You spend energy to improve your dodge chance. Each successful dodge consumes more energy, so the stance can only be sustained for a limited time.
On success, the target gains 31 dodge incoming attack for 300 rounds.
Abilities belong to classes and can be used by players and NPCs. Most abilities must be learned first, and some become stronger when you invest points in them. Ability scrolls let you use an ability a limited number of times, even if you have not learned it.