The name Pi mal Pflaumen is a play on the expression "Pi mal Daumen" — "rule of thumb" or "roughly" — which also originated in that period, but now instead of thumbs, players are concerned with fruit. On a turn, players play one fruit card from their hand at a time, then they each claim one of the played cards based on the strength of the card that they played. Each card depicts a fruit, and some of the cards also feature a scoring pattern (e.g., hand in three identical fruits or two pairs of matching fruits) or a special action, such as collecting an additional plum card, stealing a card from an opponent, taking the dog to protect yourself from theft, or collecting three π cards (which can be played singly or in combination with a number card to increase the value of your initial play).
After a number of turns based on the number of players, the round ends, then players receive a new hand of cards. After three rounds, players tally their points based on completed contracts and whoever has the high score wins.