Klondike is a card game for one player and the best known and most popular version of the solitaire family, as well as one of the most challenging in widespread play. It has spawned numerous variants including Batsford, Easthaven, King Albert, Thumb and Pouch, Somerset or Usk and Whitehead, as well as the American variants of the games, Agnes and Westcliff. The distinguishing feature of all variants is a triangular layout of the tableau, building in ascending sequence and packing in descending order.