Get black jack
Combine the cards in each slot to 21. Get more points by making 21 with just 2 cards (Black Jack) or get 21 Blitz by combining 5 cards to 21!
Discard cards
The sum of each slot is not allowed to exceed 21. If all slots are full and you cannot place the drawn card anywhere you then have to discard this card or use the joker instead.
Joker
You get one Joker per deck to play. The joker combines any slot to 21! Use it to get rid of the hard stacks or when you are stuck.