Core series: Difference between revisions

When a [[generation]] of [[Pokémon games]] begins, a pair of games is always released. These paired versions feature virtually the same storyline as each other, but the [[Game-exclusive Pokémon|available Pokémon]] differ, and some other elements are usually slightly different. This encourages [[Trade|trading]], as it is required in order to complete the [[regional Pokédex]].

Most generations feature an "upper version"<ref>[https://www.youtube.com/watch?v=3CldWM5ornc Nintendo UK YouTube]: Pokémon Ultra Sun & Pokémon Ultra Moon Introduction – Episode 4 – A new Pokémon adventure awaits</ref> title, a follow-up game or pair of games released after the first games of the generation that takes place in the same [[region]] with added features. These sister games typically both share and lack certain regional {{OBP|Pokémon|species}} that were available in one or both of the original paired versions; thus, a {{player}} of an upper version must link together with the original pair to complete the regional Pokédex as well. On the contrary, upper versions typically contain certain Pokémon from different regions that are unavailable in the original pair, thus being more helpful in completing the [[National Pokédex]]. Until [[Generation VII]], only a single "third version" following an original pair was ever released at a time; [[Pokémon Ultra Sun and Ultra Moon]] were the first sister games to be released as a pair. Unlike other generations, [[Generation V]] opted for a sequel story instead, and [[Generation VI]] entirely forewent follow-up games set in the same region.