Originally Posted by DarkMaverick
When you hit level 100 on a skill tree you get a mastery point to apply to a skill in that tree. To see what a skill does when mastered click the little bubble marked 'Sort Booste'.
Unfortunately, not all skills have masteries just yet. I can't make an assumptions yet. ;x
Also, updated the guide with more STR-tree stuff and a section for my beacons.