A Campaign centered around an Arena?

I love hack n' slash as much as I love roleplaying. So I figured, why not have a campaign where the PCs are all combatants in an arena? They could be there voluntarily, or criminals who showed great promise and are now being placed on a "team" with the other PCs. There is no death once you get put on a team. It's like you're a "made man". That's where the PCs are at. But of course, their popularity and profitability could wax and wane. If they become too much of a problem they're booted out (executed). The party will have free reign of the Arena grounds, and even be able to interact with the outside world via a "visitation" room of sorts, which I figure might allow for all kinds of intrigue. And, perhaps - the party could be "loaned" out for quests outside the Arena proper and we could mix in some more traditional sessions in there too. I figure there might be enough behind the scenes drama to make it interesting enough to provide ample opportunity for roleplaying as well. But I was just wondering if you guys had any input on this idea and stuff you would do or add to the Arena to increase the RP potential. Thanks!

There are a few game systems built around this idea.   White Wolf had a Street Fighter game that used combat cards and a hex map it is all about playing a fighter in the street fighter universe and had tournament rules in one of the books.   There are a few wrestling based RPG's out there I love an out of print one for the WWF it was great fun role playing to the crowd and having mic time trash talking your opponent, also used this for a tournament at a local game store. There are tactical games like Battle Tech that are good fun and they have role playing rules added to them in seperate books so you could run a robot fighting league style game. Mordheim made a pit fighter game for it's miniature battle world called "Pit Fighter" it is still floating around the internet. There is 3rd party support for PvP Pathfinder games from a company called Conflict Games, you can find there stuff on the Piazo website. Ancient Greek style PvP is what the role playing game Agon is all about playing gladiators in an arena. I am sure there are more but those are the ones that come to mind at the moment.

GURPs "Man to Man" was built to be a PvP. Don't know if it can be found since it is so old (back in the 80s) but that is another one.

Good news! "Hack n' slash" and arena combat are roleplaying. So by playing a game like that, you'll have plenty of roleplaying just by playing. If by "roleplaying," you mean "non-combat interactions," there is as much opportunity for this as in any other premise-based game because it is a matter of player choice. D&D 4e provides excellent mechanical support for such a game and WotC published some articles on gladiatorial-style campaigns in Dungeon and Dragon which may be of some use to you. Dark Sun is a good setting for this sort of thing.

I played in a D&D 3.5 arena game and we had a blast! The arena would change from week to week. Different themes or obstacles we had to deal with. It was fun. DM got burnout, but he was new to it all. cool idea.