modification. These affects 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: