think it works like this: About new skills that you are offered: You are offered wisdom at lvl 6 if not earlier. Earlier than lvl 6 the chance of getting wisdom is the same as for other skills (means it depends on the number each heroclass has in wisdom, for example knights 3, barbarians 2). If you do not choose wisdom it will be offered again 6 levels later if not earlier. You are offered a magic skill at lvl 4 if not earlier. Which of the magic skills you will be offered depends on your numbers in the diffrent magic skills). Earlier than lvl 4 the chance of getting magic is the same as for other skills. If you do not choose the magic skill offered you will be offered magic again 4 levels later if not earlier. If you choose the first magic skill offered I dont know when you can be sure to be offered magic again but I have had games where it was as late as 12-13 levels later. About improving skills you allready have: I have heard it mentioned that you have a bigger chance of being offered adv or exp in skills where you have high numbers compared to skills where you have lower numbers but I dont know exactly how it works