Trefoil Solitaire is a modified version of La Belle Lucie that is slightly more difficult. In Trefoil, the player pulls the four Aces out of the deck and uses the to start out the foundations. This leaves only 16 piles instead of the 18 piles that you begin the game with in La Belle Lucie. Like in La Belle Lucie, once the piles are gone they can not be reconstituted. The player is also allowed to reshuffle the cards that have not yet been placed into the foundations up to three times.