A natural roll is the actual number appearing on the die, not the modified result obtained by adding bonuses or subtracting penalties.
Example[edit | edit source]
A d20 is used to see if a character succesfully hits an opponent. He adds his base attack bonus to his attack roll along with other modifiers (such as his strength modifier). If a 20 is the die's roll value, this is a "natural 20" even if the modifiers results in a different number afterwards.