Good news Halo 3 sports fans, Grifball getting off the bench and taking on the Halo 3 Double EXP Weekend. Prepare for high flying hijinks complete with hammers, energy swords, and one highly explosive ball. Honestly, there isn't much more to say about things. We assume you're familiar with Double EXP Weekends. They ... um ... give out twices as many experience points in Halo 3. Oh, and you'll need the Heroic Map Pack. Then again, that's free, so if you don't have it, you probably weren't going to play anyway.