En Critical Hit

From the Web Addendum Vol. I:

Critical Hits
If a Character gets a result of 10 on its Attack roll, it receives a Critical Hit. Critical Hits are masterful attacks, that cut through the rival’s defenses and hit it’s weak spots. So, whenever a player achieves a critical hit, the attack is automatically successful, however high the enemy’s defense. Even in those cases when, thanks to Dodge, the enemy unit’s Defense is higher to the attacker’s Attack, Level of Success is considered to be 0. A critical hit always causes damage. Even if the Defender’s Armor would nullify it completely, the Character that has received the Critical Hit will lose at least one life point. Some attacks give a Character Special Abilities when a Critical Hit is obtained. If this is the case, its Effects appear in the ability or power’s
description.