Description: Some say Demon Solitaire was invented by Canfield, a Saratoga casino owner, to separate inebriated patrons from their cash. Others say that Demon Solitaire was sent by dark forces to frustrate and torment serious solitaire players. Often called the most difficult of all solitaires, Demon, or Canfield Solitaire is a game of skill that is easy to learn, but tough to master.