Medium Anti-King Sudoku
Ready to sharpen your skills? Medium Anti-King Sudoku puzzles introduce interactions between the variant constraint and classic Sudoku techniques. You'll need to combine both skill sets to progress.
What to expect at Medium level
Medium Anti-King Sudoku puzzles require you to combine the variant constraint with standard Sudoku deduction - Naked pairs, hidden singles, and unit scans. The constraint is more tightly woven into the grid, so you'll need to think a few steps ahead.
Best suited for players comfortable with Easy Anti-King Sudoku who want to build their pattern recognition.
Difficulty overview
About Anti-King Sudoku
Anti-King Sudoku adds a chess-inspired constraint: cells that would be reachable in a single king move (orthogonally or diagonally adjacent) cannot share the same digit. This extends the non-repeat rule beyond rows, columns, and boxes to include diagonal neighbours, significantly tightening the constraint space throughout the grid.
Solving Techniques for Medium Level
| Technique | Description | Level |
|---|---|---|
| Diagonal Exclusion | The king constraint extends the exclusion zone to all 8 neighbours including diagonals. Apply diagonal exclusions before standard row/col/box logic. | Beginner |
| Corner Restriction | Corner cells (e.g., r1c1) only have 3 king-move neighbours. Start with corners and edges to build initial placements. | Intermediate |
| King-Chain Elimination | When a digit is placed, eliminate it simultaneously from all 8 surrounding cells. | Intermediate |
Master these, then take on Hard Killer Sudoku to learn Advanced techniques.