The protagonists tend to be special to some degree because by the end of the game they're expected to Kill God. But the "special"-ness is as often a product of the intro as some inherited bloodline. Look at the Persona series, for instance. Or Chrono Trigger or Earthbound or Mario. As often as not, the protagonist is just some everyman who gets hit in the head with the Magic Rock of Destiny and finds himself on an unexpected adventure.
The protagonists tend to be special to some degree because by the end of the game they're expected to Kill God. But the "special"-ness is as often a product of the intro as some inherited bloodline. Look at the Persona series, for instance. Or Chrono Trigger or Earthbound or Mario. As often as not, the protagonist is just some everyman who gets hit in the head with the Magic Rock of Destiny and finds himself on an unexpected adventure.