Samurai Sudoku

Five 9×9 grids woven into one giant puzzle. A central grid overlaps four corner grids, each sharing a 3×3 box with the middle — so solving one grid helps unlock the next. Same clean logic you know, on a much bigger, more absorbing board. Free, in your browser, with three difficulty levels.

What Samurai Sudoku is

Samurai Sudoku — also known as Gattai-5 or Five-Grid Sudoku — arranges five standard Sudoku grids in the shape of an X. Four grids sit in the corners and one sits in the middle, and where they meet they share a complete 3×3 box. Those shared boxes are the whole point: a number you place in the centre instantly becomes a clue in a corner grid, and vice versa. It is not five separate puzzles side by side — it is one connected puzzle that happens to have five overlapping sets of rules.

How to play

Every one of the five grids must follow the ordinary Sudoku rule: each row, each column and each 3×3 box contains the numbers 1 to 9 exactly once. The trick is that the four overlap boxes belong to two grids at the same time, so each entry there has to be legal for both. Tap a cell, pick a number, and let the shared boxes carry information across the board. Because each puzzle is generated with a single guaranteed solution across all five grids, you can always finish by logic alone.

A smart way to start

The fastest way into a samurai is through the overlaps. The four shared boxes each sit inside two grids, so they usually have the most constraints and resolve first. Solve the centre outward, lean on a corner grid whenever it is nearly done, and keep glancing at the shared boxes — every number you fix there does double duty. Work in bursts on whichever grid is most complete, and the puzzle steadily opens up.

Tips for your first samurai

• Treat the four shared boxes as your anchors — progress there ripples into two grids at once.
• Finish nearly-complete rows, columns and boxes first, exactly as in classic Sudoku.
• On a phone, scroll the board sideways; it is most comfortable on a tablet or desktop.
• Stuck on one square? The Hint button fills in one correct cell to get you moving again.

Everything you expect

• Three difficulty levels, a solve timer and a mistakes counter.
• Undo, erase and a one-cell hint, plus conflict highlighting across all five grids.
• Your game is saved automatically, and the board follows the site's light or dark theme.

Pacing a bigger puzzle

A samurai is a longer sit than a single grid, and the solvers who enjoy it most treat it that way. There is no prize for racing: because every shared box feeds two grids, a careful placement early on saves you far more time later than a hasty guess ever could. Many players solve a samurai in sessions — the game saves automatically, so you can fill the centre and one corner over a coffee, close the tab, and pick up the far corners tomorrow. If a grid stalls, move to a different one; progress there almost always loosens the box it shares with the grid that had you stuck. The puzzle rewards patience and a steady eye on those four overlaps more than raw speed.

Why five grids beats one big one

At first glance a samurai can look like five ordinary puzzles printed close together, but the overlaps change everything. Each shared box is doing two jobs at once, so the number of genuine deductions available to you is higher than in a single grid — and the satisfaction of watching a placement in the centre cascade out into a corner is something a lone 9×9 simply cannot offer. It is the same logic you already know, scaled up into something that feels more like an unfolding landscape than a single test.

If you like big puzzles

Enjoy the extra scale? Killer Sudoku adds arithmetic cages, Diagonal Sudoku (Sudoku X) adds two diagonal constraints, and Flower Sudoku reshapes the regions into petals. For the pure original at any level, the classic board and Expert Sudoku are always a tap away.