How to Play Consecutive Sudoku
Bars between cells mean those two digits are consecutive
The Rules
Standard Sudoku rules apply: fill every row, column, and 3×3 box with the digits 1–9, each appearing exactly once.
Consecutive Sudoku marks bars between pairs of adjacent cells. A bar means the two digits in those cells differ by exactly 1 — they are consecutive. When used with the negative constraint (no bar = not consecutive), this gives information about every adjacent pair in the entire grid, creating a powerful constraint network.
At a Glance
How to Solve Consecutive Sudoku
Common Questions
What is Consecutive Sudoku? ▾
Consecutive Sudoku is a variant where white bars appear between some adjacent cells. A white bar means those two cells hold digits that differ by exactly 1. Crucially, all consecutive adjacent pairs are marked — if there is no bar between two cells, they are guaranteed not to be consecutive.
How does the no-bar constraint work? ▾
Every adjacent pair that is NOT consecutive has no bar. This negative information is extremely powerful — it eliminates all consecutive digit pairs from unmarked cell boundaries. Experienced players apply no-bar eliminations as aggressively as the positive bar clues.
What pairs count as consecutive? ▾
Consecutive digits differ by exactly 1: 1&2, 2&3, 3&4, 4&5, 5&6, 6&7, 7&8, 8&9. The constraint applies to horizontally and vertically adjacent cells only — diagonal neighbours are not considered.
What is the best first move in Consecutive Sudoku? ▾
Look for long chains of consecutive bars — a chain of four bars forces four consecutive digits in those five cells. Also, digits 1 and 9 can only be consecutive with 2 and 8 respectively, so any cell surrounded by no-bar neighbours cannot hold 1 or 9 unless those specific partners are available nearby.
Is Consecutive Sudoku harder than regular Sudoku? ▾
At easy difficulty it is comparable to medium classic Sudoku. The bars and no-bars together provide a dense constraint web that makes early eliminations fast. Hard and expert puzzles become much more demanding as bar chains grow longer and interact with more rows, columns, and boxes.
How long does Consecutive Sudoku take to solve? ▾
Easy puzzles take 8–18 minutes. Medium puzzles run 18–35 minutes. Hard puzzles average 35–65 minutes and expert puzzles often exceed 90 minutes. Applying both bar and no-bar logic simultaneously is the key to efficient solving at all levels.