Pokémon Red and Green were originally released for the Game Boy in Japan.
Game Freak developed the role-playing games, and Nintendo published them. Their handheld format made collecting, training, battling, and trading Pokémon portable experiences. Trading was supported through the Game Link Cable, which connected two compatible Game Boy systems.
The Japanese releases were called Pocket Monsters Red and Green. Outside Japan, the games were localized as Pokémon Red and Blue, because the international version was based on the Japanese Blue release rather than simply using the original Green version. Pokémon Yellow later offered an enhanced version inspired partly by the television anime.
The Game Boy’s monochrome display and technical limitations shaped the first generation’s presentation, but they did not prevent the games from establishing the franchise’s core systems. The games were later remade for Game Boy Advance as Pokémon FireRed and LeafGreen, while the originals were rereleased on the Nintendo 3DS Virtual Console in 2016.