What device allowed players to trade Pokémon between the original Game Boy games?

The Game Link Cable allowed players to trade Pokémon between the original Game Boy games.

The cable connected two Game Boy systems, letting players battle and exchange Pokémon. This feature was central to Pokémon’s design because no single version contained every one of the original 151 species.

Nintendo released different versions with version-exclusive Pokémon, encouraging players to connect with friends who owned another cartridge. For example, completing the Pokédex required trading between Pokémon Red and Blue, or between the corresponding Japanese versions.

The trading system grew from Satoshi Tajiri’s idea that Pokémon should move between players through the Game Boy’s communication port. What began as a hardware connection became one of the franchise’s defining social features. Later Pokémon games replaced the original cable with wireless communication, online services, and other transfer systems.