What a samurai sudoku is
A samurai sudoku is five ordinary 9x9 grids arranged in a cross: one in the centre and one at each corner. The centre grid shares each of its four corner boxes with one of the outer grids, so the whole puzzle has 369 squares rather than 405. Every grid follows the usual rules on its own: each row, column and box holds the digits 1 to 9 once. The shared boxes belong to two grids at once, and that is where the fun starts, because a digit you place there has to work for both.
Taken as a whole, every samurai on this page has exactly one solution. An outer grid on its own may have several, because some of its clues only arrive through the shared box. That is by design, and it is why you cannot simply solve the five grids in isolation.
Who these are for
- Solvers who find a single 9x9 over too quickly and want five grids’ worth of work on one sheet.
- Anyone who enjoys the moment when a box filled in one grid unlocks a whole row in another.
- Teachers and puzzle club organisers who want one sheet that keeps a strong solver busy.
If you are new to sudoku, start with the easy sudoku page. A samurai is the same logic, just more of it.
How to solve one
- Start wherever a grid has the most given digits, usually an outer grid. Work through naked singles and hidden singles until you stall.
- When an outer grid stalls, move to the centre. Its corner boxes are the shared ones, and the centre grid’s rows and columns rule out digits there that the outer grid alone could not.
- Treat each shared box as the junction it is. A digit placed there is checked against two rows, two columns and one box, so it is usually the most constrained square on the sheet and often the next move.
- Keep circling. Progress in one grid feeds the next, and most samurai end with a satisfying run of singles across all five grids.
Difficulty levels
We grade the puzzle as a whole by the hardest technique it needs, the same scale as the rest of the site. An easy samurai can be solved with naked singles from the first square to the last, and keeps at least 170 of the 369 squares filled in. Medium adds hidden singles, pairs and box-line eliminations, with at least 135 given digits. Hard needs at least one triple, X-Wing, Swordfish or XY-Wing somewhere in the five grids, and never needs guessing. A second, independent solver confirms the single solution before a puzzle is published.
The two puzzles shown are today’s set, the same for everyone who visits today. Pick a level with the Difficulty control, and press New puzzles for two more from our stock of checked puzzles at that level.
Printing tips
Each samurai fills a page. The grid is 18 cm across, with squares just under 9 mm wide, so there is room for a pencil mark or two. The solutions print on their own page after the two puzzles, two to a page, with the given digits in bold. Download PDF gives you the same pages as a file, in A4 or Letter. Untick Include answers if you are handing the puzzles to someone else.
More puzzles
For a quicker solve, the hard sudoku page prints four 9x9 puzzles at the same level, and the daily sudoku gives you one new puzzle a day. The medium page is the right warm-up before a medium samurai.