Pokémon Red and Blue were the game pair first released internationally after Japan’s Pocket Monsters Red and Green.
Game Freak and Nintendo launched Pocket Monsters Red and Green for the Game Boy in Japan on February 27, 1996. For international markets, the games were based largely on the updated Japanese Blue version, but they were presented as Pokémon Red Version and Pokémon Blue Version.
North America received Pokémon Red and Blue on September 28, 1998, while Europe received them on October 5, 1999. The original Japanese Green version was not released internationally at that time, making Red and Blue the worldwide introduction to the core Pokémon games.
The two versions shared the same main adventure but had different Pokémon available in each cartridge. Players could connect two Game Boy systems with a Game Link Cable to trade version-exclusive Pokémon and battle, an important feature that helped define the series.