Where Containment focused on planetstrike missions, this introduces the new Treachery and Honour system, which offers new ways to play multiplayer games of Warhammer 40,000. It features 21 new missions (six each for Combat Patrol-, Incursion-, and Strike Force-sized games, and three for Onslaught games), along with a host of bespoke Stratagems, Battle Traits, and Agendas. It also includes the new Underdog system, which can help you grasp victory from the jaws of certain defeat.