Especially large weapons are called ordnance. These weapons are so huge and powerful that they cannot be physically carried but must be mounted onto a vehicle or built into the structure of a fortress. For the most part they are used by the heavily mechanised armies of the Imperial Guard. As noted in the weapons section, ordnance weapons will normally use the large Blast marker.
Ordnance weapons may also be barrage weapons, this is indicated by a 'G' (for guess) in their range, indicating that the crew guess how far the target is away and aim to drop their shots down on top of them from high. Ordnance barrages work slightly differently from normal ordnance attacks, so the two types of attack are described separately.
If an attempt is made to fire an ordnance weapon, then the vehicle may fire no other weapons, whether they are main weapons, defensive weapons or weapons bought as vehicle upgrades.
Firing on the Move. Ordnance weapons may be fired on the move, but the chances of an accurate shot are greatly reduced. Normally, an ordnance shot will land somewhere near the target but when firing on the move, the shot could go anywhere. Roll to hit using the vehicle's Ballistic Skill. If the shot hits the target, then continue to the section detailing the firing procedure for ordnance weapons. If the shot misses, then it has disappeared over the horizon, or the crew have simply been unable to aim because of the vehicle bouncing about and have not managed to fire a shot.
Designer's Note: This is another of the major changes and is also intended to make armoured warfare in Warhammer 40,000 far more dynamic. Firing on the move sacrifices accuracy but at least gives options in missions which require an army to advance. The sight of Imperial Guard infantry advancing behind the cover of their mighty tanks should once again become a common sight.