A LITTLE FOCUS. A FRESH START.
Play Renban Sudoku
Play Renban Sudoku free online. Purple lines hold consecutive sets in any order, with five difficulty levels and separate saved puzzles.
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The game loads here. Choose a difficulty to start or resume a puzzle.
LEARN THE TWIST
How to play Renban Sudoku
Renban requires consecutive values across the whole line, not increasing order along the path. This makes it different from a thermometer.
The rules
Fill each row, column, and 3×3 box with 1–9, without repeats. Each purple line contains consecutive, nonrepeating digits in any order.
A useful first move
The largest and smallest digits on a line differ by its length minus one. If a three-cell line contains 2, its set must be 1–2–3 or 2–3–4.
A three-cell purple line can contain 5, 3, 4: it uses the consecutive set 3–4–5. It cannot contain 3, 4, 6 because the set skips 5, or 3, 4, 4 because a digit repeats.
SOLVE IT STEP BY STEP
Complete the consecutive set, in any order
A Renban line specifies a set of different consecutive digits. It does not specify their order along the purple path. Think about the smallest and largest values the whole line can contain, then use the grid to arrange that set.
- Last line cell
- 3
Use the line’s length.
Three cells need three different consecutive values. The largest and smallest must differ by exactly two once the line is complete.
Fit the known endpoints of the set.
The line already contains 2 and 4. The only three-number consecutive set containing both is {2, 3, 4}.
Supply the missing member.
The last cell is 3. The path reads 2, 4, 3, which is valid: Renban controls the set, not whether each step goes up.
Reduce several possible intervals
A four-cell line containing 5 could initially use 2–5, 3–6, 4–7, or 5–8. If a 2 is later placed on that same line, only 2–5 remains. Even without an exact placement, a candidate eliminated from every cell of an interval can make that entire interval impossible.
Common mistakes to avoid
- Consecutive does not mean sorted along the line. Bends and path direction do not change the rule.
- A line cannot repeat a digit, even when the repeating cells would be allowed by ordinary Sudoku.
Try the reasoning yourself
A four-cell Renban line contains 3 and 6. Which set must it use?
Show the answer and why
It must use {3, 4, 5, 6}. Four consecutive values that include both 3 and 6 have no room to extend below 3 or above 6. Their positions still depend on the other rules.
Controls, difficulty, and saved games
Choose Beginner, Easy, Medium, Hard, or Expert above. Select an empty cell, then tap a number or use your keyboard. Notes let you pencil in candidates; three hints are available. Three mistakes end the puzzle.
Every mode and difficulty keeps a separate save in this browser. You can switch puzzles and return to your place. Clearing site data removes these saves; they do not sync with another device or the iPhone app. Settings include night mode and optional automatic cell advancement.
Correct entries earn points. High scores are stored by mode and difficulty and update only when beaten; completed-puzzle count and day streak are shared.
FIFTEEN WAYS TO PLAY
Explore all Sudoku modes
A familiar grid, a different kind of logic. Every mode is free to play in your browser.