Anti-Knight Sudoku: Rules & How to Solve
No digit repeats a chess knight's move away. A spatial constraint that reshapes how the whole grid connects.
The rule
Identical digits may not be a chess knight's move apart (two cells in one direction and one cell perpendicular). All normal sudoku rules also apply.
How to solve anti knight sudoku
Map the eight attacks
Each cell has up to eight knight-move neighbours — placing a digit forbids it in all of them.
Great for the middle
Central cells reach the most neighbours, so anti-knight logic bites hardest there.
Combine with boxes
A digit already in a box plus its knight exclusions often leaves a single legal cell elsewhere.
Frequently asked questions
- What is anti-knight sudoku?
- A sudoku where cells a chess knight's move apart cannot share the same digit.
- How many knight-move neighbours does a cell have?
- Up to eight, fewer near the edges and corners of the grid.
- Does anti-knight replace normal rules?
- No, it adds to them — rows, columns, and boxes still each hold 1–9.
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