 A few moves, such as Splash, does nothing whatsoever except when used as a Z-Move.Once per battle, if a Pokémon holds a Z-Crystal, a powerful object obtained from completing island trials, it can use an upgraded version of one of its moves, called a Z-Move.Z-Moves based on attacking moves tend to have much higher power than normal; those based on status moves usually incur a benefit on the user before executing the move.