I did come up wit a slight variation, though the puzzle I designed didn’t make the puzzle difficult enough for my tast. Anyway, I’d like to present this variation to the world.

The rules are simple:
– every row and column, and every 9 sized area, contains 3 checks.
– the checkmarks are never adjacent horizontally or vertically. They may be adjacent diagonally.
– some checkmarks have been pre-filled, as well as some empty squares.

Here are three examples.
puzzle 1^*
As you can see some checks and some empty positions have been given. You hve to derive the position of the remaining checks.

puzzle 2^*
This time only some empty positions have been given as clues.

puzzle 3^**
Again only some empty positions have been given as clues.

You can check your solutions here

A new puzzle is published every Friday.