The deck is shuffled and each player receives six cards. The top card on the remaining deck is made visible and placed at the bottom of the deck at a 90 degree angle (so that its denomination and suit are visible). This determines the trump suit. The revealed card is actually a part of the deck, the last card to be drawn. The player with the lowest trump is the first attacker.
The attacker opens the turn by playing one card face up on the table as an attacking card. The player to the attacker's left is the defender. Ace is the highest rank and six is the lowest. Trumps always beat non-trump cards regardless of rank (e.g., a trump 6 beats a non-trump ace).
The defender attempts to beat the attacking cards by playing defending cards from their hand. One card is played in defense of each attacking card. Non-trump attacking cards may be beaten by either a) a higher card of the same suit or b) a trump. Trump -attacking cards may only be beaten by higher trumps. The defending cards are placed on top of the attacking cards so that players can keep track of which card is defending against which.
At any point during a defense, the attacker or any third party in line can pitch in extra attacking cards, provided that for each new attacking card, there is already a card of the same rank on the table (either defending or attacking), and the total number of attacking cards does not exceed the number of cards in the defender's hand. The defender must also defend against these new cards.
If the defender is unwilling or unable to beat all attacking cards, he must pick up all the cards on the table—including all the cards the attackers pitched in—and incorporate them into his hand. At this point, the defense is abandoned. The defender may choose to abandon the defense at any point during the turn. This immediately ends the turn. The failed defender loses her or his turn to attack; hence the player to the defender's left attacks next.
If, however, the defender has beaten all attacking cards, and no other players are willing or able to add more, the defender has triumphed. The turn ends, all cards on the table are discarded from play to a discard pile, and play passes to the left: the successful defender opens the next turn as the new attacker.
At the end of each turn, whether or not the defense was successful, the following action is performed: starting from the main attacker, followed by anyone else who contributed cards, and culminating with the defender, each player with fewer than six cards in their hand must draw cards from the deck until they have six cards in their hand. When the deck runs out of cards, play simply carries on without any more cards being drawn. At this point, when someone runs out of cards, they are done with the game, and everyone else continues. Each player draws as many cards as they need (e.g. if there are six cards left in the deck and the attacker has just spent their entire hand, they draw the entire deck and no one else draws any cards). The order in which this is done is strategically important since the last card in the deck is by definition a trump.
The last person with cards left in his or her hand is the loser (the fool or "durak"). That person is the dealer for the next game, and the person to the fool's right is the first attacker of the next game.
These are the basic rules to the game, although there are several variations.