Extra Regions

Samurai Sudoku

Five overlapping 9×9 grids sharing corner boxes

Ready to Play!

Samurai Sudoku is fully playable. Choose a difficulty and start solving.

How Samurai Sudoku Works

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.

Standard Sudoku Rules Still Apply

Like all Sudoku variants, Samurai 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

TechniqueHow it applies
Pencil Marks / NotesEssential for tracking candidates alongside the variant constraint
Obvious SinglesCells narrowed to one candidate by the combined constraints
Hidden SinglesDigits with only one valid cell in a unit after variant elimination
Pairs and TriplesLocked candidates exposed by the additional constraint