And there were lunch time games of Kriegspiel (“War game,” in German.) Kriegspiel is a form of “blind chess,” in which two players sit side by side, each with a board, and a divider blocks the view of each other’s board. Each player makes moves in turn, and tries to imagine the moves the opponent makes. There is a referee who provides “clues,” by announcing when a piece is successfully captured or when a player cannot make a move because an opponent’s piece blocks the way. For a certain kind of mind, Kriegspiel was recess.