It’s a deep, engaging system, and one later found in Final Fantasy V, Final Fantasy Tactics, Final Fantasy X-2, Final Fantasy XII, and other franchise titles. This marks the first appearance of Summoners, Dark Knights, Dragoons and others - but also it just leads to a pretty exciting and fun system for players of FF3 to play with. The influence of the FF3 Jobs can’t be overstated.
It's the core of the experience in Final Fantasy III, with jobs defining the abilities you have, base stats, and the equipment you can use. Jobs and classes of course appeared in the previous games in a manner of speaking, but at the core of the combat and strategy of FF3 is the player’s ability to unlock, play as and switch between a wide variety of jobs - all of which have unique abilities. The remaining game’s contribution? Of course, it’s the Final Fantasy III Job classes system. FF1 lays the groundwork for much of the series in general.
Each of the first three FF games introduces something that’d become fundamental to the rest of the series as we know it today.