Pocket Monsters Stadium, the first Pokémon Stadium game, was released in Japan on August 1, 1998.
The Nintendo 64 game was developed and published by Nintendo. It brought Pokémon battles into a 3D arena and connected with the Game Boy Pokémon games through the Transfer Pak. Unlike the later international Pokémon Stadium, this first title was released only in Japan.
Technical limits shaped the game. Although the original Game Boy games featured 151 Pokémon, Pocket Monsters Stadium supported only 40 Pokémon in its battles. Many of those choices reflected official tournament use, while others represented different Pokémon types. The game also included compatibility features for Pokémon Red, Green, and Blue.
The naming history can be confusing. Japan later received a larger follow-up called Pokémon Stadium 2, while that follow-up was released internationally as Pokémon Stadium. Therefore, the Western title Pokémon Stadium usually refers to the 1999 Japanese release and the 2000 overseas releases, not the August 1998 original.