This booster set contains "un-" cards. Each card has a silver border and is therefore not legal in tournament play.

Unstable explores new areas of Magic game design and continues the tradition of bending the conventional rules of the game in a fun and whimsical way. Silver-bordered cards can do interesting and unique things that regular black-bordered cards don't typically get to do, all in the name of fun, and the set's creative elements reflect that spirit. Similar to previous un-sets, Unstable will be best experienced in limited formats like Sealed Deck or Booster Draft.  

Each box contains 36 packs. Each pack contains 15 cards.