Chess sudoku variant

Has anyone heard of the chess variant of sudoku?

I have heard it mentioned somewhere that there is variant whereby chess pieces get added to the puzzle and have to attack each number exactly once - if you see what I mean.

Can't remember where I read it, but I wonder if this actually exists somewhere or if it was just an idea?

Would be interested to find out!

Steve

Chess sudoku

I LOVE sudoku and have played lots of different versions... don't think that I have heard of chess sudoku however?