If more than one army is involved in a battle, alliances may be made with races that may not normally ally, subject to further rules. Imperial Armies may ally with each other, or may fight each other. Imperial Guard Armies should choose whether they are renegade or loyalist, as no Space Marine or Sisters of Battle will ally with renegade Imperial Guard. Space Marines Special Characters Special Characters may only be used in battles where both sides agree to their use. Some special characters are available which are specific to this campaign.
Some armies have access to bombardment of the enemy by ships in orbit.
This is the level of Electromagnetic interference that must be cut through to call in a bombardment. At the beginning of their turn, a player with Orbital Bombardment rolls a d6. Equal or better than the interference, and they may call in a bombardment. Also, only armies containing certain models may use orbital bombardments. If these models are killed, that army may no longer use orbital bombardments.