Complex sentence: Bungie released the game's first DLC, dubbed the "Noble Map Pack", on November 30,2010; this map pack contains three maps, unique in that they are not based on "Reach" campaign levels.
Split into simpler sentences: Bungie released their first DLC (dubbed the "Noble Map Pack") on November 30,2010. The Noble Map Pack contains three maps, unique in that they are not based on "Reach" campaign levels.