Criticals

When you roll a natural 20 on a d20 roll, this is a critical success. A critical success still needs to beat the DC (or equivalent). It is not an “automatic” success. Attacking: Your attack is a critical hit. You deal double whatever damage you roll for your weapon plus the critical effect listed on the weapon (if it has one). Skills: You add 5 to the result of the skill check. Saves: You add 5 to the result of the save check.

The roll of a natural 1 on a d20 roll always results in a failure regardless of the total result of the roll. If you spend a Hero Dice on a roll of a natural 1, it is no longer an automatic failure.