Critical hit

A critical hit (Japanese: ''' ') is a (generally) random event that multiplies the damage of a damage-dealing move. When one occurs, the game will display the message "A critical hit!" (Japanese: Hit a pressure point!) after the damage is dealt.

Damage
When a move lands a critical hit, the attacker's level will be doubled during damage calculation, which approximately (but not quite) doubles the damage dealt. A rough formula for the damage multiplier is  where L is the attacker's level; as a result, lower-leveled Pokémon have a smaller critical hit boost than higher-leveled Pokémon. For example, a level 5 Pokémon will inflict about 1.5× damage on a critical hit, while a level 20 Pokémon will inflict 1.8× and a level 95 Pokémon will inflict 1.95×.

Critical hits ignore all stat stage modifiers and the halved from. This includes beneficial stat modifiers as well, making it possible for a critical hit to deal less damage than a non-critical hit if the attacker has at least doubled their Attack/ or the target's /Special is at least halved.

Probability
Whether a move scores a critical hit is determined by comparing a 1-byte random number (0 to 255) against a 1-byte threshold value (also 0 to 255); if the random number is less than the threshold, the Pokémon scores a critical hit. If the threshold value is T, then this means the probability (P) of scoring a critical hit is. (It is impossible for a critical hit to be guaranteed; there will always be at least a 1/256 chance that a critical hit will not be scored.)

The value of T is based on a Pokémon's base. For a normal move, T is half the base Speed:
 * or

Due to a bug, and Dire Hit lower a Pokémon's chance of scoring a critical hit instead of raising it, dividing T by 4:
 * or

If the move being used has a high critical-hit ratio (,, , or ), T is multiplied by 8:
 * or

Both effects may also be active at the same time. This would result in:
 * or

At all times, the maximum value for T is 255 (which equally means the maximum value for P is 255/256). All operations that factor into T are also integer operations (meaning divisions are rounded down to the nearest whole number). (Note that the division in  is not rounded.) Due to the process the game uses to compute T, BaseSpeed is also effectively rounded down to the nearest even number.

In Pokémon Stadium
In, the threshold value T is determined by a different formula.

For a normal move, T is:
 * or

is slightly more complicated than in the core games, but it does correctly raise the chance of a critical hit instead of lowering it:
 * or

If the move being used has a high critical-hit ratio (,, , or ), T is multiplied by 8:
 * or

If both effects are active at the same time, then:
 * or

Since 236 * 4 is well beyond 255, any Pokémon will have a maximum chance to score a critical hit if both effects are active.

As with the core games, the maximum value for T is always 255 (or 255/256 for P) and any divisions that factor into T are rounded down to the nearest whole number. Due to the process the game uses to compute T, BaseSpeed is also effectively rounded down to the nearest multiple of 4.

Damage
In Generations -, a critical hit deals 2 times the damage a move would otherwise do. From Generation onwards, a critical hit deals 1.5 times a move's normal damage.

In Generation II, when a move scores a critical hit, all stat stage modifiers, the halved Attack from burn, and the defensive boosts from and  are ignored if the target's defending stat stage ( or ) is greater than or equal to the attacker's attacking stat stage ( or ). From Generation III onwards, when a move scores a critical hit, the attacker's negative stat stages, the defender's positive stat stages, and the defensive boosts from, , and are always ignored. However, the halved Attack from burn is no longer ignored.


 * Examples
 * If the attacker is using a physical move and is at +2 Attack stages while the target is at +1 Defense stage...
 * Gen II: a critical hit will not ignore either stat. (Damage with a critical hit will have an 8/3× modifier.)
 * Gen III-V: a critical hit will ignore the Defense boost. (Damage with a critical hit will have a 4× modifier.)
 * Gen VI+: a critical hit will ignore the Defense boost. (Damage with a critical hit will have a 3× modifier.)
 * If the attacker is using a physical move and is at -1 Attack stages while the target is at -2 Defense stage...
 * Gen II: a critical hit will not ignore either stat. (Damage with a critical hit will have a 2.64× modifier.)
 * Gen III-V: a critical hit will ignore the Attack drop. (Damage with a critical hit will have a 4× modifier.)
 * Gen VI+: a critical hit will ignore the Attack drop. (Damage with a critical hit will have a 3× modifier.)

Other factors
The Abilities and  and the effect of  will prevent any critical hit being scored on a Pokémon.

The moves and  will always result in a critical hit (unless prevented by one of the above effects). The move guarantees the next move to score a critical hit.

If a Pokémon with the Ability gets a critical hit, the damage dealt will be multiplied by an additional factor of 1.5.

Pokémon with the Ability will always score critical hits on  Pokémon (unless prevented by one of the above effects).

Probability
The probability of landing a critical hit is no longer based on the attacker's base Speed, but rather is based on a fixed formula for all Pokémon. Similar to stats, there are temporary in-battle stages used to determine the probability that a particular move will be a critical hit.

If a Pokémon has maximum affection, the probability from above is multiplied by 2.

An attacking move will start out at stage 0, but there are several ways to increase a move's stage as detailed in the table below. An effect cannot stack with another effect in the same column, including itself.

Note that it is possible for a Pokémon to acquire the effect of a Lansat Berry even if it is already holding another item, through the use of, , , or ; or by obtaining another item after consuming the Berry, such as via or.