A steel cage is a prison that can be constructed in the oubliette of a player-owned house. It requires level 75 Construction to build, along with 20 steel bars. Upon building a steel cage, a player will be granted 400 experience. When the trapdoor of the throne room is activated to drop a player into the oubliette, the cage imprisons the player. To escape, the player must either pick the lock or force it to open.