Your quick movements increase dexterity, make attacks easier to dodge, and provide some damage reduction.
On success, the target gains 3 dexterity stat for 40 rounds and gains 5 dodge incoming attack for 40 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.