Core series/Classification/Pokémon

Most generations introduce that evolve into or from previously released Pokémon. Legendary Pokémon with myths specific to the region are almost always included, and frequently appear in duos and trios.

In all generations, there are some Pokémon that cannot be encountered until after the undefined enters the Hall of Fame. These may be legendary Pokémon, such as, or simply Pokémon that are not part of the game's regional Pokédex.

Before the release of a new generation, new Pokémon are often used to promote the new by including them in the  or in spin-off games.