Story Missions are just as their namesake suggests. They are missions completed in order to progress through a Campaign. Each campaign is broken into Chapters, and each Chapter into a series of Story Missions. Generally they are linear in nature, but both Alpha Company and the Apollo Security Team have sections where players will choose different missions and alter the course of the campaign. Story Missions reward Experience and Ratings when completed quickly, and some reward bonus experience for exceptional performance. Story Missions also include the many Boss Fights, and each campaign culminates in a Final Boss.