The Madhouse Collection is a promotional set of cards released on December 14, 2016 to coincide with the first Chaos Arena. It consists of ten cards and a single Arena Ticket. You will receive three copies of these cards. The Collection can be purchased with money (USD $9.99/€9.99/£7.99/AUD $14.99) or with 1,500[verification needed] in-game Gold.
The Madhouse Collection consists of the following cards:
|Altar of Despair||Support||Neutral||6||–||–||Legendary||Uses: 12
Activate: Sacrifice a creature to summon a creature from your deck that costs 1, then increase the cost of creatures this summons by 1.
|Close Call||Action||Neutral||0||–||–||Rare||Unsummon a friendly creature.|
|Forsaken Champion||Creature (Reachman)||Neutral||5||3||3||Epic||Summon: Choose a friendly creature.
Friendly creatures of the chosen type have +1/+1.
|Gardener of Swords||Creature (Redguard)||Intelligence||3||1||1||Rare||When you equip an item to another creature, equip a copy of it to Gardener of Swords.|
|Illusory Mimic||Creature (Spirit)||Neutral||6||5||5||Epic||Summon: Illusory Mimic gains all Keywords on the top three cards of your deck.|
|Merchant's Camel||Creature (Beast)||Neutral||4||1||4||Common||Summon: Look at the top three cards of your deck. Put one into your hand and discard the others.|
|Ring of Imaginary Might||Item||Endurance||4||Rare||+0/+2
Summon: The wielder's power becomes equal to its health
|Shivering Apothecary||Creature (Imperial)||Willpower||4||2||2||Rare||Summon: Summon a random elixir.|
|Stoneshard Orc||Creature (Orc)||Strength||3||2||1||Rare||Summon: Deal 1 damage to an enemy creature for each friendly Orc.|
When you play a 0-cost card, deal 1 damage to your opponent and gain 1 health.