If I for instance get a surprise round and do not have anything to attack... Can I proclaim I fight defensively? (counting for AoO and AC when attacked)
Can I still use my sole action as a move action then? Or just proclaim I fight defensively as a Standard Action?
Fighting Defensively is the equivalent of Power Attack; it must be triggered when you attack or are going to attack (such as with a Readied Action), and you can't take such activity until you commit to the action being taken.