History of Redeemable

A '''redeemable''' is a reward item that is spent or opened to claim something rather than used directly. The Treasure Key is the main example: it is a single-use item.

Treasure Keys

Treasure Keys come from completing the House of Wolves story, from Ether chests, from smaller Prison of Elders chests, and from completing the first new Wanted bounty each week. Their use has changed over time, and the Destinypedia entry records the 2.2.0 change that stopped them being required to open the treasure room chest.