Which Pokémon games introduced Pokémon breeding?

Pokémon Gold and Silver introduced Pokémon breeding to the main series.

The games added the Pokémon Day Care system’s breeding mechanic, allowing compatible Pokémon left together to produce an Egg. After an Egg was obtained, carrying it while walking eventually caused it to hatch into a Pokémon. This created a new way to obtain Pokémon and plan moves, abilities, and inherited traits.

Breeding became especially associated with Ditto, which can pair with many Pokémon species. However, compatibility depends on Egg Groups, and some Pokémon cannot breed at all. Legendary Pokémon generally cannot produce Eggs, while many baby Pokémon require special conditions or an Incense item in later games.

Gold and Silver also introduced Pokémon Eggs through the story surrounding the mystery Egg, but story-given Eggs and player-controlled breeding are separate features. The breeding system became a central part of later competitive training and collection, making it one of Generation II’s most influential additions.