Pur, come dice Dusdan, non utilizzando la cosa come da manuale, in realtà la regola mi sembra abbastanza chiara.
Flat-Footed: At the start of a battle, before you have had a chance to act (specifically, before your first regular turn in the initiative order), you are flat-footed. You can’t use your Dexterity bonus to AC (if any) while flat-footed. Barbarians and rogues have the uncanny dodge extraordinary ability, which allows them to avoid losing their Dexterity bonus to AC due to being flat-footed. A flat-footed character can’t make attacks of opportunity.