Critical Rune Cannon

This ability allows a gunner to make a 1d20 roll firing a rune cannon. If the gunner rolls 15 or greater, it is counted as a critical hit, allowing you to add the maximum of your runic power to the attack. For example, if your runic power is 2d8, you will add 16 to your rune cannon blast. If you roll a 20 on the 1d20, you will also do maximum rune cannon damage along with maximum runic power. All other rules concerning criticals and critical hits also apply.