The single-player campaign follows the Imperium's Ultramarines Space Marine forces over the course of 15 cinematically-linked missions as they fend off an incursion by the Word Bearers Traitor Legion on the planet of Rhur III. There are 15 different missions in the game, many of which have different objectives including: * Eliminating all hostiles * Killing a specific unit or group of units * Destroying an object or a group of objects * Defending an object, such as a vehicle * Reaching a certain area on the map * Surviving for a set amount of turns