Your words are more frightening than your weapon.
Prerequisite: Cha 15.
When you catch an enemy off-guard, you can take him hostage. Your blade remains pressed against his throat, a flick of your wrist away from a lethal cut. In melee combat, you can attempt to throat threat a flat-footed opponent as a standard action. Because your opponent must be flat-footed, this does not provoke an attack of opportunity. You cannot be threatened by any other foes when you initiate the throat threat and you must be wielding a slashing or piercing melee weapon (typically a dagger but not limited to it). Your target immediately becomes aware of you when you attempt to throat threat.
If successful, both you and the target gain the grappled condition. Although both creatures have the grappled condition, you can, as the creature that initiated the throat threat, release the throat threat as a free action, removing the condition from both you and the target. If you do not release the throat threat, you must continue to make a check each round, as a standard action, to maintain the hold. If your target does not break the throat threat, you get a +5 circumstance bonus on throat threat checks made against the same target in subsequent rounds. Your target remains flatfooted against you for as long as you maintain the throat threat. Unlike a grapple, while you throat threat a creature you can only perform one other action, a vital strike.
While maintaining a throat threat, you may make a single devastating attack, known as a vital strike, as an immediate action if your target attempts any action that you are aware of, or if any of your target’s allies provoke an attack of opportunity from you or enter your threatened area. A vital strike automatically hits and scores a critical hit against your flat-footed opponent and your target must make a Fortitude save (DC equal to the damage dealt) or be stunned for one round. Your opponent may make a Stealth skill check to attempt an action without your noticing, including a move action that gets away from your throat threat, but you gain a +5 bonus on the opposed Perception check to notice. Creatures immune to critical hits are immune to throat threat. You can only throat threat a target your own size or one size category smaller than you. Creatures of a different type than you get a +5 circumstance bonus to their Fortitude save to resist being stunned.