Pairs is a "New Classic Pub Game." It uses a simple triangular deck of cards: that's 1x1, 2x2, 3x3, and so on all the way to 10x10. There are many ways to play, but here are the basic rules:
Pairs is a simple press-your-luck game. Players take turns taking cards, trying not to get a pair. If you get a pair, you score points (and points are bad). You can also choose to fold, instead of taking a card, and score the lowest card in play. Folding gets you some points, but catching a pair could get you even more.
Pairs doesn't have a winner, just a loser. The first player to reach a target score loses, and the target score depends on the number of players. For example, with 4 players, the loser is the first player to 16 points.
There are a dozen different Pairs decks, most with their own game variants. You can also download the "Pairs Companion," a PDF containing more than 20 different games for the Pairs deck!
Players: 2 to 8
Time: 15 min