Consecutive Sudoku
Classic sudoku with markers showing which adjacent cells differ by exactly one.
What is consecutive sudoku?
Consecutive sudoku adds inline markers. usually small dots or bars. between adjacent cells whose digits differ by exactly one. Some variants mark only adjacent consecutive pairs; stricter versions mark every consecutive pair and explicitly mark non-consecutive pairs too.
Rules
- Standard 9×9 sudoku rules apply.
- A marker between two adjacent cells means the digits in those cells differ by exactly 1 (e.g. 4 next to 3 or 4 next to 5).
- Absence of a marker means the two digits do NOT differ by 1 (in the strict variant).
Tips
- Marked pairs strongly constrain candidate sets. start with chains of three or more markers.
- A marker forces one cell's value to be exactly one more or one less than its neighbour.
- Pencil marks make consecutive sudoku much more solvable.
Related variants
- Even-Odd Sudoku, Classic sudoku with a constraint on which cells hold even or odd digits.
- Diagonal Sudoku (X-Sudoku), Classic sudoku plus a constraint on both main diagonals.
- Killer Sudoku, Sudoku meets killer-style arithmetic: every dotted region sums to its total.
- Classic sudoku for comparison
Consecutive Sudoku FAQ
What does the marker mean exactly?
It means the two adjacent cells contain consecutive digits. values that differ by 1.
Do unmarked adjacent cells have any constraint?
In the strict variant, yes: they must NOT differ by 1. In the loose variant, an absent marker carries no information.
Sudokly uses which variant?
We use the strict variant. Markers are exhaustive: a marker means consecutive, and no marker means non-consecutive.
Are markers shown on all four sides of each cell?
Only between adjacent cells in the same row or column. diagonal neighbours are not marked.
Is consecutive sudoku harder than classic?
Roughly the same difficulty at the same clue count, but it solves very differently because the chain logic dominates.