Precise

When you attack with a precise weapon, you can score a critical hit on a roll of 19 or 20. If a feature or item you have increases the numbers you can roll for a critical hit, a precise weapon increases that range by one. A fighter with Superior Critical , for instance, scores a critical hit on a roll of 17 to 20 with a precise weapon. Any roll lower than 20 must still hit to b e a critical hit - it's not an automatic hit as if the roll was a 20.