This skill grants the character an additional 3 points of damage on all attacks against Evil (or Neutral with Hand of Zealotry) targets. The stronghold wards of Evil factions count as an Evil target for purposes of this skill. Members of Evil factions in their own stronghold who are not themselves Evil will not trigger the bonus damage of this skill.
Note that this bonus damage will not appear in the combat dropdown menu of the game interface. This is because the bonus is determined on a per-target basis. However, the bonus damage will be applied if the target is Evil and a hit is successfully scored.