In combat, a Necron army is led by the magnificent Necron Lord, who often carries a dangerous weapon known as the Staff of Light. His elite bodyguard are the Necron Immortals, massive robots who wield heavy weaponry. Even the normal Necrons, however, are very deadly due to their Gauss weaponry, which can flay victims alive if stuck by a blast. Last but not least, the Necrons aid their rapid attacks with devices liek skimmers and Scarabs. These are small metallic parasites which will rush forwards and clamp on to whatever they can find, and then exploding. They are particluarly deadly against tanks, since they are very difficult to stop, except by massed infantry fire.
Although uncommon in the Imperium, the Necrons still pose a great threat, and no-one knows where they will strike next.