Medium Diagonal Sudoku
Ready to sharpen your skills? Medium Diagonal 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 Diagonal 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 Diagonal Sudoku who want to build their pattern recognition.
Difficulty overview
About Diagonal Sudoku
In Diagonal Sudoku, the standard 9×9 rules apply — but with one powerful extra constraint: both main diagonals (top-left to bottom-right, and top-right to bottom-left) must each contain every digit from 1 to 9 exactly once. This extra constraint typically makes the puzzle easier to solve since diagonals act as two extra units for elimination.
Solving Techniques for Medium Level
| Technique | Description | Level |
|---|---|---|
| Diagonal as a Unit | Treat each diagonal exactly like a row or column — every digit 1–9 appears exactly once. Standard scanning and counting apply. | Beginner |
| Diagonal–Box Interaction | When a digit on a diagonal is confined to one box segment, eliminate it from the rest of that box. | Intermediate |
| Diagonal Naked Pairs | If two cells on a diagonal share the same two candidates, eliminate those values from all other diagonal cells. | Intermediate |
Master these, then take on Hard Killer Sudoku to learn Advanced techniques.