Though graphics and programming tricks evolve and improve, the basic structure of any RPG goes back to pencil-and-paper games we were playing on the tabletop, a decade or so before
Final Fantasy III saw its first release.
Final Fantasy III doesn't pull any punches with the long and deep storyline, wide cast of characters, and open-world exploration. Games that are now considered "open world" are beloved by gamers because they offer such a wide range of choice.
Final Fantasy III dictates a few choices, namely that you'll be grinding for hours to level up and prepare for tougher enemies and boss battles. The difference between a mediocre and a great RPG is that the latter makes you feel good about the grind.
The storyline feels (in hindsight only) pulled from a chapter of the more recent Crystal Chronicles lineage of Final Fantasy lore, in that it revolves around a company of unlikely heroes united by a prophecy delivered through a powerful crystal. The members of your party are defined more by their personalities than class, because this game was the beginning of the series' job system. Rather than each character specializing in one role, you mix and match as characters gain experience, developing them along whatever line you choose. This makes for some great battle combinations and keeps players on their toes, but mostly just keeps the battles interesting. Along with this quick-change system comes a raft of special abilities, magic, and equipment that will vary based on your current job. No wonder this approach won acclaim; how many other games from this period could you find where two players could design two totally different experiences, based on freedom of choice?