The goal is to form pairs that add up to 13. Click both cards in a pair to remove them. You can only play cards that aren't blocked by other cards. 9s pair with 4s, 3s with 10s, etc. Clear all the cards from the pyramid to win.
Aces are worth 1. Jacks are worth 11 (pair with 2s). Queens are 12 (pair with aces). Kings are 13 and can be removed by themselves.
Stock and waste
Tap the cycle button to move cards from stock to waste. You can cycle through the stock only 3 times so play wisely.
Any uncovered card can be part of a pair. You can match the stock with waste cards. The game ends when the pyramid is cleared but, before then, match cards in stock and waste for extra points. Just don't use cards you'll need to clear the pyramid.