Each time a HERETIC ASTARTES DAEMON VEHICLE unit from your army makes a Dark Pact, it can invoke its contract. If it does, subtract 1 from the resulting Leadership test when making that Dark Pact, and until the end of the phase:
• Each time a model in that unit makes a ranged attack, add 1 to the Wound roll. • Add 2 to the Attacks characteristic of melee weapons equipped by models in that unit.