Fairy Lock prevents all Pokémon on the field from switching out or fleeing during their next turn. Ghost-type Pokémon are unaffected.
Fairy Lock does not prevent the effects of moves or items that force the target to switch, such as Dragon Tail, Whirlwind, Eject Button, or Red Card. If a Pokémon that's on the field when Fairy Lock is used goes on to faint later in the same turn, the Pokémon that replaces it will still be unable to switch out in the following turn.
If powered up by a Fairium Z into Z-Fairy Lock, the user's Defense stat rises by one stage.
In version 1.1.0 of Pokémon Sword and Shield only, using Fairy Lock while animations were enabled caused the console to crash. In multiplayer battles, where animations are mandatory, both players' consoles crashed. This bug did not occur in earlier versions and was fixed in version 1.1.1.