The gameplay of the Pokémon series of role-playing video games involves the capture and training of a variety of fictional creatures called "Pokémon" and using them to battle other trainers. Every generation of games follows this concept by introducing new Pokémon, items, and gameplay concepts. Some of the general concepts were featured elsewhere before being introduced in the games; double battles appeared in the anime long before appearing in the games, and Pokémon abilities are similar to the Pokémon Powers introduced in the "Pokémon Trading Card Game".