Im replaying this for the first time since i first played it and Im not having any problems. Just more of a curious question.
When you gain exp and JP in a battle. What determines where the exp goes? I find myself getting JP and exp in job classes that im not using anything from.
Lets say i take a white mage with black mage seconday into battle. After the battle i look and noticed that chemist has gone up a level and squire has also gotton JP (For example).
How in the hell does it determine where the exp goes?
Exp works like it does in RPGs traditionally; You become more powerful as you gain levels with it.
Character levels and job levels are not the same.
Jobs other than the one your character uses gain JP because when you use a job, you gain jp, 1/8 of that jp goes to other characters using other jobs. So, if you wanted to master a Knight REALLY FAST, you’d make everyone a knight and watch how you get lots of Knight JP.
Thanks for the info. Got another question.
What happens when you max out your class level and you gain exp while using that class? Does the exp just dissapear or does it give a larger portion to your other classes?
If you mean JP, if you have a class mastered, the JP just disappears, yes (besides for the 1/8 of it that goes to your other party members). EXP, of course, has nothing to do with your class and will keep rising until you reach level 99. 
I dont mean JP. I have multiple Jobs that are level 8 and will not gain any other levels, but i still gain JP in it and can still gain skills.
I meant the exp that raises the job level. Does that get wasted?
JP IS what raises job levels. Exp is character level only and only goes up to 100 before it rolls to the next level. JP goes up to 9999 stored and I forget the amount of JP needed to raise a job level, but usually you’ll be level 8 in a job before mastering it.
So to answer your question. No it doesnt get wasted if you can still spend it. JP is only wasted if all your characters currently fighting are masters in that class.
Why bother even having job levels? I have level 8 in many of my jobs but have by no means gotton all the skills. Just seems like a real wierd ass system heh.
I was changing jobs at level 8 because i thought things were getting wasted. So even if i have a level 8 job it doesnt hurt to stay in it as long as I still have skills to get?
You are correct sir. If you hit level 8 but have more skills to get, by all means stay with the job till you get the skills you want.
Rock on - thanks all. Im sure all this was explained in the manual but I lost it long ago during one of my many moves heh.
The point of job levels is that later jobs only become available when you’ve reached particular levels in specific earlier jobs.