I’ve been asked a few times to post some Samurai sudoku solving tips. Well – there aren’t any special tips that apply exclusively to Samurai. Standard Sudoku rules apply, but to make things clear for newcomers, I’d like to give a brief set of instructions.
Rules of Samurai Sudoku
1. Each Samurai Sudoku puzzle consists of 5 overlapping classic 9×9 Sudoku sub-puzzles.
2. Each 9×9 sub-puzzle must be solved according to the rules of Sudoku: each row, column and 3×3 box must contain all digits from 1 to 9; therefore, digits cannot be repeated.
3. Each Samurai Sudoku puzzle has one solution only.
1. DO NOT ATTEMPT to completely solve each sub-puzzle as an individual puzzle!
2. Each 9×9 sub-puzzle when solved individually could have more than one solution.
3. Never resort to guessing my puzzles can be solved using deduction logic.
1. Work on the puzzle as a whole.
2. Start with one sub-puzzle and solve as many cells as you can, until you can’t go further (do not guess!)
3. Move on to the next sub-puzzle. Use clues from the previous sub-puzzle.
4. Repeat step 2 for that sub-puzzle.
5. Keep repeating steps 2-3-4 until you solve the whole puzzle!
6. Do not start with the center sub-puzzle. They usually have fewer clues than other sub-puzzles.
Usual classic Sudoku techniques are required to solve these puzzles: naked and hidden singles, naked and hidden subsets (pairs, triplets etc) and “row/column and box interactions”. For the hardest of puzzles X-Wing and Swordfish techniques might be needed.