I'll put it bluntly, what is arena?

P.S. someone should make a sticky answering this

Participants make a character, equipped within the point limit made by the Game Master (GM). The GM pits one character against another. From there, it's like a gladiator tournament. They prgress until they reach the finals, and then there is one winner. Your character against another person's character. It's a great way to test out magic item combinations.

Take a look at a couple of arenas here to see some exmaples.