Klondike is a card game for one player and the best known and most popular version of the patience or solitaire family,[2] as well as one of the most challenging in widespread play.

The distinguishing feature of all variants is a triangular layout of the tableau, building in ascending sequence and packing in descending order.

The remaining cards form the stock and are placed facedown at the upper left of the layout.

The aim of the game is to build up four stacks of cards starting with Ace and ending with King, all of the same suit, on one of the four foundations, at which time the player would have won.

There are different ways of dealing the remainder of the deck from the stock to the waste, including the following: If the player can no longer make any meaningful moves, the game is considered lost.

[16][17] However the probability of winning regular Klondike is smaller, because sometimes there is no way of knowing the correct move without being able to see the downturned cards.

For the most common variant (turn three cards, unlimited passes), a number of studies have been made.

A Klondike-playing AI using Monte Carlo tree search was able to solve up to 35% of randomly generated games.

Digital versions of Klondike have helped popularize the game and offer advantages over playing with a physical deck.

However, if the card is first moved to a Tableau, and then to a Foundation, an extra 5 points are scored making a total of 15.