Yep, I forgot to write in my prev post that points into the respective school lower the AP cost of spells.
e.g. If i made a man-at-arms char and level to max
then put 1 point into expert marksman I can learn the highest level marksman skill, no problem.
BUT it will do almost no damage/heal and it will cost probably more AP than I have.
So:
int/str/dex increase "potency" of spells (be it damage or heals)
schools increase amount of spells you can carry and lower their AP
The default Hotkey for your spells is "K".
You can unlearn skills there if you have no free slot and the new one is better.
BUT: any unlearned skill is GONE, you have to find another skillbook to activate it again.
