A Better Tomorrow
When you make an attack roll and get a natural 20 (the d20 actually shows 20), you hit regardless of your target’s Defense, and you score a threat. The hit might be a critical hit (sometimes called a “crit”).
To find out whether it’s a critical hit, determine if the attack roll total would have normally hit your opponent’s Defense. If so, then it is a critical hit. If not, the attack still hits, but as a normal attack, not a critical.
A critical hit increases the attack’s damage bonus by 5.
A critical hit against a Minion allows no Saving Throw; the minion is automatically knocked out or killed.
Increased Threat Range
Characters with the Improved Critical feat can score a threat on a natural result less than 20, although they still automatically hit only on a natural 20. Any attack roll that doesn’t result in a hit is not a threat.