Usually places that I used to rp around had, very bad rules for arena matches. Which is why I labled myself as atier ten right of the bat, with all the 'godmod/overpowered' accusations. But after actually reading a few threads around RPG, I realize that I'm not.. that terrible.
The biggest thing, LOGIC. Without at least a hint of logic, everything about Roleplaying is ruined. IMO anyways. Any characters that can bend the laws of physics, twist reality, etc: are completely uneccassary.