Ranks.
The hierarchy within the Prison was decided by ranks– and the ranks were decided through battle. It seemed old-fashioned, but even the staff of the prison treated it as entertainment– even placing bets on the prisoners themselves.
It wouldn't be an exaggeration to say that the battles have become a daily event; no, one might even say that it was an hourly event since battles could happen in the prison at any given time. But of course, if no one was there to see it, then it might as well have never happened.
And so, usually, when someone wants to rise in ranks, a certain preparation would happen– there was issuing a challenge in front of many witnesses, setting the time, and then there was the actual battle. Sometimes, however, those three all happen at the same hour.
