Excess wounds caused when attacking characters are normally discounted because all the effort of these attacks goes into fighting the character. As any excess wounds are not inflicted they are not counted towards the combat result. However, when fighting a challenge any excess wounds scored do count towards the combat result, even though they are not actually inflicted. This is called the Overkill rule.

The Overkill rule represents the situation where troops are watching their hero battling for his life against his adversary. All eyes are focussed on the mighty clash and both sides are yelling encouragement. If the troops see their Champion crushed to a bloody pulp before their eyes they will inevitably get a bit upset and might decide to turn tail and run rather than stick around for a dose of the same.

In practical terms the Overkill rule means that it is a positive advantage to crush a challenged enemy as overwhelmingly as possible. It also means that players will benefit if they meet a challenge with as powerful a character as possible. Players are advised to avoid taking on especially dangerous opponents with lowly Champions, although, of course, even the most modest character will generally do better than an ordinary trooper.