The Gears of War 3 Season Pass entitles you to the first four installments of downloadable content that will roll out over the course of the next year, with the first releasing November 2011. Adding hours of campaign and multiplayer mayhem, these game add-ons
will be must-haves for any "Gears" fan, and the "Gears of War 3" Season Pass is your ticket to getting them at a discount the day they release. Available September 20, 2011 for 2400 Microsoft points on Xbox LIVE Marketplace, the season pass represents a 33
percent savings versus purchasing the add-ons individually, and also includes an exclusive Liquid Metal Weapon Set.
•Get four game add-ons for one low price -- a 33% savings.
•New campaign and multiplayer content plus additional Achievements.
•The Liquid Metal Weapon Set includes exclusive multiplayer skins for the Lancer, Retro Lancer, Hammerburst, Gnasher Shotgun, and Sawed-off Shotgun.
you can also buy it the gamestop stores, that's what I did, I believe you have to have the power up rewards card, either free or paid, then you just go to you account page and under the DLC tab there will be a code to put in on XBL for the season pass.