Your finely-tuned ability to read others prevents them from getting the drop on you.
Prerequisite: Sense Motive 3 ranks.
Benefit: As long as you are aware of a creature’s presence, it is difficult for that creature to attack you by surprise. If they initiate a combat and would normally gain a surprise round (such as, for example, by attempting to stab you by surprise in the middle of a pleasant conversation) you may automatically make a special Sense Motive check as a free action (DC 20). If you succeed, you get a hunch that something is wrong, and can act in the surprise round as well. If this would cause all combatants to act in the surprise round, there is instead no surprise round. This feat offers no protection against surprise attacks from enemies you are not aware of (such as those sneaking up behind you, for example).
http://www.necromancers-online.com/. Copyright 2010-2012 Necromancers of the Northwest, LLC