Prison of Elders

Prison of Elders is a three-player cooperative arena activity that was included in the Destiny expansion House of Wolves. It focuses on variety, replay value, and skill in the House of Wolves endgame. It is unlocked after completion of the quest The Kell of Kells.

Gameplay
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.

There are no checkpoints in the Prison of Elders. Guardians who quit a Prison of Elders activity before it is completed will not be able to resume where they left off.

Upon completion of the final round, all participating Guardians will be able to access the Treasure Room and open the two loot chests and one large chest within, which contain materials and rare rewards.

Base Modes
The base Prison of Elders modes available are level 28 and level 41 matchmaking activities. Each of the first four rounds goes through a different enemy species but the round order is random each time, the modifiers are random, and the final boss round will select a random mini-boss. Self-respawns are enabled.

Challenges
There are also higher-level challenge modes available in the Prison. These modes disable self-respawns and have pre-defined rounds, waves, and modifiers, as well as a Challenge Boss. The level 32 and 34 activities change every week, but the level 35 activity always stays the same. The available challenges in these modes are as follows:
 * Broken Legion
 * Cult of the Worm
 * Machine Wrath
 * The Forever Eater
 * Urrox's Grudge
 * Skolas's Revenge (level 35 only)

Challenge of the Elders
The Level 42 Challenge of Elders requires an Elders' Sigil purchased from Variks. There are three rounds, each having one boss that must be killed. Killing enemies grants points, and different types of kills grant bonus points each week. Players will earn a weapon from Variks by obtaining 30,000 points in a single run and an armor piece by obtaining 90,000 points across all runs.

Mini-Bosses

 * Val Aru'un
 * Pilot Servitor
 * Wretched Knight
 * Overmind Minotaur

Challenge Bosses

 * Valus Trau'ug
 * Kaliks Reborn
 * Gulrot, Unclean
 * Urrox, Flame Prince
 * Qodron, Gate Lord
 * Skolas, Kell of Kells

Rewards
Upon completion of a Prison of Elders activity, all participating Guardians will be able to access the Queen's Crystal Barrows, also known as the Treasure Room, which contains two small loot chests and one large loot chest called the Queen's Chest.

Level 28

 * House of Judgment +10 per round, +15 completion bonus, total of +65 reputation
 * +6 Vanguard Marks
 * +25 Reputation

Level 41

 * House of Judgment +20 per round, +50 completion bonus, total of +150 reputation

Weekly
Weekly Challenge rewards can only be earned once per week per Challenge activity beginning at the Weekly Reset. Each activity has its own set of rewards independent of the other activities. Weekly rewards are awarded to the fireteam as soon as a Guardian opens one of the small loot chests.

Level 32

 * House of Judgment +200
 * 1 Armor Core

Level 34

 * House of Judgment +300
 * 1 Weapon Core
 * 1 Etheric Light

Level 35

 * House of Judgment +500
 * 1 Armor Core
 * 1 Weapon Core
 * 1 Etheric Light

Level 41

 * 1 Sterling Treasure

Small Loot Chests
The small loot chests can be opened each time a Guardian completes a Prison of Elders run. There is no limit to the number of times this chest can be opened per week. A loot chest has a chance to award one of the following:


 * Motes of Light
 * Strange Coins
 * Resources
 * Treasure Key

Queen's Chest
The large Queen's Chest can be opened each time a Guardian completes a Prison of Elders run (which previously required a Treasure Key). There is no limit to the number of times this chest can be opened per week. The Queen's Chest has a chance to award one of the following:


 * 1 random Queen's Wrath weapon:
 * Her Right Hand, Legendary Auto Rifle
 * Payment VI, Legendary Pulse Rifle
 * Hygiea Noblesse, Legendary Scout Rifle
 * Her Mercy, Legendary Hand Cannon
 * Her Courtesy, Legendary Shotgun
 * Her Benevolence, Legendary Sniper Rifle
 * Techeun Force, Legendary Fusion Rifle
 * Wolves' Bane, Legendary Machine Gun
 * The Dreamwaker, Legendary Rocket Launcher
 * A chance for an exotic weapon or armor
 * Weekly challenge only:
 * Class Item
 * Skolas's Revenge only:
 * Hildian Seeker jumpship
 * Kellbreaker emblem

Cores and Keys
Weapon Cores, Armor Cores, and Treasure Keys were previously used to purchase items from Variks or to open the Queen's Chest. Instead, they can now be dismantled for bonus reputation for House of Judgment.

Skolas
Immediately upon killing Skolas, the following rewards have a chance to drop once per week per character:


 * Wolfslayer's Claw II
 * Wolves' Leash II
 * Aegis of the Kell II
 * Six Dreg Pride II

Trivia

 * Parts of the Prison of Elders were repurposed in the form of the Warden of Nothing Strike in Destiny 2.