Unzipped Backpack

As an additional cost to cast Unzipped Backpack, procure a backpack. (Beg, buy, or steal the backpack.)
Shuffle all cards on the playing surface into a pile and put them into the procured backpack. Then turn the backpack upside down and dump all cards in it onto the playing surface. Each card is now under the control of the player it lands in front of. All cards that didn't land on the playing surface are removed from the game.