Abstract: A puzzle comprises a holder (1) defining a field of movement for rectangular pieces (5,6,7) which are slidable within said holder, the problem being to effect a sequence of displacements which will bring a key-piece (7) to a position at the opposite end of the holder (1). The key-piece can then be further moved to cause a portion (9) thereof to project out of the holder, through an aperture (8). The key-piece is in the form of a container for confectionery pieces or other objects which can be removed only by solving the puzzle and moving the key-piece (7) into said projecting position.