Case Keys are used to open multiple Cases at the same time.

The Cost to start unlocking a Case will depend on how many are currently being opened:
Unlock 1: Free
Unlock 2: 1 Case Key
Unlock 3: 2 Case Keys
Unlock 4: 3 Case KEys

Case Keys can be earned from Roulette of Prizes, Watching Ads, or by purchasing them from the Store.