All ordnance weapons use the large Blast marker – which is 5" in diameter. Place the marker over the target unit you want to shoot at. Next check that the target is within range and that the weapon has a line of fire to it. If the target is out of range or out of sight the shot will automatically miss. The ordnance Blast marker may not be shifted by the defender as with ordinary Blast markers; it has a chance of scattering of its own accord as noted below.
If the target is in range and can be seen the massive blast of an ordnance weapon means it's going to be very hard to miss. Nonetheless the shot may not land exactly where it was intended to. Roll the Scatter dice and a D6 to see where the shot lands. If the Scatter dice rolls a HIT symbol the shot lands on target. If an arrow is rolled the marker is shifted in the direction shown by the arrow the number of inches indicated on the D6.
Any models which end up under the Blast marker will be hit automatically. Roll a D6 for models that are partially under the marker: on a 1-3 they are unharmed, on a 4-6 they are hit by the full force of the blast. Vehicles will be hit regardless of whether they are fully or partially under the Blast marker.
Resolve ordnance hits with the Strength and Armour Piercing values on the Ordnance table.
Diagram: Firing Ordnance. A Leman Russ battle tank fires an ordnance weapon at a squad of Dark Eldar. The Blast marker is placed to show where the weapon is aiming for (shown light grey). A Scatter dice and D6 are then rolled to see where the barrage actually lands. An arrow and a 4 are the result and the template is moved 4" in the direction the arrow is pointing. The barrage blast (shown dark grey) lands on two members of the squad but as it only partially covers them the Imperial Guard player has to roll 4 or more on a D6 for the blast to have any effect (hit on 4+).