Attacks Of Opportunity
Occasionally an opponent missteps during combat or flees in terror. These are the moments in which you can capitalize and press the attack.
You threaten an area around you equal to 5 ft in any direction. You only provoke with weapons you are proficient with or hostile touch spells.
Most creatures of Medium or smaller size have a reach of only 5 feet. This means you can only make attacks against creatures within 5 feet of you. Some weapons have the Reach quality which allow you to extend your reach by 5 feet, but you no longer threaten within your original 5 ft. In addition, most creatures larger than Medium have a natural reach of 10 feet or more.
Provoking an Attack of Opportunity
There are several actions that can provoke an attack of opportunity, the most common of which is movement.
Moving out of a threatened square usually provokes an attack of opportunity from the threatening opponent. Taking a 5 ft step or using the withdraw action do not provoke from their movement.
Other Actions that Provoke
Some actions, when performed in a threatened square, provoke attacks of opportunity Actions in Combat notes many of the actions that provoke attacks of opportunity.
Making an Attack of Opportunity
An attack of opportunity is a reaction that allows you to make a single melee strike against an opponent who has provoked. You don’t have to make an attack of opportunity if you don’t want to. This attack incurs the multiple attack penalty from any other strikes you have made during the round.
When an attack of opportunity occurs it interrupts the normal flow of combat and is resolved before the provoking action.