To celebrate the re-running of Spartan Ops Season 1, 343 Industries are giving players the opportunity to earn themselves Double XP for 10 future Halo 4
Infinity Multiplayer games, by playing and completing 10 Chapters of Spartan Ops during this coming weekend, May 3rd – 5th.
Please bear in mind that these Double XP matches will not
be available straight away. Once the required number of Spartan Ops chapters have been completed, players will receive a message in their Xbox LIVE inbox in the following days to inform them that they successfully qualify for the promotion. Players should receive their 10 games worth of double experience points on May 24th, 2013 at no later than 4:59 PM (PDT). Once received, double experience points will be awarded during the post-game summary of the next 10 Multiplayer games played, whether they be Spartan Ops Chapters or War Games Matches, or any combination of the two.
Full terms and conditions are available here