Shamrocks is a great pile based solitaire card game like Cruel, La Belle Lucie, and Trefoil. Shamrocks is pretty loose rules around building the piles down. You don't have to pay attention to suit, and you can build the cards up or down. The catch (and it's a big one) is that you can never have more than 3 cards in any given pile. Like most pile based solitaire card games, once you remove all the cards in a pile, the pile is gone and it can't be started again. Like in most solitaire card games, your goal is to build up the four foundations from Ace to King by suit.