Shamrocks Solitaire Card Games
Shamrocks is one of my favorite pile based solitaire card games. The trick is that no pile is allowed to have more than 3 cards in it at a time. Aside from that, the rules for building on a pile are remarkably flexible. You can build the piles up or down, without paying attention to suit. You have to be careful not to remove the last card from a pile until absolutely necessary. Once you've removed all the cards in a pile, the pile is gone for good. You can't start a new pile in it's place. Like in a lot of other solitaire card games, you win the game once you have built up the foundations from Ace to King by suit.
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