Medium Renban Sudoku

Digits on each purple line form a set of consecutive digits in any order. The line's length tells you the range.

Easy Medium Hard Expert

Renban Sudoku at medium difficulty. Consecutive set analysis combined with box uniqueness — overlapping lines unlock each other.

3
1
5
1
8
6
9
6
7
1
8
9
5
1
2
1
3
9
8
9
4
1
3
2
9
4
7
9
7
8
4
2
Mistakes
0/3
Score
-
Time
00:00
Try Hard Renban Sudoku →
Progress0%

What is Renban Sudoku?

Difficulty
★★★★☆
4/5
Constraint Type
Line Constraints
Typical Givens
20–28
Avg. Solve (Medium)
22 min

Solving Techniques for Medium Level

Technique Description Level
Length-Based Range A Renban line of length L must contain L consecutive integers. The starting value is between 1 and 10−L, giving 10−L possible ranges. Beginner
Shared Cell Intersection If two Renban lines share a cell, that cell's value must fit both lines' consecutive ranges. Intersect the ranges to find valid values. Intermediate
Single-Range Reduction When a Renban line's valid range reduces to a single starting value, all cell values are fully determined (in some order). Intermediate

Master these, then take on Hard Renban Sudoku to learn Advanced techniques.

Techniques to Master at Medium

  • Hidden Singles technique — When a line's run is pinned (say 4–7), digits outside the run are evicted from every line cell — the crossing rows must place those digits off-line, creating hidden singles.
  • Obvious Pairs technique — Two cells of a renban line restricted to the run's two end values form a pair; the consecutive-set rule means spotting one such pair usually fixes the whole run.

Average Solve Time by Difficulty

Easy
10 min
Medium
22 min
Hard
42 min
Expert
72 min
Want a full walkthrough of rules, strategies, and solving steps? How to Play Renban Sudoku →

Related Variants

German Whispers

The mirror image of renban logic: lines that forbid close digits instead of requiring a consecutive run.

Palindrome Sudoku

Another line whose meaning is about the set of digits on it — here the line must read the same in both directions.

Between Lines Sudoku

Swaps the consecutive-run rule for a bounded-range rule anchored by two endpoint circles — kindred range reasoning.

Frequently Asked Questions — Medium Renban Sudoku

What is the key technique in medium Renban Sudoku?
Renban set analysis: for each line, list all possible consecutive sequences of the right length. Then check which digits from each sequence are eliminated by the row, column, or box constraints of the line's cells. This narrows the possible sequences and often forces individual cell placements.
How does line length affect difficulty in medium Renban?
Longer lines have more possible consecutive sequences, making them harder to pin down initially. Shorter lines have fewer sequences and are more immediately constrained. In medium puzzles, combining deductions from short lines with box logic often breaks open longer lines.
What happens when two renban lines share a cell?
The shared cell must belong to a valid consecutive sequence for both lines simultaneously. This intersection can be very powerful — the digit in the shared cell must satisfy both sequences, often leaving only one or two possibilities.
How long does medium Renban Sudoku take?
Most players finish medium Renban Sudoku in 15–30 minutes. The solving rhythm typically involves alternating between renban set analysis and standard Sudoku techniques as each unlocks the other.
Can a renban line span multiple 3x3 boxes?
Yes, and this is common. When a line crosses a box boundary, the consecutive set must still be satisfied, but the uniqueness constraint for each box still applies independently. This interaction between the line constraint and box uniqueness is a key source of deductions.

More questions? See the full Renban Sudoku guide.