Pokémon Black Version and Pokémon White Version - Failure
An attack "fails" if it does none of its effect when used, unless noted otherwise, except if the attack description states that the attack "does nothing" as its effect.
An attack that changes stat stages without necessarily lowering or raising them, such as Psych Up and Haze, won’t fail if the change results in the same stat stages as before, unless noted otherwise.
An attack that can’t be used because it has no target is considered to "fail", but not considered to be "prevented from being used".