Aptitude represents your exposed potential. A higher level of Aptitude means that a higher hidden potential in your character has been brought forth. It's also your ability to further learn and adapt to every situation given at you, be it good, bad or worse.
Aptitude does not govern any direct combat skill but the capacity to learn more, combat or not.
- Increases EXP and Crafting EXP by 1% per 1 point.
- Every 6 points in Aptitude increases every other stats (except Aptitude) by 1.
Having 36, 42* and 49* APT is a good idea, if not mandatory. It also gives a valuable EXP boost, making it one of the most important stats to have on early levels.
* (Can also be 43/50, depending on your race. Just spend enough points until the bonus stats are gained/shown.)