I'd like to ask a question, which I wrote about in an Arena IntCheck just recently:

[quote]So I'll be honest: I've always scoffed a little at the idea of an arena section. Not that I think it's silly or anything, but as a RPer, my focus tends towards narrative and story-driven scenarios and outcomes. I understand the gist of writing combat, but doing so in a competitive setting never appealed to me. Who's to say just what's permissible and what's not? What if it devolves into a 'who can bullshit the best?' battle? How do you determine Player X really hit Player Y, if they both have different mental pictures of the scenario?[/quote]
So yeah - I'm curious as to how you enforce what flies in terms of hits and so forth. 
Ex. Player A does some 'jumping downward slash' while Player B's back is slightly turned - who's to say Player B can't 'sense the attack coming and roll into a counter jab' ? How do you stop battles from becoming metagame BS fests? If players interpret the angles or arcs of hits differently in their mental pictures, how do you know what gets through?

And then you potentially have it [i]worse[/i] when you factor magic and technobabble into the equation. "Oh no, that magic breath attack has no effect on my shield made of laminated windonium." Or, "I don't care what your backstory is, my char's will is stronger than ten thousand gigawatts, and no blade can pierce it!"  

This is my cause for concern in the arena section in a nutshell. And, having not participated in it before, I've no clue how these things are handled.