“ECHEC ET MAT” (CHECKMATE) is a new puzzle with which you may build many shapes, both flat and three-dimensional.  Nothing was left to chance in the initial shape. Each piece of the 8x8 square has been logically designed:
- all the pieces are generated by a 4x2x1rectangle
- then a unit square is removed from it in every possible way
- then 2 unit squares are also removed from it in every possible way.

The pieces are made one unit thick and are colored using a checkered pattern. Thus we end up with ten “ reversible ” pieces, as pictured page 2 of the original problems booklet. Because of this logical process, the pieces are all different and the family of pieces is “complete.”
We can focus our attention on four types of problems:   
- “ flat ” (two-dimensional) shapes, with or without alternating colors
- “ volumetric ” (three-dimensional) shapes, with or without alternating colors.

 The shapes you are challenged to build are drawn on squared paper in order to show their size. Of course, these illustrations don’t give away the actual solutions. For example, one of the possible solutions to problem #1 is the initial shape of the puzzle. Most of the other shapes should be built outside the wooden tray using all the pieces.

The difficulty level is indicated for some more difficult problems (see range of difficulty page 19). A solution to the problems marked with an “ S ” is provided (see page 16). The other problems always have at least one solution. Thanks to the many possible combinations of pieces, you can also build your own shapes, as long as they contain sixty-four unit squares or cubes. Pages 17 & 18 are left blank for you to add your own designs.

 We wish you much pleasure with the exciting “ ECHEC ET MAT ” puzzle!