How to play Sudoku
Rules, modes, and shortcuts at a glance.
The rules
Fill every empty cell so that each row, each column, and each box contains every required digit exactly once. Morniura Sudoku supports 4×4 (2×2 boxes), 6×6 (2×3 boxes), and 9×9 (3×3 boxes) boards.
Learn in more detail
Rules, beginner flow, and advanced techniques are split into topic pages.
Two play modes
New Game
Choose a board size and difficulty (easy / normal / hard / expert) and start a fresh puzzle. Every puzzle is prepared with exactly one solution.
Daily Sudoku
Everyone gets the same puzzle for the same date and (board, difficulty) combination. Completed runs are recorded on the daily leaderboard.
Keyboard shortcuts
1–9: enter a number · Arrow keys: move · N: memo mode · H: hint · ⌘Z: undo · Space: pause · Backspace/Delete: clear
Timer and leaving the page
For regular New Game runs, leaving the page before completion restores the puzzle in a paused state. For non-battle runs, use Reset on the play screen to restart the same puzzle from the beginning. In Daily Sudoku and Challenge runs, brief time away still counts so competitive records stay fair. Daily Sudoku resets to today's puzzle when the date changes or a run passes 24 hours.
Scoring
Live score rises as you fill empty cells. On completion the final score is:
Final = (Live − Time penalty − Mistakes × 100) × Clean Run bonus
Live score
Empty cells × per-cell points. Per-cell value is set by difficulty and board size so every board carries a meaningful score range. Hint-filled cells count the same as any other.
| 4×4 | 6×6 | 9×9 | |
|---|---|---|---|
| Easy | 600 | 800 | 1000 |
| Normal | 900 | 1200 | 1500 |
| Hard | 1500 | 2000 | 2500 |
| Expert | 2400 | 3200 | 4000 |
Time penalty
Per second: easy 0.5 · normal 1 · hard 1.5 · expert 2 points. The total is capped at 50% of the live score, so a long game still keeps at least half.
Mistake penalty
Every wrong cell entry counts as one mistake and subtracts 100 points. Classic keeps wrong entries marked; Challenge shows them briefly, then clears them.
Clean Run bonus
Finish with zero mistakes and the final score is multiplied by ×1.2. Hint and memo usage do not affect the bonus.
Hints and score
Hints do not reduce your score. Daily runs with one or more hints are listed in Assisted ranking, while only zero-hint runs enter Official ranking.
Fair play
The solution is never shown on the play screen. When you finish, you only see whether the board is complete and which cells need another look; failed submissions never reveal the correct values. Unusually fast completions are excluded from ranking.