Easy Samurai Sudoku

Score
-
Mistakes
0/3
Time
00:00
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New Game
Easy · Samurai · 5 sub-grids0%
How to play Samurai Sudoku
Five overlapping 9×9 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 3×3 corner box, that box must satisfy both grids simultaneously. Solve sub-grids with the most clues first, then use shared boxes to unlock others.

About Samurai Sudoku

Difficulty
★★★★★
5/5
Constraint Type
5 Overlapping Grids
Typical Givens
~30 per sub-grid
Avg. Solve (Medium)
90 min

Samurai Sudoku consists of five interlocking 9×9 grids arranged in an X shape — one central grid and four corner grids, all sharing a 3×3 box where they overlap. Each of the five sub-grids must independently satisfy standard Sudoku rules. Solving one sub-grid often provides clues that unlock another. The complete puzzle spans a 21×21 grid.

Solving Techniques

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

Average Solve Time by Difficulty

Easy
45 min
Medium
90 min
Hard
150 min
Expert
240 min

Frequently Asked Questions

How many sub-grids are there?
Five: one central grid and four corner grids, all arranged in an X or plus shape.
How many cells are in a Samurai puzzle?
369 valid cells total — five 9×9 grids with four shared 3×3 corner boxes subtracted.