Bungie's bestselling military science fiction FPS, Halo, has spawned an impressive amount of content over the years since Halo: Combat Evolved was released for the Xbox in 2001. Debuting alongside Halo was the franchise's first tie-in novel, The Fall of the Reach, by Eric Nylund. Since then, there have been more than 30 novels written by a host of authors set in the wildly popular Halo universe.