Samurai Sudoku
Samurai Sudoku joins five 9×9 grids into one giant puzzle: four corner grids plus a central grid, overlapping so each corner grid shares a 3×3 box with the centre. Every one of the five grids follows normal Sudoku rules — and the shared boxes mean a digit you place in an overlap counts for two grids at once. Also known as Gattai-5. Play a board below, then read how the overlaps work.
How to play Samurai Sudoku
- Five grids — the board is five 9×9 Sudokus: top-left, top-right, bottom-left, bottom-right and centre.
- Normal rules each — within every grid, each row, column and 3×3 box must contain 1–9 exactly once.
- Shared corners — each corner grid overlaps the centre by one 3×3 box; those nine cells belong to two grids at the same time.
- Use the overlaps — a digit in a shared box must satisfy both grids, so the corners are where the puzzle links together.
- Play it — tap a cell then a number, ⌫ to clear. Every board has one solution reachable by logic.
What is Samurai Sudoku?
Samurai Sudoku (also called Gattai-5) is five overlapping 9×9 Sudoku grids arranged in an X: four in the corners and one in the middle, with each corner grid sharing one 3×3 box with the central grid. Each grid is a complete Sudoku in its own right, so you’re really solving five linked puzzles at once. It’s a favourite for players who want a longer, meatier sit-down than a single 9×9.
How the overlaps help you
The shared corner boxes are the key: a digit placed there has to work for two grids at once, so progress in one grid feeds straight into its neighbour. When a corner grid is nearly solved, the overlap hands the centre grid a block of known cells — and vice versa. Good Samurai solving bounces between the grids through those corners, rather than finishing one grid in isolation.
Easy and hard Samurai boards
Easy boards give more starting digits across all five grids; hard boards give fewer, so you lean harder on the overlaps to break in. Every board is generated to have a single solution reachable by pure logic — no guessing — and tapping New deals a fresh one. On a phone it’s a big grid, so turning sideways or zooming can help.
Samurai Sudoku: FAQ
What is Samurai Sudoku?
Five overlapping 9×9 Sudoku grids — four corners plus a centre — where each corner grid shares a 3×3 box with the central grid. Each grid follows normal Sudoku rules. It’s also called Gattai-5.
How do the overlapping boxes work?
The four 3×3 boxes where a corner grid meets the centre are shared: those nine cells belong to two grids at once, so a digit there must be valid in both. They’re where the five grids link together.
Is it harder than normal Sudoku?
It’s bigger, not necessarily trickier cell-by-cell. The overlaps actually help — solving one grid feeds the next. It just takes longer because there are five grids to finish.
Is there always one solution?
Yes. Every Samurai board here is generated and checked to have exactly one solution reachable by logic alone.
Is it free to play?
Yes — it plays free in your browser on phone, tablet and desktop, no download or sign-up. Tap New for a fresh board any time.