The aim of Klondike is to get 4 piles of cards - one in each suit - built from Ace to King.
The game starts with 7 piles of cards, forming the tableau. There is one card in the first pile, 2 in the second and so on, with 7 cards in the last pile. By default, only the top card of each pile is face up. The remaining cards are placed face down above the field to form the stock. Cards are dealt from the stock onto an adjacent waste pile. The 4 spaces above the tableau are the foundation piles where you are aiming to place all of the cards.
Cards may only be moved to the foundation piles if they are face-up. Cards on the tableau can be turned face-up when they are uncovered. Tapping on the stock will turn over cards, 1, 2 or 3 at a time depending on your settings, onto the waste pile. The top card of the waste pile and the exposed cards in the tableau piles are available to play. It is also possible to change a setting to allow the top card of each foundation pile to be playable.
The tableau piles are usually built downwards in value with alternating color, e.g. the 10 of Clubs can be placed on either the Jack of Hearts or the Jack of Diamonds. You can move any sequence of cards in the tableau on top of another pile in the tableau as long as it follows the rule. So if you had a red 9 on top of a black 10, you can move both cards at once to any red Jack. By default, if you empty a tableau pile, you may fill the space only with a King or sequence headed by a King. The foundations are built upwards in value with matching suits, e.g. the 10 of Clubs can only be placed on the 9 of Clubs.
Once you have exhausted all the available moves on the tableau, you will need to bring cards from the waste onto the tableau. Once you have been through the stock you can turn it over and start again. You can deal the cards from the stock to the waste pile one, three or an unlimited number of times depending on your settings.
Klondike is won when you have moved all the cards from the stock and tableau to the foundations. If you run out of moves before winning, the game is over.