Weapons that use a template, such as a stone thrower or cannon, inflict D6 hits on any unit in a building that is touched by the template. If a building is hit by a stone thrower, these hits are resolved at the higher Strength only if the centre of the template lies over the building, otherwise the lower Strength is used instead. However, no single model can suffer more than one hit from any template weapon.
For example, a building is hit by a cannonball. The unit inside suffers D6 Strength 10 hits. As the cannon has thespecial rule, all unsaved wounds will multiply to D6.