A status condition is a lasting ailment inflicted in battle, covering the major conditions burn, paralysis, poison, sleep, and freeze, plus volatile conditions such as confusion that end on switching. Major conditions persist after battle in most games and usually block each other.
The five major conditions each attack a different part of a Pokémon. Burn halves the damage of the burned Pokémon's physical moves and chips its HP each turn, except in Generation I and II where the rules differed in detail. Paralysis cuts Speed, to one quarter in Generations I to VI and to one half from Generation VII onward, and gives a chance to lose the turn entirely. Poison drains HP, badly poisoned status from Toxic drains more each turn, sleep removes turns until the Pokémon wakes, and freeze removes turns until it thaws, often by being hit by a Fire move.
A Pokémon can hold only one major condition at a time, which players use defensively: a burned wall cannot also be put to sleep. Types grant immunities too. Fire types cannot be burned, Electric types cannot be paralyzed since Generation VI, Poison and Steel types cannot be poisoned, and Ice types cannot be frozen since Generation IX.
Volatile conditions such as confusion, infatuation, and trapping effects sit on top of a major condition but vanish when the Pokémon switches out. Status is often the real plan behind a defensive team, because chipping a faster opponent down and cutting its Speed changes matchups that raw damage cannot.
In play"Burn him first, then his physical attacks will barely hurt for the rest of the fight."