RULES · HOW TO PLAY
How to play Sudoku
Sudoku is a logic puzzle, not a math test. Fill empty cells so rows, columns, and boxes never repeat the same digit.
The basic rule
Classic 9×9 Sudoku uses the digits 1 through 9 once in every row, column, and 3×3 box. Morniura also supports 4×4 with 2×2 boxes and 6×6 with 2×3 boxes.
Where to start
Start with the row, column, or box that already has the most digits. When only one or two numbers are missing, candidates shrink quickly.
- Scan rows with the fewest empty cells.
- Remove candidates already present in the same column.
- If a box has only one legal place for a digit, fill it.
Playing on Morniura
The browser never receives the solution. You can enter values freely, but the server verifies completion before a score is recorded.
Practice order
- Pick a boardStart with 4×4 or easy 9×9 while learning the rule.
- Find a crowded unitUse a row, column, or box with many givens to reduce candidates.
- Place forced cellsFill cells with one remaining candidate and rescan nearby units.
- Submit for verificationOnce the board is full, the server checks the final grid.
Fill your first cell
Step 1 of 4
The smallest board, 4×4. Almost everything is filled — only row 1 column 1 is blank. Let's apply the rules to find the answer.