"Nah. There's no referee or anything. See that guy?" Atton points at a man taller than he is, with broader shoulders, shaggy hair and a lot of tattoos. He has a red band around his arm. "He's last year's champion. You sit around the platform, and he'll call up whoever he feels like fighting - or if he's beaten, whoever beats him will do it - until nobody's left. Fight is over when he - or the guy that beats him - says it is."