Halo: Campaign Evolved is the latest game to allow you to enter codes for rewards! These allow you to change the look of Master Chief as you progress through the first Halo campaign. All Working Halo: Campaign Evolved CodesEach of the code sequences you can enter for Halo: Campaign Evolved is 20 characters long. How to Redeem Codes for Halo: Campaign EvolvedUnfortunately, the process to redeem codes for rewards can’t be done in the game. Now you can log back into Halo: Campaign Evolved and head to the Customization option.