The Horus Heresy is a tabletop wargame set in the Warhammer 40,000 universe, specifically during the historical event known as the Horus Heresy. In this game, players command armies of Space Marines and other forces, battling for control of objectives and ultimately shaping the fate of the galaxy. The game focuses on recreating the epic conflict between the loyalist Imperium and the traitor forces led by Horus, the Emperor's favored son, as they clash in a galaxy-spanning civil war.