Though you look vulnerable, that wobble is part of your cunning plan.
Prerequisite: Catch Off-Guard
Benefit: As a standard action, you may make a Bluff check to appear to have made a misstep and be off-balance. This is opposed by the Sense Motive check of any opponent observing you. If you win this check, the opponent believes you have lost your Dexterity bonus to your AC. Not only is this not the case, any foe fooled by this Bluff that attacks you in the next round and misses also provokes an attack of opportunity from you.
Adventurer’s Handbook: Genius Guide Volume 1