Posted July 13, 2015
Nephilim88: And remember that some advanced skills require a specific amount of points already spent in that category... however, just to clear things up a bit (I have the impression that you are a bit confused, but I may be wrong): skills in white are already unlocked, if they have a level can be upgraded, and to activate/equip them you have to put it in a tree slot; skills in grey are not unlocked yet and you can spend your skill points to unlock them, then you have to activate/equip them.
I am learning as I play the game. Just discovered that there are more than one skill tree and I am about to move on to Velen.