Contributed by Jer Gallagher (for Brent).
Summary: points are earned and the game is won by playing cards that add up to a prime number.
Players: 2-4 (though, intended as a two player game)
Equipment: deck of playing cards (52, no jokers)
Prime numbers* that can be played:
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, and 113**
*"Lebesgue Rules" are when you count 1 as a prime as well - since he was the last mathematician to consider 1 a prime number.
**The next prime (127) is unattainable, so if anyone gets 113, they win the hand.
The deck is shuffled a prime number of times (usually 7). After the cards are cut, each player is dealt 11 cards which they hold in their hand. The top card of the remaining deck is turned over and is the "starting number".
The non-dealer (or person to the left of the dealer) adds a card from their hand that adds to the starting card to equal a prime number. The next player then tries to add to that total to equal a larger prime. When a player can no longer add a card that sums up to a prime the hand is over, and the last person to make a prime gets that many points.
The game is played in a prime number of hands (usually 11), after which the player with the highest score wins.