Halo Reach, Halo Wars, Halo 3 & 4 DLC FREE via the Xbox Store

In preparation of Halo 3, Halo 3: ODST, Halo 4, and Halo: CE Anniversary joining Xbox One backward compatibility later this year, several Halo DLC are now permanently free. Check below for the full list.

Halo 3

• Cold Storage Map
• Heroic Map Pack
• Legendary Map Pack
• Mythic Map Pack
• Mythic II Map Pack

Halo 4

• Champions Bundle
• Forge Island
• Spartan Ops Season 1: Episodes 6-10
• War Games Map Pass

Halo Reach

• Anniversary Map Pack
• Defiant Map Pack
• Noble Map Pack – Newly Added

Halo Wars

• Historical Battle Map Pack Add-on
• Strategic Options Add-on Pack

You can check out more info about the Halo Summer Celebration here.