Art by Richard Elson
The Arena of Judgement is the centre of the judicial system on Drak and of the Drakon Empire. The venue is an auditorium is a circular venue, with seating elevated around the outside. In the middle is where Trial By Combat takes place. Here, people suspected of a crime are forced to battle a chosen combatant (possibly a Prosecutor or Sentinel) until they have either won or lost. Outside, those not directly involved with the case are able to watch procedings on a giant screen above the door. Between the two areas is a corridor, which seems to lead elsewhere within the House of War.
When Sonic the Hedgehog was falsely accused of destroying an ancient Sentinel, he was brought to the Arena of Judgement to stand trial. Instead of fighting a Drakon, Sonic was faced with a Metallix Mark 3 brought along by Doctor Robotnik. Sonic struggled but was able to escape when Tails snuck in and defeated a Sentinel. The fox then destroyed the Metallix by closing the door on it (similar to his defeat of Nutzan Bolt).
Sonic the Comic Online revealed that a character called Cedric the Elephant may have been giving Sonic advice within the arena.