SNEAK ATTACK
Usage: Passive
When a thief finds an opening, their attacks will receive bonus [sneak] damage. This added damage increases as your thief level increases, including a prestige class with a thief base. You are able to get the sneak attack bonus when your opponent is blind, paralyzed, bound, or attacking another target that round. Be aware that there are many abilities that can reduce or outright cancel this bonus damage.
See also: thief, stab, prestige class