Master Sudoku

Master Sudoku offers 4x4, 6x6 and 9x9 puzzles on a wooden board, each available at Easy, Normal, Hard and Expert. Mistakes matter more than speed: the timer only records your attempt, while the third wrong entry ends the puzzle.

How to play Master Sudoku

• Tap an empty square, then tap the number you want to place there.
• Fill the whole grid without repeating a number in any row, column or outlined box. Completing the grid solves the puzzle.
• A correct entry stays on the board. A wrong one is removed and counts as a mistake.
• Each new board starts with three hints. Select an empty square before tapping the hint button, and the game fills that square correctly.
• The settings can hide the timer or turn off the matching-number highlight. There is no separate score.
• Your unfinished board, elapsed time, remaining hints and mistake count are saved so you can resume later.

Tips

• Leave the matching-number highlight on while learning a larger board. Selecting a placed number shows every copy, which makes it easier to spot a row or box still missing that number.
• If you already have two mistakes, use a hint on an uncertain square instead of risking the entry that would end the puzzle.

Which board can you solve without using a hint?