|Cast a spell
|Usually a standard action
|Draw a weapon
|Swift action or as part of a move action
|Use a consumable
|Pick up an item in [Melee] range
|Use combat maneuver
|Use extraordinary ability
|Use spell-like ability
|Use supernatural ability
Sometimes a creature in melee combat lets its guard down. In this case, nearby combatants can take advantage of the lapse in defense to gain free attacks. These free attacks are called attacks of opportunity.
You threaten all squares within [Melee] range, even when it is not your turn. An enemy that takes certain actions while in a threatened square provokes an attack of opportunity from you.
Provoking an Attack of Opportunity
Generally speaking, activating spells and spell-like abilities provokes attacks of opportunity, while activating extraordinary and supernatural abilities does not provoke attacks of opportunity unless they cause the user to move out of threatened squares. The following actions provoke attacks of opportunity when performed in threatened squares.
Moving out of a threatened square usually provokes an attack of opportunity from the threatening opponent. There are two common methods of avoiding such an attack: the 5 ft step and the Run action. Remember that movement caused by opponents (such as being [Blown away] by an Iron Magi's Howl of the North Wind) or other allies (becoming the target of a friendly tactician's dimensional swap) does not count as an action made by you, and thus would not provoke an attack of opportunity unless otherwise stated.
Performing a Distracting Act
Some actions, when performed in a threatened square, provoke attacks of opportunity as you divert your attention from the battle. Remember that even actions that normally provoke attacks of opportunity may have exceptions to this rule.
Making one or more ranged attacks provokes an attack of opportunity.
Making an Attack of Opportunity
An attack of opportunity does not count as an action, but effects that prevent you from taking actions or making attack rolls prevent you from making attacks of opportunity.