Pokémon Sun (ポケットモンスターサン, Poketto Monsutā San) is a role-playing video game developed by Game Freak and published by Nintendo for the Nintendo 3DS. It is the first installment in the seventh generation of the Pokémon series and is the first installment in the series to be released on the Nintendo 3DS. The game is set in the Alola region, based on the real-life islands of Hawaii. The game follows the same basic formula as its predecessors, in which the player must travel around the region, catching and training Pokémon to compete against other trainers. The game introduces a new battle system, called the Battle Royal, in which four players can battle each other at the same time. The game also introduces new Pokémon forms, called Alola Forms, which are exclusive to the Alola region. The game also features an improved online battle system and improved graphics. Pokémon Sun is the third-best-selling 3DS game of all time, behind Mario Kart 7 and Pokémon X and Y.