The Prison of Elders is a cooperative player-versus-enemy arena that consists of five rounds of three waves, each round and wave being random. The final round has a random mini-boss. Each round will take place in a room that corresponds to an enemy species: Fallen, Hive, Vex, and Cabal. Rounds may also have modifiers enabled. In each wave, enemies spawn and must be eliminated. Some waves have an additional objective, such as defusing mines, destroying mines, or eliminating a target, that must be completed within a time limit. If all members of the fireteam die or if the objective is not completed before time is up, the team must restart that round.