To customize the Grid, more specifically to max out stats.
FF 12 use license broad, when u kill a monster, u will get "LP", u will ned a amount of LP to learn certains skill, ability ,weapon equip, armor equip, ring equip and etc.
like if u want equip muramasa, then u must get the license to equip muramasa 1st, otherwise u can't equip it
if u want to learn fire, u must get the license 1st, and then got magic shop to buy the "rod" to learn it
about lving system.... just like on9 game, kill 1 monster get exp then lv up~, the exp will divide to 3 if the party got 3 member.....
max party is 3 ppl, sometimes got guest inside the party will be 4 ppl