You select a paragon path at 11th level. You gain access to two or more paragon path features at 11th level, including a paragon path feature that let’s you broaden the use of an action point with an additional benefit. You also gain another paragon path feature at 16th level. In addition, selecting a paragon path gives you access to one encounter power at 11th, one utility power at 12th, and a daily power at 20th. Alternatively if you wish, you can also select powers from a second class in place of a paragon path.
But adopting a paragon path doesn’t mean you stop advancing in your class. All the powers and features you gain from your paragon path come in addition to your class powers and features, not instead of them. You don’t stop being a cleric when you become a radiant servant. Instead, you gain new capabilities that extend, enhance, and complement the abilities of your class.
Paragon paths also broaden the use of action points in different ways. Each paragon path features a different, extra capability that characters can unlock by spending action points. So, once you pick your paragon path, you can still spend an action point to take an extra action. But you’ll also have a new capability for action points that is unique to your path. Some of these capabilities come in addition to the extra action you get for spending an action point, some are used instead of getting an extra action.
When you reach 11th level, choose a paragon path. All paths have prerequisites, conditions you have to fulfill before you can adopt that path.