Little over a month after the release of its first downloadable content pack (The Zombie Island of Dr. Ned), Borderlands is at it again. The second serving is titled Mad Moxxi's Underdome Riot in honor of the vampy ringleader who oversees the coliseum-style combat that dominates this DLC. While it has the same price tag (800 Microsoft points or $10) and follows the same naming convention as its predecessor, the similarities end there. There is no story to explore, only round after round of brutal arena combat. And though there is some good loot, you won't earn experience or increase your weapon proficiencies by killing the hordes of enemies that are thrown at you. This DLC is tailor-made for mercenaries who have hit the level cap, completed some or all of their second playthrough, and are looking to put their combat prowess to the test. Mad Moxxi provides this and only this, so anyone not interested in combat for combat's sake is advised to avoid the Underdome, and even bloodthirsty Borderlanders may find it repetitive.
The Underdome is like a big three-ring circus, and Mad Moxxi is the ringleader. The opening sequence provides an amusing intro to this eccentric character, but aside from Mad Moxxi's ringside commentary (occasionally funny, often repetitive), there isn't much of that signature Borderlands humor here. The three rings are three different enclosed combat arenas inspired by different areas of Pandora. Hell-burbia is like a cross between New Haven and Jakob's Cove; Ancient Ruins is an archaeological site similar to those near the end of the main Borderlands campaign; and The Gully is straight out of Rust Commons. Each arena is dotted with structures and varying terrain, providing plenty of room to maneuver and a number of scenic elements to use to your advantage. Though each arena is well-designed, there are only three of them, and after a few hours of combat you will likely yearn for more environmental diversity.
At the outset of Underdome Riot, you pick up a quest that challenges you to survive five rounds in each arena. One round of combat is made up of five themed waves. The first is the starter wave, generally populated by bandits and skags (the only Pandoran creature featured in this DLC). The second is the self-explanatory gun wave. The third is the horde wave, which is populated entirely by psychos. Next up is the badass wave, which features a higher percentage of badass level characters than usual. And the finale is the boss stage, which pits you against such title-card characters as Sledge, Nine Toes, and Baron Flynt, as well as lesser bosses like King Wee Wee, Reaver, and Master McCloud. It behooves you to plan for the different challenges of each round (especially the maniacal horde wave), but though enemy spawns can vary quite a bit within a given wave, the action does get repetitive. You need a hearty appetite for combat to keep the repetition at bay, though there are some factors that help keep things lively.
As you fight through waves and rounds, your enemies get tougher and more numerous. They start off a bit weaker than usual, but each round brings incremental boosts to their health, shields, and damage, up to the point where they are significantly tougher and more deadly. Additionally, later rounds impose new conditions on each wave. Some merely change the circumstances, by decreasing the gravity or improving the damage done by a certain type of weapon, for example. Others increase your enemies' strength even further (for instance, enemies spawn with better guns), while still others directly hamstring you (for example, you have constantly draining health that you can replenish only by killing enemies). When these conditions stack up and combine with the aforementioned enemy attribute bonuses, you get some of the most challenging combat on all of Pandora. Meeting this challenge solo is brutally hard, so you'd better have at least one skilled teammate along for the ride. Having someone to revive you when you can't get a second wind is key, because failure will set you back many rounds or wipe the slate clean, depending on how far you've gotten. If you die while at least one teammate still lives, you are banished to the top of a tower in the middle of the arena. You can shoot, throw grenades, and use your action skill from there, but you can't escape until your team finishes the wave.
So if you're looking for a tough challenge, then you should consider paying Mad Moxxi a visit. Just don't expect to be handsomely rewarded for it. You gain no experience or weapon proficiency for killing enemies inside the arenas. And unless you have a skill that affects enemy loot drops (like Mordecai's Swipe skill), you won't be getting anything from your vanquished foes (though you can make progress toward and complete Challenges). Frantic end-of-wave resupply drops are your only chance to get ammo or health from external sources, so it's best that you rely on your own inventory or skills. At the end of each round, Mad Moxxi does offer some richer rewards in the form of guns, shields, and class mods, and the longer you survive, the better these rewards will be. Unfortunately, there's an odd bug that occasionally causes some players to be unable to see every item in the loot drop. Communication can help you work around these instances, but it's still a bit troubling. Yet no matter how many sweet weapons or solid shields you may earn, the most precious rewards you'll find are two additional skill points, which is especially tantalizing for those who have reached the level cap.
And that pretty well sums up the target demographic of Mad Moxxi's Underdome Riot: those who have reached the level cap. If you and your buddies are looking to get the band of mercenaries back together, Mad Moxxi's relentless combat will fit the bill, and the skill points are a nice reward for your troubles. But the Underdome strips away a lot of the elements that make Borderlands so much fun, so this DLC may not scratch your itchy trigger finger. You don't gain experience or proficiency, the scenery doesn't change, the structure doesn't offer much variety, and there's precious little character or humor. Underdome Riot is a very narrow add-on with very limited appeal, but if you're dying for a heaping helping of pure combat, Mad Moxxi has got your fix.