I'm curious how other groups handle the following situations, and if there are any official rules I'm missing about it.
Question: If a character is within the threatened area of another creature, assuming no other prior knowledge of the creature - do they know it?
Example 1: A giant rolls up 10ft away from a wizard. The giant has 10ft reach. Assuming he has not seen the reach of the giant yet, does the wizard "Feel threatened" enough to know he needs to cast defensively?
Example 2: A fighter (without Combat Reflexes) moves up and trips a Wizard. The Wizard provokes an AoO from the fighter while standing. Does the Wizard "feel threatened" even though the fighter has no remaining AoO's? Does he know he can cast spells safely?
Example 3: A tenticle monster with Combat Reflexes and a huge reach is in range of a party of heroes. One of the heroes provokes an AoO from movement. Do the other heroes "Feel Threatened" if the creature can still take more AoO's? Do they know they need to Acrobatics to move safely?
My assumption is that during a battle a character always "Feels threatened". Anything else they wish to assume about the capabilities of the opponent is their choice.