Tippen, also known as Dreiblatt or Zwicken, is a historical German 3-card plain-trick game and was a popular gambling game for three or more players. In Denmark essentially the same game was known as Trekort.
The game was described in 19th century anthologies and encyclopedias but appears related to Loo, which was already described in the 18th century. In some locations the game was illegal.
Three to six players play with a 32-card Piquet pack. The game is also playable by two or up to ten players. Aces are high in trick-play.
Dealer pays 3 units into the pot, deals 3 cards to each player, and turns the next card for trumps. Eldest hand (or the next active player sitting after the dealer) leads to the first trick. Players must follow suit. If they cannot do so, they may be required to trump whenever possible or just when no other player has trumped before. Whether trumping is required at all should be agreed before the game. Each won trick is worth a third of the pot. Each player who did not win a single trick must pay 3 units into the pot.
In subsequent hands, if the pot contains more than just the dealer's contribution, then players are allowed to pass by dropping their cards face-down.
Between shuffling and dealing, the player sitting before the dealer cuts the cards and reveals the lowest card. If it is an ace or seven, the deal passes to the next player without playing, but the dealer's stake remains in the pool and the next dealer also pays 3 units. Players may always pass. In a variant, the deal passes to the next player but one, and both the new dealer and the skipped player pay 3 units into the pool.
Before turning up the card that determines trumps, the dealer may announce the intent to sniff. A dealer who sniffs shows the turn-up card, then takes it and discards another card face down. A dealer who sniffed and then does not win a trick pays twice the value of the pot. A dealer who decides to pass after sniffing pays once the value of the pot.
The game may be related to 3-card Loo. Tippen is German for tapping and refers to the practice of players tapping on the table to indicate that they are not passing. Dreiblatt refers to the 3 cards, and Vierblatt to the 4 cards each player holds in the respective variants. In an 1829 Danish game anthology a variant was described under the name Trekort.