This is a calculator for Horus Heresy: First edition. This is designed to calculate the penetration rolls: Do you damage the vehicle you attack? Set the strength to the total strength of your attack, and the armor value to the hull you've selected. Most tanks will have an AV of 10-14, and most weapons will have S of 6-8 when attacking vehicles. If the combined strength and roll of the dice is under the AV, you fail. If the combined strength and dice roll is equal to the AV, it's a glance and you do the damage marked on your weapon. If it's greater, it's a penetration and you roll on the damage table (Not included.) Edit: This still operates in the same way as 2.0.
Horus Heresy: First Edition. Getting this in before the 2nd edition :p Horus Heresy is property of Games Workshop, I do not claim ownership of Horus Heresy or any affiliated affects.