Access via Shadowforge Lock or Detention Block
Only required for getting access to the Dark Iron Legacy quest and/or you plan to trespass the upper level of the ring unharmed.
To complete the quest Dark Iron Legacy go to the upper level after finishing the Ring of Law event and turn right.
Stand in the middle of the ring and defeat 3 waves of non-elite monsters and 1 mini-boss to get the upper level of the Ring of Law to neutral.
No special tactis. AoE the hell out of them or keep the healer alive if no AoE is available.
The Ring of Law can be bypassed by going past the Shadowforge Lock, if you have the key already, which is obtained from the quest Dark Iron Legacy.