When you reach level 20 a Skill points shield will appear and an add will start flashing above your avatar tab.
When you press the Skill points shield a new window will open.
For every level over level 20 you get 5 potential skill points per level to allocate to the 5 characteristics with the plus sign next to them.
There are 5 categories that the potential can be added to by all classes. Below is a Breakdown of what each class gets from each category.
There are two ways that the Stats area below the Characteristics (highlighted) improve.
The first way is by the Characteristics themselves.
The second way is by Levelling up.
I hope you all enjoy the game as much as I do (Happy Gaming)