Disclaimer: This is a poor translation of the French game La vache qui tache ("The Cow Who Stains") by someone who doesn't know very much French. Although there appears to have been a commercial game made of it recently, the game itself has been around for a long long time.

La vache qui tache is a party game for any number of players. The only prop required is a cork, one end of which has been blackened in a candle flame.

Assign each player a number. Player one calls out "Je suis la vache qui tache avec A taches numéro X et j'appelle la vache avec B taches numéro Y" ("I am the spotting cow with A spots number X, and I call the cow with B spots number Y"). When you first start the game no-one has any spots, so A and B are zero, or "sans tache". Y can be any player, and Y must immediately repeat the phrase, substituting himself for X and another player for Y. If a player makes a mistake, like using himself for both X and Y, taking too long to respond, or calling the wrong number of spots (explained in just a moment), that player gets "spotted", using the blackened cork to make a big round black dot on his face. Each mistake earns a player another spot (and, of course, both your number of spots and the number of spots of the player you're calling must be taken into account every time you call another player). Exactly when the game ends is a little ambiguous, but usually involves a lot of giggling and someone running away from the table to avoid getting spotted.

Although the game is popular with children, it was originally a drinking game, and a French idiom for being falling-down-drunk is "black faced" in reference to this game.