Expert Samurai Sudoku
Five overlapping 9×9 grids share corner boxes. Solve all five simultaneously — each shared box belongs to two grids at once.
The hardest five-grid Samurai puzzle on Sudoku.by. Intricate shared-box interactions — multi-grid forcing chains required. No guessing.
Score
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Mistakes
0/3
Time
00:00
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Expert · Samurai Sudoku · 5 sub-grids
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How to play Samurai Sudoku
Five overlapping 9x9 Sudoku grids. Each sub-grid must independently satisfy standard Sudoku rules (1-9 in each row, column, and box). Where two sub-grids share a 3x3 corner box, that box must satisfy both grids simultaneously. Solve sub-grids with the most clues first, then use shared boxes to unlock others.
How to Play Samurai Sudoku →
What is Samurai Sudoku?
Difficulty
★★★★★
5/5
Constraint Type
5 Overlapping Grids
Typical Givens
~30 per sub-grid
Avg. Solve (Expert)
240 min
Solving Techniques for Expert Level
| Technique | Description | Level |
|---|---|---|
| Sub-Grid Independence | Each of the five 9×9 sub-grids satisfies standard Sudoku rules independently. Solve each one using all standard techniques. | Beginner |
| Overlap Box Exploitation | The four corner boxes where sub-grids meet are shared between two grids. Any digit placed in a shared box eliminates that digit from two sub-grids at once. | Intermediate |
| Cross-Grid Cascade | Completing a corner box in the central grid forces values in the corresponding corner grid's box, which may cascade further through that grid. | Intermediate |
| Shared Box Forcing | When a shared box is nearly complete, use both sub-grids' row and column constraints to force the remaining digits. | Advanced |
| Global Number Counting | Across all five sub-grids, each digit 1–9 appears 5×9=45 times total. This global count can confirm placement decisions near the end. | Advanced |
Techniques to Master at Expert
- X-Wing technique — Expert samurai grids are gated: each sub-grid stalls until an overlap delivers a digit, and X-Wings inside the centre grid are usually what start that delivery.
- Swordfish technique — Run Swordfish scans per sub-grid in rotation — expert samurai puzzles typically hide one fish in the centre grid whose eliminations cascade outward through all four overlaps.
Average Solve Time by Difficulty
Easy
45 min
Medium
90 min
Hard
150 min
Expert
240 min
Want a full walkthrough of rules, strategies, and solving steps?
How to Play Samurai Sudoku →
Related Variants
Jigsaw Sudoku
A different geometry challenge in one grid — region shapes that snake instead of grids that overlap.
Chaos Construction
For solvers who enjoyed scale, chaos offers depth: deduce the hidden region borders while solving.
Hyper Sudoku
Overlapping regions condensed into a single 9×9 — four windows that share cells with the standard boxes.
Frequently Asked Questions — Expert Samurai Sudoku
More questions? See the full Samurai Sudoku guide.