Despite each major new release being numbered, Final Fantasy is a disparate series of games, each with their own characters and stories to tell. The only thing that carries over from title to title are certain enemies, character names, and the names of spells. Each new game introduces players to a completely unique world that is home to its own conflicts, locations, and rules. You can pick up any title in the franchise – except for direct sequels to previous titles – and follow along easily because you, like everyone else playing the game, is starting out at the beginning.
Final Fantasy VII is still one of the most beloved titles in the series. But compare it to the most recent game in the franchise, Final Fantasy XV, and the differences are night and day. FF VII is a turn-based RPG set in a dystopian future where an evil corporation is draining the planet of one of its most important energy sources. FF XV, on the other hand, is set in a fantastical world that is still very reminiscent of reality where two rival kingdoms clash for control of the land. Both are completely different games but the small details that connect them still brings back fans of the series. This approach also ensures that the formula never grows stale because it is constantly reinventing itself with each iteration.