Any luck of information? I

Unfortunately, I have to close at work this and next thursday.

From what I remember talking to guys at Orgins '12:

Drawing magic from Voltaire (magical realm) on a wide spread basis was having adverse effects upon the world, (warping, monsters, etc) and at some point the countries/Mages realized that they could end up destroying the world they were fighting for. Eventually they agreed to only have magical duels/fights in specific locations. I believe there are multiple arenas, but they are all just called arenas.

I think they have been constructed to be resistant to effects of heavy magic use in them, though actually having different looking arena boards would be pretty cool.