Invade and Conquer For the war-torn worlds of the 41st Millenium, the question is not if the invader will come - merely when. Rumbling into low orbit over far-flung planets, colossal battleships herald their arrival with ground-ripping bombardments. Planetary Onslaught provides missions and new campaigns that enable you to recreate each stage of an invasion on the tabletop, with one player assuming the role of attacker and one assuming the defender. It offers new rules for Planetstrikes, Siege Warfare, and Cities of Death. It also provides datasheets for fortifications and terrain.