Borderlands

The enemies in the arenas scale to the host's level.

Easiet way -

Get a level 10 character to host the game, and 3 other level 50 characters as co-op partners (one level 50 is enough, but you will go through it faster with more people) You will be able to breeze through the levels without any trouble.

its 5 rounds, each with 5 waves. so it will take while. so make sure you have around an hour in your hand, because you cant quit in the middle of an arena.

If you Join some one else's game half way through, you can still get the achievement, as long as you are there at round 5, wave 5. (so if you lag out, just join back in, it wont effect the achievement)

You get 1 skill point for finishing all 3 small arenas in play thorough 1, and another for finishing them in play through 2.


(you have to be atleast a 10/have fast travel to access the mad moxi dlc)

If you want to solo this achievement I recommend you equip yourself with some ammo and health regeneration mods. I played through this with a level 37 Hunter carrying the Sniper, Gunslinger and Survivor mods. Every class has at least one mod that will regenerate some type of ammo and health.
You can switch between mods quickly as needed depending on circumstances. Since you're playing solo, bringing up your inventory will pause the action so switching mods does not have to be a frantic task.

The health regen is important for the Vampire waves where you lose health over time. My Survivor health regen balanced the Vampire health drain so I didn't have to rush around looking for kills.

By bringing the right mods to Underdome you aren't so dependent on the ammo and health drops between waves. I didn't need to pick up a single drop.

If you don't have the mods you want, you can easily farm for them by starting the game at the Underdome, and do a quick check at the Medical vending machine, You can exit, check and re-enter very quickly. I got the mods I needed in about 20 minutes but remember it's random.

Another consideration is adjusting your skill tree for this type of play. Being spec'd for looting is no help in the Underdome so spend a little money to optimize for health, ammo and damage.

Hope this helps. :)

The way I did these achievements was very simple. Have your main character to be a high level character from level 50 - 69 if you have the dlcs. Using a seperate profile/gamertag train up a character through the story till they can teleport to 'The Underdome' this'll be around level 10 maybe lower. Then go into a split screen game with your low level account as player 1, use your main higher level account as player 2, the lowest the enemies can be is level 12. Play through the small tournaments, then move on to the big ones, this will still take a fair amount of time, but with your high level character things should be a breeze. Good Luck