Opportunity Actions may only be used when you are granted an Opportunity from an opponent. When you choose to take an Opportunity Action, your action is resolved before the Action that granted the Opportunity (effectively interrupting the action that granted the Opportunity). This means that sometimes your Opportunity Action will impact the result of the action that granted the Opportunity (disrupting it or changing its effect). There are no Recovery Times for Opportunity Actions.
You are limited to taking a maximum of 3 Opportunity Actions per round. You cannot use an Opportunity Action during your turn. You may only use a single action or ability in response to an Opportunity (or other triggering event).
The following actions grant an opportunity:
- Move through or out of an area a creature Threatens without shifting.
- Making an attack or using a power the provokes an opportunity (indicated by [P] in the effect or attack line of the power).
- Utilizing an action that otherwise states that it grants an opportunity.
- At the GM's discretion, any action that causes you to stop paying attention to an opponent while within their threat can grant an opportunity (ex. making a Heal check on a 3rd party, pulling a weapon from a pack or other stowed location, etc).