Samurai Sudoku

Samurai Sudoku, also called Gattai-5, joins five standard 9 by 9 Sudoku grids in a cross-shaped layout. Four corner boxes are shared between the center grid and an outer grid. Every shared entry must satisfy both boards, so a deduction in one region can open a second region. This page presents five connected practice grids with the familiar row, column, and box controls.

1. Start with a row, column, or box that has many given digits.
2. Select an empty cell and choose a number from 1 through 9.
3. Reject a number that already appears in the cell's row, column, or 3 by 3 box.
4. After each placement, inspect the linked corner region and transfer the new constraint.
5. Continue until all five grids contain every digit exactly once in every row, column, and box.

• Each constituent board follows standard Sudoku rules.
• Digits 1 through 9 appear once in every row, column, and 3 by 3 box.
• A shared 3 by 3 corner belongs to two boards at the same time.
• A legal move for one board must remain legal for the other board sharing that cell.
• The puzzle is logic based. Guessing can hide a contradiction and waste time.

• Solve singles in the center and corners first, then revisit every overlap.
• Write candidate sets in a notebook when a box has several possible entries.
• Use pairs when two cells in one unit share the same two candidates.
• Scan across an overlap after every strong placement. The second board may have a forced digit.
• Keep an eye on rows that cross crowded regions. They often connect two local deductions.

• Classic Sudoku: One 9 by 9 grid uses the same row, column, and box rules without linked boards.
• Sudoku X: Sudoku X adds two long diagonal units to a single 9 by 9 board.

• Overlapping grids multiply the satisfaction of each correct placement.
• A single deduction can cascade across two boards at once.
• The cross layout gives the puzzle a distinct visual identity.
• Standard Sudoku skills transfer directly to the larger format.
• Solving all five grids delivers a deeper sense of completion.

Play Samurai Sudoku online for free on Clasica Games. Five overlapping 9 by 9 grids load in your browser with cell selection and candidate marking. Start with the center grid, work into the shared corners, and watch deductions cascade across boards. No download needed. Pick a cell and place your first digit.

Samurai Sudoku stretches classic Sudoku across five linked grids. Solve the overlaps first, let deductions travel between boards, and fill every row, column, and box. Start a free puzzle and see how far one placement can travel.

• Samurai Sudoku rules