The Mossdeep City Gym is the official Gym of Mossdeep City. The Gym Leaders here are Tate and Liza and they both use Psychic-type Pokémon. In Ruby and Sapphire the Gym Trainers were all Psychics, with Tate and Liza being the only Double Battlers. In Emerald, since Double Battles were more common, The Mossdeep Gym managed to get an overhaul and endorse Double Battles when the player managed to push a switch.