[url=http://www.roleplayerguild.com/topics/80287-arena-faq-advice/ooc]Arena FAQ[/url]

Have a look in there and have a talk to [@Rilla]. He's pretty much the go to guy with Arena stuff and seems to enjoy helping others out with the format and understanding.

[quote=@Koda]
I'm hazarding a guess of gladiatorial battle writing, yes? How is the victor decided?
What is the methodology of said section? 
[/quote]
From what I remember, cause it's been a while since I peeked into that area, you and your partner write a dual of sorts and play it out as best as possible. Your choice in movements and actions will impact what happens in future posts and how your character will react. For instance, choosing to swipe a sword across at head level may allow your partner to duck in their next post an avoid their attack; but if you choose to swipe lower they can't perform that dodge and will be hit. This may sound like a better move however if your opponent has a shield, they could block that attack and counter it.

You go back and forth with each post until someone wins. Most of the time it would make logical sense as to who is performing a decent move and who is perhaps power playing the situation, so there has to be a bit of trust between players in order to play well.

Also, duals aren't limited to sword fights. Some of the better buys in that section have had full on Dragonball Z Super Saiyan duals and such.