A model with this rule can choose to make a single Tree Whack in place of making his normal close combat attacks. If a model is making a Tree Whack, it must be declared before rolling To Hit.
To resolve a Tree Whack, nominate an enemy model in base contact. That model must pass an I test or suffer D6 Wounds with no armour saves allowed. A character with this rule may make a Tree Whack in a challenge.