Pokémon Black Version and Pokémon White Version - Descriptions of Common Effects
Effects that are common to many attacks are described below. Of the effects listed here, a Pokémon will remain poisoned, burned, paralysis, frozen, and asleep even when the Pokémon leaves the battle, including when a battle ends. (However, a Pokémon will stop being poisoned, burned, paralyzed, frozen, and asleep, as well as have full HP and PP, when it’s taken to a Pokémon Center nurse or placed in a PC storage box.) An effect can’t cause poison, burn, paralysis, freezing, or sleep against a Pokémon if it already has one of these five conditions or if it has fainted.
Burn (BRN)
If a Pokémon is burned, the damage from physical attacks it uses is halved, and it loses 1/8 of its maximum HP, rounded down (but not less than 1 HP), at the end of each turn. Fire types can’t become burned.
Poison (PSN)
If a Pokémon is poisoned, it loses 1/8 of its maximum HP, rounded down (but not less than 1 HP), at the end of each turn. Poison and Steel types can’t become poisoned. Poison has no effect outside of battle, unlike in games before Pokémon Black Version and Pokémon White Version.
Being badly poisoned differs from normal poisoning in the HP loss method during battle. When a Pokémon becomes badly poisoned or a badly poisoned Pokémon enters the battle, a variable, T, is set to 0 for that Pokémon. At the end of each turn, if the Pokémon is badly poisoned, T rises by 1 (up to a maximum of 15) and the Pokémon loses its maximum HP, divided by 16 and multiplied by T, but not less than 1 HP. (This HP loss happens instead of the HP loss for regular poisoning.) A badly poisoned Pokémon will remain badly poisoned if it leaves the battle and then enters the battle again in the same battle; however, it will become normally poisoned after the battle ends.
Unless otherwise noted, poison includes being normally poisoned and badly poisoned.
Paralysis (PAR)
If a Pokémon is paralyzed, its Speed is multiplied by 1/4 (see Priority ) and there is a 1/4 chance that it will be unable to attack during its attack segment. Ground types can’t become paralyzed by Electric type attacks.
Sleep (SLP)
When a Pokémon falls asleep or when a sleeping Pokémon enters the battle for the first time in a battle, it receives a sleep count of 2 to 4. At the beginning of the Pokémon’s attack segment, its sleep count is reduced by 1, and then it wakes up if the sleep count is 0 or less. A sleeping Pokémon’s sleep count will be reset to the determined sleep count if it leaves the battle and then enters the battle again in the same battle; however, the sleep count is lost after the battle ends, but the Pokémon will remain asleep.
Frozen (FRZ)
If a Pokémon is frozen, it can’t attack during its attack segment. Ice types can’t become frozen. At the beginning of the Pokémon’s attack segment, it will thaw out at a 20% chance. If the Pokémon is damaged by a Fire-type attack against that Pokémon by another Pokémon, it thaws out.
Confusion
When a Pokémon becomes confused, it receives a count of 2 to 5. At the beginning of the Pokémon’s attack segment, this count is reduced by 1, then if it is greater than 0, there is a 50% chance that the Pokémon will deal damage to itself rather than use an attack. The self-inflicted confusion attack is a physical attack, has a power of 40, has no type , can’t be a critical hit, and ignores the effects of Helping Hand, Huge Power, Hustle, Pure Power, and Reflect. Confusion is removed from the Pokémon when it leaves the battle (except Baton Pass).
Flinch
After a Pokémon uses a move that makes the target flinch in the same turn, the target can flinch when the beginning of its attack segment comes and thus skip its attack this turn. Effects that cause a Pokémon to flinch set a flag on that Pokémon. If the flag is set as the Pokémon begins its attack segment, it will flinch. This flag is cleared at the beginning of a Pokémon’s attack segment and at the end of each turn.