Fallout 3 lead producer Jeff Gardiner has fleshed out the Operation: Anchorage DLC due for arrival in January.
For 800 Microsoft Points (GBP 6.80 / EUR 9.60), there will be roughly four-to-five hours of extra gameplay, Gardiner told IGN. And once downloaded, the extra content can be played through at any level - providing the player has left Vault 101. A quest objective and map marker will show you where to go.
Operation: Anchorage is a military simulation of a battle that happened long ago in Fallout 3 lore. The program exists today to help the government run counter-offensive training should the Chinese red army ever rise to power again.
As a simulation, adventurers will lose the use of their resources and have to survive within the rules of the software. The focus will be on stealth and combat, according to Gardiner, as part of Strike Team decked out with unique armour, weapons, tools and "exotic" gadgets.
Some of these you will be able to keep. Plus there will be a Covert Ops perk on offer, as well as new Achievements.
Operation: Anchorage should also look and feel "vastly different" to the majority of environments in Fallout 3, as the battle took place before the world was reduced to nuclear rubble. Gardiner said to expect plenty of bright ice and snow.
Apparently the team had a "massive amount" of art resources at hand to build the content from scratch, and has even found time to improve NPC animation and behaviour with the environment.
As Gardiner pointed out, Bethesda wants to try new things with DLC, rather that stick rigidly to the same formula.
"It's important to our team to use DLC as a way for us to flex our creativity, to try new things and answer the 'wouldn't have been cool if we did this?' question that always comes up towards a games completion; when it's too late to try them," said Gardiner.
"Don't worry, we're trying something a little different with all of our upcoming content so there will be plenty of the morally grey, multiple path quest lines everyone loves the franchise for."
Bethesda has two other batches of downloadable content planned: The Pitt in February and Broken Steel in March.
The former adds an industrial raider town in the remains of Pittsburgh, where players will face tricky allegiance decisions.
Broken Steel, on the other hand, recruits adventurers into the Brotherhood of Steel and lets play continue after the conclusion of the main quest. This, said Gardiner, also means a rise in the level cap, although by how much is unknown.
But before any of this, Bethesda plans to release a patch addressing bugs in all three versions of Fallout 3.
"We are releasing an update for all versions of Fallout 3 prior to the release of [Operation: Anchorage]. We take pride in fixing issues that are found by our fans and posted in our forums," concluded Gardiner.
Fallout 3 downloadable content will, remember, only be heading to Xbox 360 and PC. There are currently no plans for PS3 extras.
Head over to our Fallout 3 gamepage to find out more.