Anti-Knight Sudoku

Rules

Placed as a chess knight would move — two cells one way and one the other — two squares may never contain the same digit. It is invisible at first and then it is everywhere.

• No two cells a knight’s move apart may hold the same digit.
• The knight move ignores boxes and rows; it cuts across them.
• Every digit you place knocks out up to eight distant cells.
• Board edges shrink the effect — corners have fewer knight neighbours.

Good to know

Ordinary sudoku rules still apply underneath the variant: every row, column and 3×3 box holds 1–9 exactly once. The extra rule sits on top and is usually what breaks the puzzle open.

More sudoku

All sudoku variants ↗

Or read how to play Sudoku ↗.