Automatically confirms a critical threat in exchange for reduced damage.
When you deal a Critical Threat, you can automatically confirm the threat, but you reduce the damage dice by 2 steps.
Using a weapon with the Exact Feature has a special interaction with weapons who’s dice step would be lowered below a d4 (if damage dice could be). If your weapon damage dice could be reduced below a d4 when you use this feature, you treat results of 4 on the dice as if they were a 3 instead.