What is the king's semi barbaric method of administering justice?

Whenever a citizen is accused of a crime, they are put into an arena. The arena is circular with two doors. Each door has skins on them to prevent any sound from escaping. Across from the two doors is a box for the king to watch from. The accused must choose on of the two doors. Behind one is a Tiger, behind the other, a lady. If the door with the lady is chosen, they are married. If they choose the door with the tiger... well you know. Also, the doors change every time, so you never know what is going to happen.