Samurai Sudoku combines five 9×9 Sudokus in a cross-shaped layout. Four corner grids overlap the center grid by one 3×3 box each, producing 369 distinct cells rather than 405.
What is Samurai Sudoku?
Samurai Sudoku is a five-grid puzzle in which four corner 9×9 Sudokus overlap a central Sudoku at four 3×3 boxes. Every individual grid obeys classic row, column and box rules. A digit placed in an overlap belongs to both grids, so deductions should be transferred immediately across the shared region.
How is a Samurai Sudoku laid out?
Imagine one standard Sudoku in the center. Place four more grids around it—top-left, top-right, bottom-left and bottom-right—so each corner grid shares its nearest 3×3 box with one corner box of the center grid.
The overlap is not duplicated. A printed digit there is the same cell for both grids, and it must satisfy the row, column and box rules of each grid containing it.
What is the best order for solving Samurai Sudoku?
Begin in whichever outer grid has the most givens or easiest singles. Record placements in its shared box, then switch to the center grid and use them there. Do not insist on completing one whole grid before looking elsewhere; the puzzle is designed for information to travel.
A reliable cycle is outer grid, overlap, center, opposite overlap, next outer grid. After a breakthrough, revisit every grid touching that cell or box.
Why are overlap boxes so important?
An overlap box belongs to two grids. Its nine cells participate in two sets of rows and two sets of columns while sharing one box constraint. A candidate removed by a row in the corner grid is also gone when the center grid considers that physical cell.
Hidden singles can emerge from either perspective. A digit may have one position left in the center row, fixing a cell that then completes an outer-grid column.
How do you keep Samurai Sudoku candidates organized?
- Use consistent labels for the five grids.
- Write candidates once in shared cells, not separately for each grid.
- Highlight overlap boxes before solving.
- After every shared placement, update both grids immediately.
- Use a larger printout or zoom level so notes remain readable.
The difficulty is often bookkeeping rather than a new logical technique. Classic singles, subsets, locked candidates and fish still apply inside each constituent grid.
Is Samurai Sudoku just five separate puzzles?
No. If they were independent, you could solve them in any order. The shared cells couple their candidate states, and some intended deductions require moving between grids.
Our game / Story-led deduction
Want each placement to reveal part of a mystery?
Detective Sudoku is not classic Sudoku. It replaces digits and boxes with suspects, rooms and truthful spatial clues while retaining one suspect per row and column. Its real hints identify the clue behind a deduction instead of giving you the answer or solution.
See what makes Detective Sudoku different →Frequently asked questions about Samurai Sudoku
How many grids are in Samurai Sudoku?
Five standard 9×9 grids: four outer grids and one central grid.
How many cells does Samurai Sudoku have?
The five grids contain 369 distinct cells because four 3×3 boxes are shared.
Do overlap cells follow both grids?
Yes. Each shared cell must satisfy every row, column and box belonging to both grids.
Should you solve the center first?
Not necessarily. Start where moves are available and transfer every overlap deduction.