🔷 How to play Even Sudoku
By Miguel Arechaga
Even Sudoku is the twin variant of Odd Sudoku. It adds a parity clue to the board: some cells appear shaded (often with a square) and indicate that only an even number can go there. It's a very accessible variant and a great way to practice elimination-based reasoning. Here are the rules and tips.
What is Even Sudoku?
It's a standard 9x9 sudoku where certain cells are marked as even. Only the numbers 2, 4, 6 or 8 can be placed in those cells. The remaining cells have no parity restriction and accept any number. The rest of the sudoku rules stay intact.
Rules and how to play step by step
- The sudoku rules apply: 1 to 9 without repeats in each row, column and 3x3 box.
- In the shaded cells (with a square) you can only write even numbers: 2, 4, 6 or 8.
- Unmarked cells accept any number. Every puzzle has a unique solution.
Tips to solve Even Sudoku
- There are only four even numbers: 2, 4, 6 and 8. A shaded cell cuts its candidates significantly, so it tends to solve sooner.
- Push the odd numbers into place: in a row, column or box with several shaded cells, the odd numbers (1, 3, 5, 7, 9) are forced into the unmarked cells.
- If a region has exactly four shaded cells, those four split up exactly the four even digits.
- Combine parity with the classic elimination techniques to move faster.
How it differs from regular sudoku
Compared to classic sudoku, Even Sudoku adds parity information that acts as an extra clue. It's the perfect companion to Odd Sudoku: same rules, opposite parity. If you enjoy variants with additional restrictions, you'll also enjoy Sudoku X (Diagonal Sudoku).
