[quote=@Cultural Titan]
[@ArenaSnow]
 You may also notice that I have neglected to think of a way for the crowd to be protected from all this and you'd be right i hadn't thought of that at all. Oops. I should fix that sooner than later.
[/quote]

In the Mech warrior 4 mercenaries game there was just a dome shield around the arena. you could make up something like that, but say that it is too large or consumes too much power to be mounted on a mech.

or, its all being shot by camera drones and cameras mounted to the walls and such.