Japan’s 1998 game Pocket Monsters Stadium allowed 40 Pokémon species in gameplay.
Developed and published by Nintendo for the Nintendo 64, Pocket Monsters Stadium was the first Stadium title. It adapted the battle system from Pokémon Red and Green and used 3D models and animations for its selected Pokémon.
The game was originally intended for Nintendo’s 64DD peripheral, but it was ultimately released on a standard Nintendo 64 cartridge. Its limited roster was partly a result of development constraints. Players could also connect the game to the Game Boy titles through the bundled Transfer Pak.
The game was not released outside Japan. An expanded follow-up was released internationally as Pokémon Stadium, although it was known as Pokémon Stadium 2 in Japan. That later title supported all 151 Pokémon from the first-generation Game Boy games, making the two games easy to mix up.