Renban Sudoku
Purple lines must contain consecutive digits in any order
Renban Sudoku is fully playable. Choose a difficulty and start solving.
Each purple line carries a block of consecutive digits — any order, no gaps, no repeats. A line's length immediately limits which runs can fit, and crossing lines must agree where they meet. Set-based thinking rather than arithmetic; medium-hard in practice.
For the complete rules, worked examples and solving techniques, read the full How to Play Renban Sudoku guide.
Like all Sudoku variants, Renban Sudoku builds on the classic 9×9 foundation. Every row, column, and 3×3 box must contain each digit from 1 to 9 exactly once. The variant constraint is added on top of these standard rules, never replacing them.
If you're new to Sudoku, start by learning the basic rules and techniques before attempting variants.
Techniques Useful for This Variant
| Technique | How it applies |
|---|---|
| Pencil Marks / Notes | Essential for tracking candidates alongside the variant constraint |
| Obvious Singles | Cells narrowed to one candidate by the combined constraints |
| Hidden Singles | Digits with only one valid cell in a unit after variant elimination |
| Pairs and Triples | Locked candidates exposed by the additional constraint |