Natural 20

A Natural 20 is obtained when you roll 20 on the d20. The word natural means that no modifier (bonus or penalty) is taken into account to obtain 20 (for instance, if you roll 15 on the d20 and have a +5 to-hit bonus, it is not a natural 20, even though the modified to-hit roll is 20).

When rolling to hit an opponent, a natural 20 is always a critical threat.