Microsoft has announced that Halo 3 will receive its first premium downloadable content on 11th December.
The "Heroic Map Pack" features three new maps and will cost 800 Microsoft Points (GBP 6.80 / EUR 9.30) to begin with, before being made available for free in spring 2008 ahead of another map pack's release.
The three maps in this one are called Standoff, Rat's Nest and Foundry.
The first, Standoff, is described as a symmetrical valley map with bases at either end and a field of boulders in the middle, and is said to be ideal for medium sized objective and Slayer game-types.
Rat's Nest, meanwhile, promises "vast, labyrinthine passages" and an "indoor vehicular paradise" that claims to have been influenced by the Campaign mode, and works well for big team battles.
All three maps are compatible with Forge for editing, but the final map, Foundry, gets a special nod in this sense, with Microsoft identifying its industrial warehouse confines as ideal for tweaking, with every single object manoeuvrable, allowing you to place stairways, walls, bridges and tunnels as you adjust its layout to suit your multiplayer objectives.
Microsoft also says that this week's Xbox Live Arcade game will be Undertow, the much-trailed underwater shooter from Chair, which will cost 800 Microsoft Points when it releases at 9am GMT on Wednesday, 21st November.