The Halo Series Overview

The Halo Series Overview

The developer of Halo: Combat Evolved, Bungie Studios, originally conceived and created the title for the Apple Macintosh, but when Bungie was purchased by Microsoft in 2000 it was very quickly converted to the Xbox platform as one of its launch titles, and developed into one of the strongest titles for that platform and the year. 

The release of the games in the Halo series was not in chronological order pertaining to their actual occurrence in the story-lines, due to the out-of-sequence insertion of the prequel, Halo: Reach.  The actual release order was:

Halo: Combat Evolved
Halo 2
Halo 3
Halo Wars
Halo 3: ODST
Halo: Reach
Halo: Combat Evolved Anniversary
Halo 4

If you are just starting the series and you want to play them in the order in which the events in each game actually unfolds, you should be playing them this way:

Halo: Wars
Halo: Reach
Halo: Combat Evolved / Combat Evolved Anniversary
Halo 2 (Only the PC Version has Achievements)
Halo 3: ODST
Halo 3
Halo 4