after final fantasy 6, the system in leveling has never been the same twice. Though it's become more decided how limit breaks work *seems like they've been extinguished in FF:chronicles and beyond: someone please correct me if i'm wrong*
Just a lil brief on the level systems that I do know *just for anyone who doesn't* lol:
Final Fantasy 1: Go buy your magic and fight for stats
Final Fantasy 4: Levels for stats and magics occasionally beat on a special enemy for a special summon
Final Fantasy 6: Espers for magic and additional stats at level, main stats through basic leveling - "limit break" introduced as critical attack
Final Fantasy 7: Equiped materia for spells and abilities slightly alter stats, levels for stats- limit breaks based on damage and usage
Final Fantasy 8: Junction system for stats, leveling barley helps, junction for magic- limit breaks based on low health used endlessly
Final Fantasy 9: Level for stats, equip armors and weapons to learn abilities- *forgot what limit was called* based on taking in damage
Final Fantasy 10: Sphere grid for stats and magics- overdrive based on differing factors
Final Fantasy: Crystal Cronicles: Stats based on aquiring artifacts at the end of a level and spells also- no limit break that i kno of