(This article was based on this Wikipedia article).
Taking a standard 52-card deck of playing cards (without Jokers) one upturned card is dealt on the left of the playing area, then six downturned cards (from left to right). On top of the downturned cards, an upturned card is dealt on the left-most downturned pile, and downturned cards on the rest until all piles have an upturned card. The piles should look like the figure to the right.
The four foundations (light rectangles in the upper right of the figure) are built up by suit from Ace to King, and the tableau piles can be built down by alternate colours, and partial or complete piles can be moved if they are built down by alternate colors also. Any empty piles can be filled with a King or a pile of cards with a King at the top.
There are different ways of dealing the remainder of the deck:
- Turning three cards at once to the waste, either allowing three passes through the deck or placing no limit on passes through the deck.
- Turning three cards at once, reversing the order of each group of three as the cards are dealt.
- Turning only one card at a time, but only passing through the deck once.
- Turning only one card at a time, but placing no limit on passes through the deck.
- Michael A. Casteel's shareware version of Klondike for the Macintosh was first released in 1984, and has been continually updated since.
- A software version of Klondike, simply named Solitaire, has been included in all versions of Microsoft Windows since Windows 3.0 (1990). However, Windows computers used in business or educational environments may have had the game removed to prevent distraction. The embedded versions of Microsoft Windows, originally called Windows CE and now called Windows Mobile, have also included Solitaire.
- GNOME and KDE have solitaire applications (sol and kpat) since early versions.
- Soltrio Solitaire will include Klondike for Xbox Live Arcade, for which the gamer will earn Achievements.
- Klondike is one of the games included in the modern iPod's "Extras" section.
- Klondike is available at online casinos using Cryptologic, Grand Virtual, Cantor Gaming, and 3Dice software.
Odds of winning
For a "standard" game of Klondike (of the form: Draw 3, Re-Deal Infinite, Win 52) the number of solvable games (assuming all cards are known) is between 82-91.5%. The number of unplayable games is 0.025% and the number of games that cannot be won is between 8.5-18%.
"Unplayable" means that no cards can be moved anywhere. This should not be confused with a game that has been "lost" after some moves have been made (but failing to move all cards to the foundations). A game that has been "won", in this case, has 52 cards placed to the foundations. So, there are unplayable lost games, playable lost games, and won games.
A modified version of the game called "Thoughtful Solitaire", in which the identity of all 52 cards is known, has a known solution strategy that works 82% of the time but requires significant computing power. Because the only difference between the two games (Klondike and Thoughtful) is the knowledge of card location, all Thoughtful games with solutions will also have solutions in Klondike (in theory). Similarly, all dead-ends in Thoughtful will be dead ends in Klondike.
However, the odds of winning a standard game of non-Thoughtful Klondike are currently unknown. It has been said that the inability for theoreticians to calculate these odds is "one of the embarrassments of applied mathematics" 
Standard Scoring in the Windows Solitaire game is determined as follows:
|Waste to Tableau||5|
|Waste to Foundation||10|
|Tableau to Foundation||10|
|Turn over Tableau card||5|
|Foundation to Tableau||-15|
Moving cards directly from the Waste stack to a Foundation awards 10 points. However, if the card is first moved to a Tableau, and then to a Foundation, then an extra 5 points are received for a total of 15. Thus in order to receive a maximum score, no cards should be moved directly from the Waste to Foundation.
Time can also play a factor in Windows Solitaire, if the Timed game option is selected. For every 10 seconds without moving a card 2 points are taken away. Bonus points are calculated with the formula of 700,000 / (seconds to finish) if the game takes more than 30 seconds. If the game takes less than 30 seconds, no bonus points are awarded.
Below are some variations of the game of Klondike:
- In Agnes, the stock is dealt in batches of seven on reserve piles and every one is available. Furthermore, the bases of the foundations depends on the twenty-ninth card, which is dealt on the foundations.
- In Thumb and Pouch, a card in the tableau can be built upon another that is any suit other than its own (e.g. spades cannot be placed over spades) and spaces can be filled by any card or sequence.
- In Whitehead, all cards are dealt face up, building is by color (red on red, black on black), a sequence made up of cards that are of the same suit can be moved as a unit, and a space can be filled by any card or sequence.
- In Westcliff, thirty cards are dealt into ten piles of three cards, two faced down and one faced up. A space in this game can be filled with any card or sequence.
- In Easthaven (a.k.a. Aces Up), twenty-one cards are dealt into seven piles of three, two faced down and one faced up. A space in this game can only be filled by a king or any sequence starting with a king, and when a play goes to a standstill, seven new cards are dealt to the tableau, one top of each pile. Easthaven may include 2 or 3 card decks.
- In Nine Across nine columns of cards are dealt, as opposed to the seven of conventional Klondike. The player can choose which cards to form the foundations; if one or more eights are exposed, for example, the player may decide to build on eights, and the piles are built up 8-9-10-J-Q-K-Ace-2-3-4-5-6-7. If eights are built on, sevens fill up spaces and so forth. The stock is dealt through one by one as many times as required.
- The Probability of Unplayable Solitaire (Klondike) Games The unpublished Monte Carlo result
- Solitaire - Man versus Machine Analyzing a version of Klondike
- Searching Solitaire in Real Time