Gämsh Alpin (2016)

Description from the publisher:

Gämsh Alpin is a fast card game for teams of two whose communication is on point. Thus, the game works only with 4 OR 6 players, not 5.

Before the game starts, each team of two players secretly agrees on a signal — a wink, a gesture, a word, whatever — they will use in the game. This signal should be clear enough for the partner, but not something that can be identified by other players.

Now the actual game starts, with partners sitting opposite one another. All players simultaneously exchange cards in hand with cards on the table. As soon as any player has managed to collect four of a kind, that player tries to let their partner know by giving that team's secret signal. If the team partner identifies the wink, the nudge, the code word, whatever, that team can score points. However, a vigilant opponent might just be faster and counter in time by announcing that this particular team has sent the signal. The opponent does not have to tell the group the signal. Special cards spice up the whole procedure.

Gämsh Alpin is a further development of a public domain game.