You play against Android. At the beginning of each round you will receive one card and then you have to bet something on. Android bets the same amount. After bet you continue by taking next cards from the deck until you reach the sum of 21 or at least
similar. Exceeding sum 21 means an automatic loss.

If you receive the seven-value card as a first card, you can return it before you start betting. For the Seven of Hearts card, its value can be changed between 7, 10 and 11 during the game play. If you get an eight-card and seven-card consecutively, or 5 low cards (J, Q, K), you can return them and start a new bet with a new card.

The highest figure and automatic win are two aces (the so-called "royal win") and then 21.
The winner has the highest figure or the most will approach 21.