Once per game, a unit with this special rule may perform a 'Drop Rocks' attack against a single enemy unit that is not engaged in combat. To do so, this unit must move (by flying) over the unit it wishes to attack during the Remaining Moves sub-phase. Once this unit's movement is complete, the enemy unit suffers D3 Strength 4 hits, each with an AP of -, for each model in this unit that moved over it.