The three maps in the Halo 3 Heroic Map Pack are available through the Xbox Live marketplace and will cost users 800 "Microsoft points", which can be purchased for about $10.00.

One map, called "Standoff", features a symmetrical valley with entrenched bases and boulders for cover. Another, titled "Rat's Nest", provides player with "labyrinthine passages" to work through, according to Microsoft. Finally, "Foundry" includes numerous, editable objects -- such as walls, bridges, and tunnels -- that players can place wherever they like to create a custom battlefield.

Microsoft said it plans to make the three maps available as a free download in spring 2008, just prior to the release of a new set of maps.

A first person shooter, Halo 3 features a biologically enhanced super-soldier named Master Chief who -- armed with plasma rays and other futuristic weapons -- has to blast his way through various levels to accomplish missions. He's countered by an alliance of hostile aliens called The Covenant.

Since it launched in September, Halo 3 has set numerous video game industry sales records. It posted $170 million in first day receipts, and took in $300 million in its first week. To date, more than 5 million copies of Halo 3 have been sold.

Master Chief was ensconced in popular culture when Madame Tussauds' wax museum in Las Vegas in September unveiled a 'life size' statue of the character standing 7-feet, 2-inches tall.