Which Pokémon games were the first in the main series to launch worldwide simultaneously?

Pokémon X and Y were the first main-series Pokémon games to launch worldwide simultaneously. They were released for Nintendo 3DS on October 12, 2013.

Before X and Y, Pokémon games typically reached Japan first, followed by staggered releases in North America, Europe, and other regions. The worldwide launch reduced the wait between markets and let players around the world begin the sixth generation at nearly the same time.

X and Y introduced the Kalos region, 72 new Pokémon species, the Fairy type, character customization, and Mega Evolution. They also moved the main series from sprite-based presentation to fully polygonal 3D graphics.

The games are sometimes confused with Pokémon Sun and Moon because both were major global releases on Nintendo 3DS. However, X and Y hold the specific distinction of being the first main-series titles with a simultaneous worldwide release.