Egg Groups are classifications that help determine whether two Pokémon can produce an Egg together. Many species belong to one or two groups, and compatible parents generally need at least one matching group unless Ditto is involved. Some Pokémon, including many legendary or baby Pokémon, are in the Undiscovered Egg Group and cannot breed. Egg Groups are separate from a Pokémon’s battle type; two Water-type Pokémon may still be incompatible if their Egg Groups do not match. Egg Group information is mainly relevant for breeding, inheriting moves, and planning competitive projects. It has no direct effect on ordinary battle damage.
