Which console was the first Pokémon X and Y main series game designed for?

Pokémon X and Y were the first main-series Pokémon games designed for the Nintendo 3DS.

Released in 2013, X and Y were Generation VI role-playing games developed by Game Freak. They shifted the main series from sprite-based presentation to fully rendered polygonal 3D graphics, including more dynamic battles and a three-dimensional overworld.

The games introduced the Kalos region, the Fairy type, Mega Evolution, character customization, Sky Battles, and Horde Encounters. They also marked the first worldwide simultaneous release for a main-series Pokémon pair, with the games launching internationally on October 12, 2013.

Pokémon games had appeared on earlier Nintendo handhelds, including the original Game Boy, Game Boy Color, Game Boy Advance, and Nintendo DS. The Nintendo 3DS identification therefore refers specifically to X and Y’s original platform.