Pokemon games in the mainline series often introduce entirely new features and gimmicks or improve on other ones added in past games, at times even reshaping the concept of it, such as with Pokemon Scarlet and Violet's regional fakes compared to regional forms. There were also times when the series made exclusive decisions and features for a single game and then never again, with an example being Pokemon Yellow's fixed Electric-type starter rather than one players can choose from a selection of three, all within the Grass/Fire/Water trifecta. Gen 3 games, both in the form of Pokemon Ruby and Sapphire and later Pokemon Emerald, also have an exclusive feature that never came back - but it should.