Chess Sudoku takes the classic sudoku game everyone knows and loves and creates 3 different puzzles with chess-related twists! In Knight Sudoku, in addition to the normal rules of sudoku, a digit must not appear a chess knight's move away from itself. King Sudoku and Queen Sudoku work the same way with a few differences. In King Sudoku a digit must not be a single diagonal move away from itself. In Queen Sudoku, every 9 in the grid acts like a chess Queen and must not be in the same row/column/3x3 box or diagonal of any other 9.