Happy Halo Map Pack Day! As of today, Halo 3's formerly $10 set of maps, the Heroic Map Pack, is now free. This add-on lets you add new battle zones to the Halo 3 game. The pack consists of the Rat's Nest, Standoff, and Foundry maps, where players are provided with things like labyrinthine mazes (Rat's Nest) and editable objects that can be used to create a custom battlefield (Foundry). The next series of maps, the Legendary Map Pack, will be available on April 15th for 800 Microsoft Points.