Fight the most brutal battles of the Horus Heresy at epic scale with The Great Slaughter, the first campaign expansion book for Legions Imperialis. Along with a thick narrative section detailing the movements of Loyalist and Heretic forces around the Beta-Garmon campaign, the book includes new Detachment datasheets for both Legiones Astartes and Solar Auxilia armies, rules for fighting battles between entire armies of Titans and Imperial Knights, and a full campaign system for linking games together on the road to the infamous Battle for Nyrcon City.