Why did Pokémon FireRed and LeafGreen come with a wireless adapter in the box?

The Game Boy Advance Wireless Adapter was Nintendo's new link-cable replacement, a small unit that clips to the handheld and lets nearby players trade and battle without wires. FireRed and LeafGreen were its showcase software, built around the Union Room, a wireless lobby where players gather, trade and battle by walking up to each other in the game.

A showcase needs an installed base, so Nintendo made one: every launch copy of FireRed and LeafGreen, in Japan and in North America and Europe, came with the adapter bundled in the box at no separate purchase. Contemporary listings and reviews record the bundle as standard, and Bulbapedia notes the adapter was no longer bundled in later copies, marking the campaign as a launch-era seeding of the hardware.

The strategy is a familiar Nintendo pattern, new connectivity proven by Pokémon, but the object it leaves behind is distinctive: a bigger box, an adapter most owners used a handful of times, and a complete-in-box copy whose completeness is judged partly by a piece of grey plastic.

The adapter went on to serve other games, including Emerald, but it belongs to these remakes in the public mind, the moment Pokémon trading first cut the cord.