In the core series
If the Pokémon holding a Focus Band is hit by a damaging move that would cause it to faint, there is a ~12% (30/256) chance the Focus Band will activate and cause its holder to survive with 1 HP. Focus Band can allow the holder to survive Future Sight. It cannot activate as a result of self-inflicted confusion damage.
If Focus Band activates as a result of a multi-strike move, the holder does not faint from any of the strikes.
Generations III to IV
The Focus Band now has a 10% chance to activate. Focus Band now allows its holder to endure self-inflicted confusion damage.
Focus Band can allow the holder to survive Doom Desire.
Generation V onward
From Generation V on, Focus Band must trigger separately for each strike of a multi-strike move.
||May prevent fainting. (HOLD)
||A hold item that occasionally prevents fainting.
||An item to be held by a Pokémon. The holding Pokémon may endure an attack, leaving just 1 HP.
|An item to be held by a Pokémon. The holder may endure a potential KO attack, leaving it with just 1 HP.
In the anime
In the manga
In the TCG
In other languages