When a player stands on the mesh circle at the center of this area, it starts a plot event. The entrance to the ring is closed, and High Justice Grimstone appears in the ring. This dark iron dwarf is flagged red, but cannot be attacked; his purpose is to explain what is about to happen.
He releases three waves of non-elite monsters, and then an elite mini-boss. The type of monsters and specific mini-boss which appear vary randomly between several alternatives. Monsters: varies. Bats, scorpions, worms, and slimes are all possible. Mini-Bosses: Anub'shiah, Eviscerator, Gorosh the Dervish, Grizzle, Hedrum the Creeper, or Ok'thor the Breaker.
Once the players are victorious in the ring, the ring's entrance reopens, and a second gate also opens, leading to the ring's upper levels and the rest of the instance. The arena spectators on the upper level are normally hostile, but become neutral when the ring event is won.
The Ring of the Law event can be bypassed via the west garrison side door, which can be opened with the Shadowforge Key or by lockpicking (skill 250) or its alternatives.
Alternate Ring of the Law battle (0.5 upgrade quest chain)
The alternate boss-fight is a quest in the Dungeon 2 set upgrade questline which asks the player to kill a dwarf named Theldren and his gladiators in order to retrieve the Top Piece of Lord Valthalak's Amulet. To do this, just go in the arena, use the Banner of Provocation while High Justice Grimstone is "sentencing" you, and destroy all the mobs that come out of the gates. On the second wave, where a boss should have arrived from, Theldren and some random gladiators will appear from instead.
NOTE: Do not forget to get the Top Piece of Lord Valthalak's Amulet from Theldren.
These mobs behave like a PvP group which may include mages, healers, a hunter with a pet, rogues, a dynamite tossing goblin and always Theldren himself, who is a warrior. For more information, see Theldren's page. They are immune to taunts, so they will likely go for any healers in the player's group. Crowd control is a must in order to win this battle unless the group have a high-level player to help them.
The completion of the event spawns a box of loot. I addition, you get to keep the banner in case you want to get the loot again in the future.
Loot of note
If Theldren is killed, an Arena Spoils chest appears. One of these items will be inside it: