Forty Thieves is probably the most popular solitaire game played with two decks. But it takes a lot of time,luck,and skill to win. The goal in this game is to build the foundations up in suit from Ace to King. The tableaus are build downwards by suit,and only one card can be moved at a time. Empty tableau slots can be filled by any card. Click the stock pile at the top left corner to deal a new card.