And while Matthew wasn't able to answer all our questions--the matchmaking team had already taken off for the holiday, so they couldn't tell us if there's an option for online players to seek out other DLC owners--he was able to shed some light on other aspects, including the new areas, why there aren't new foes in Riot Mode's ever-increasing enemy waves, the reasons behind the later PlayStation 3 and PC releases, and just why Gearbox is charging for more in-game storage.

Shack: The first downloadable add-on, The Zombie Island of Dr. Ned, was accessible pretty early in the game. How and when do we get to Mad Moxxi's Underdome Riot?

Matthew Armstrong: The Lobby area is accessible almost immediately, so you can get to the new shops and start using the bank really early on. You can battle in the arena starting around level 10, but generally we recommend you wait until you have a Class Mod to tackle it (you get your first class mod around level 18). It's pretty challenging. Level 50 characters will also particularly enjoy the challenge.

Shack: Some over and under-leveled players were upset that Zombie Island's enemies and quest levels were based off one's story progress, not character level. Does Max Moxxi use the same approach?

Shack: How do the three new Riot Mode areas differ from one another?

Matthew Armstrong: The designers created three distinct combat areas which each require different tactics and gameplay.

Hellburbia is all about street fighting. It's a small neighborhood of buildings you fight around or on top of with lots of chokepoints and tactical options. The combat is very assault/defend themed as the enemies spawn at various buildings and you have to move in to take them out.

The Angelic Ruins was based upon the ending sections of our game - the pretty snowy areas with alien ruins. Many of our players told us they wanted to spend more time there. The Ruins are hilly and open. You can't see very far, but there are almost no chokepoints. You have to keep moving to stay alive there.

The Gully is a large outdoor arena in a large canyon. It winds from the bottom, which is a dense bandit camp, up and around past the Crimson Lance region to the top where there are some premium sniping locations. There's also a teleporter that takes you from the high ground to the bottom of the gully and back again, but the badguys know how to use it too!

Shack: Judging from the screenshots, it appears that Riot Mode's "onslaught of Pandora's baddest enemies" includes some returning bosses. Are there any new enemies as well?

Matthew Armstrong: Moxxi is doing some wild and unexpected things with her Maxims which change the nature of the game constantly. Unfamiliar enemies combined with the new rules tended to frustrate players during playtesting because they couldn't make the tactical decisions and they didn't feel as if their fate was in their own hands. We want the Underdome to be challenging, not frustrating, so you will be fighting familiar enemies with in decidedly unfamiliar ways.

Shack: Beyond the new Riot Mode, can you describe some of the new quests and areas in Mad Moxxi?

Matthew Armstrong: Outside the Underdome is a cool lobby area with a bank for storing your stuff and a couple of nice shops. Beyond that we fully focused all out attention on the Underdome, making it as solid and entertaining an experience as possible.

Shack: Can you elaborate on the new bank feature? Is it just weapon storage, or all items? How much extra capacity does this allow players? Will bank storage access be available throughout all of Pandora, or only in the new Mad Moxxi areas?

Shack: Why add the new bank feature in a premium-priced downloadable add-on instead of a free patch?

Matthew Armstrong: Once again, it requires space. It has to exist somewhere, and there is no easy way for us to add new space to a completed game. There are some boring technical reasons but it all boils down to restrictions on space allowed for the free title updates that we can distribute to the platforms. Your audience has surely heard developers bemoan that challenge before.

Shack: Does Mad Moxxi raise the game's level cap? If not, why, and is that something that's coming in a future download?

Matthew Armstrong: Early on, we said we would dedicate our DLC to giving the players what they want. We have many loyal fans who have played the game for a long time asking us for a place to really challenge themselves and show what they can REALLY do. Riot mode is not about growth! It's about proving yourself. It's about over the top co-operative combat and seeing if you're as tough as you think you are.

We have two tiers of tournament. The small tournament is five waves and gives a real nice prize at the end. It's a challenge, but it's designed to be something that anyone can tackle with a couple of friends. Each of the three coliseums takes about 2 hours in the small one, so there are six hours of repeatable gameplay in that one. But for the hardcore player, we have the BIG Tournament, which takes you through 20 increasingly difficult rounds, with new rules added, tougher enemies, and more enemies as the rounds progress. It's an epic challenge where you have to team up with real good players and fight as a team to emerge victorious.

Some examples of these rules are things like low gravity mode or vampire mode or headshots only mode etc. As these overlap it gets to be quite intense.

Now with that being said, we do recognize that some people just want an avenue to build their character just a little more. So what we did is figured out a way to maintain compatibility across all players and also allow people who got Mad Moxxi to gain additional skill points. It's in there.

Shack: Zombie Island hit PlayStation 3 and Xbox 360 simultaneously, but Mad Moxxi is arriving on PlayStation 3 a week later than Xbox 360. Why the delay? And is there any clue as to when Mad Moxxi will be available on PC?

Matthew Armstrong: We try to get everything out to our fans as quickly as possible. Development, testing, certification, and a multitude of other factors all contribute to defining the release of DLC or games on various consoles. When we find that the release/ship dates for different consoles do not fall on the same date, we have to ask ourselves whether it's better to delay some so they all ship at the same time or to allow them to ship when they are ready, regardless of the other versions.

Shack: Is there more Borderlands downloadable content in the works?

Matthew Armstrong: Our customers called out for more story and more humor and zombies. So we made The Zombie Island of Dr. Ned. Our customers called out for a place to test their skills and have a real co-op challenge. They asked for a bank to store their stuff. So we made Mad Moxxi's Underdome Riot.

We would love to continue the trend. If our customers continue to buy and play the DLC we make, then we know we are going in the right direction, and we can afford to take the time and money to deliver on the other things players are asking for.

Priced at $10 / 800 Microsoft Points, the downloadable Mad Moxxi's Underdome Riot add-on will be available to Borderlands Xbox 360 owners on Tuesday, December 29, followed by a PlayStation 3 release on Thursday, January 7.

It's also coming to the PC, though an exact timeframe has yet to be announced.