The Fate of Old Andrukah
Designed to puncture and to mangle, this weapon is capable of toppling even the mightiest foes. If the weapon hits, it ignores a number of levels of Unnatural Toughness possessed by the target equal to the number in parenthesis. For instance, a Felling (1) weapon ignores the benefits of Unnatural Toughness (x2) and would reduce the benefits of Unnatural Toughness (x3) by one multiplier.
Brother Argos fires his bolter (loaded with vengeance rounds) against a Hive Tyrant. The Hive Tyrant possesses Unnatural Toughness (x3), raising its Toughness Bonus from 5 to 15. The vengeance rounds are Felling (1), meaning that the Hive Tyrant’s Toughness Bonus is only 10 (5 × 2 = 10) rather than 15 against this attack.