Epic-Level Play

Profiency bonus

Continues to advance:

Legendary (Strength/Dexterity/etc): You gain +4 to one ability modifier (+8 in the old-school stat system). Stackable once per 10 epic levels.
Continued Studies: You gain one level of a class you didn't already have 20 levels in. Does not grant new skills, Hit Points, saves, etc, but does grant other class abilities (such as spell knowledge).
Legendary Action: Choose one action you can take (such as attacking, using a specific maneuver or spell, etc) that is integral to your normal play style. You may now use this action as a legendary action once per round, only after an enemy takes their turn. You may take this boon multiple times, adding additional legendary actions, but you can still take only one legendary action per round.
Strong Soul: Your magical essence is expanded. You may now attuned one additional magic item.