|A Patience game|
Screenshot of Double Klondike
Double Klondike is a variant on the playing card game popularly known either as Solitaire or Snap-Up Patience, specifically a variant on the most well-known version of the game, Klondike. It is sometimes referred to simply as "Double Solitaire". Triple Solitaire, Quadruple Solitaire, etc. is also possible and is played.
As the name suggests, Double Klondike is a two-player game, and is played with two full packs of playing cards, minus the Jokers; for the purpose of Double Klondike, the cards should be of the same size, but each pack's cards should be distinguishable from the other packs in some way, such as a different font style on the cards' faces or different backing designs for each pack.
Seated facing one another, each player sets up a typical Klondike layout, with one difference: the two players share a communal foundation area in the space between the two layouts. The communal foundation will have eight potential stacks, two for each pair of suits from the two decks.
Each person plays their own layout as per Klondike rules, but with three-turn and unlimited-pass options applying to both players. Foundations are started and built up by suit as usual, except that there are two potential stacks for each suit. Players may build up on any foundation stack of the correct suit, whether or not that player started the stack or which player's cards are in the stack. Players may need to move fast when starting a new stack in order to build on it; for example, if both players have a Two of Hearts available to play, one player who is about to begin a foundation stack with the Ace of Hearts would need to act quickly to place the Ace and then place his Two before the other player places her Two first. Thus, a foundation stack might have any combination of both players' cards.
A number of informal playing conditions are usually agreed for competitive play:
The game is over when both players have no legal moves left. The cards in the foundation stacks are then sorted according by deck of origin, and the number of cards from each deck are counted. The winner of the game is the player with the highest number of cards in the foundation stacks at the end of the game.