🔗 How to play Non-Consecutive Sudoku

By Miguel Arechaga

Non-Consecutive Sudoku is a very elegant variant that adds just one new rule: consecutive numbers can't be neighbors. Simple as it sounds, this restriction applies across the entire board at once and opens up an enormous number of deductions. Here are the rules and a few tips.

What is Non-Consecutive Sudoku?

It's a standard 9x9 sudoku with one extra condition: two cells that touch along an edge (above, below, left or right) can't contain consecutive numbers. In other words, a 5 can't have a 4 or a 6 right next to it. Diagonals don't count; only orthogonal neighbors.

Rules and how to play step by step

1. The sudoku rules apply: 1 to 9 without repeats in each row, column and 3x3 box.
2. In addition, two neighboring cells (sharing an edge) can't be consecutive: their difference can't be 1.
3. You start with some clue cells and fill in the rest with logic. Every puzzle has a unique solution.

Tips to solve Non-Consecutive Sudoku

• Each number blocks two neighbors: placing a value removes the number right before and right after it as candidates for its adjacent cells.
• 1 and 9 are special: they only have one forbidden neighbor (2 and 8, respectively), so they tend to be easier to place.
• Look for chains: if you know two adjacent cells hold high numbers, they're likely alternating to avoid being consecutive.
• Combine the rule with the classic elimination techniques of sudoku.

How it differs from regular sudoku

Compared to classic sudoku, Non-Consecutive introduces a relationship between the values of neighboring cells, not just the ban on repeats. That completely changes how you reason. If you enjoy variants with extra restrictions, you'll also enjoy Anti-Knight Sudoku and Anti-King Sudoku.