the battle system is really simple. you just set the attacks and press triangle when youre done, or waste all the atb gauge to make a bigger combo. to change classes press the L1 button (dont know about xbox) and set the class you want. you use no MP, so always have a mage in your team. and you automaticaly heal after each battle. so you dont have to worry about healing during the battle if you have lower health. everyone gains xp, so you dont have to train everyone. you can change your team pretty often. just like in FF II, once you upgrade a weapon you should stick with it. because it costs a lot to upgrade weapons. or just wait until the end of the game to upgrade the better weapons. hope i helped