You can burst out at a foe and strike before it realizes what you are doing.
Prerequisite: Stealth as class skill.
Benefit: When you are unobserved, you make take a full round action to charge a single target that is unaware of you. You make a Stealth check, opposed by your opponent’s Perception check. (You may make this check even if in bright light and lacking cover.) If your check succeeds, your target is unaware of you until after the attack at the end of your charge. (Creatures other than your target may notice you normally.) The target is denied its Dexterity bonus against the attack made at the end of your charge.
Adventurer’s Handbook: Genius Guide Volume 1