Originally intended for the Nintendo 64DD, it was later developed into a standard console game after the add-on failed. The gameplay revolves around a 3D turn-based battling system using the 151 Pokémon from the Game Boy games Pokémon Red, Pokémon Blue, and Pokémon Yellow.
First released in Japan on April 30, 1999, it was later released as the first Stadium title in Western regions the following year, and is a sequel to the Japanese-only 1998 Nintendo 64 release Pocket Monsters Stadium. Pokémon Stadium, known in Japan as Pokémon Stadium 2, is a strategy video game developed and published by Nintendo for the Nintendo 64.