Includes: Decimus Pack DLC Your deck is your army in Halo Wars 2's Blitz mode. Decimus’ cards channel the boundless rage of this classic Halo adversary directly at your enemies in this hard-hitting collection.

Go to https://www.xbox.com Login to your account Hover over your account link (the top right of the screen) a menu will appear, click on the "Redeem Code" button. On the next page, click "Redeem" Enter your code Click "Confirm" Click "Confirm" again to assign the key to your account.