How to Play
Learn the basics of each Club Sudoku puzzle, how to use the game controls, and a few tips for getting more out of your games.
The Basics
Classic 9×9 Sudoku
Fill the 9×9 grid so that every row, every column, and every 3×3 box contains the digits 1 through 9, each appearing exactly once. No digit can repeat in any row, column, or box.
6×6 Sudoku Lite
The same basic Sudoku idea on a smaller 6×6 grid using the digits 1 through 6 and 2×3 boxes. It makes for a shorter game while keeping the familiar Sudoku logic.
Killer Sudoku
Killer Sudoku adds shaded cages with target sums. The digits inside a cage must add up to the total shown for that cage, while the standard row, column, and box rules still apply.
Hard Mode
Hard Mode gives you fewer starting numbers, so there is less information on the board when you begin. Hints are available, but Hard Mode provides less visual assistance while you play.
Daily Challenge
The Daily Challenge is the same Classic 9×9 puzzle for everyone each day. Each day has its own puzzle name and theme, and previous Daily Challenges can be played again through the Archive.
Using the Game
Number pad: Tap a cell on the grid to select it, then tap a number on the pad to place it. Tap the same number again to clear it.
Notes: Tap Notes to switch to pencil mode. In pencil mode, tapping a number adds it as a small candidate note inside the cell rather than placing it as an answer. Tap Notes again to return to normal entry.
Undo: Removes your last action. Tap multiple times to undo several moves.
Check: Highlights any incorrect entries in red so you can find and fix mistakes.
Hint: Fills in one correct number for you. Puzzles solved without hints qualify for the Hall of Fame.
Pause: Stops the timer and hides the grid until you resume. Useful if you need to step away.
New: Starts a fresh puzzle at your current difficulty setting.
Difficulty: Choose Easy, Medium, Hard, or Expert from the right side panel. The difficulty affects how many numbers are given at the start.
Completing a Puzzle
When you fill in the last correct number, the puzzle is complete. A celebration screen shows your time, number of hints used, and number of mistakes. Puzzles completed without any hints are recorded in your personal Hall of Fame with your best time.
From the completion screen you can share the puzzle with a friend — they will receive a link that loads the exact same puzzle so they can try to beat your time. Tap Review Game to return to the completed board, or New Puzzle to start a fresh game.
Strategies
- Fill in the only option. When a cell can only hold one possible number after checking its row, column, and 3×3 box — fill it in immediately.
- Track a number across rows and columns. Often a number has multiple placement options. Find a row or column that is nearly complete and needs that particular number — if the empty cell falls within the right 3×3 box, you have your answer.
- Use a nearly complete box. Since every 3×3 box must contain all 9 numbers exactly once, count the numbers already placed in that box — the missing one belongs in the empty cell. Tap ✓ Check to confirm.
- Start with the most common numbers. When starting a new puzzle, glance at the number pad — some numbers may already be nearly complete on the board. Placing that final missing number first can open up a row and column, making the rest of the puzzle easier.
Club Members' Tips
- Start with the easy numbers. Look for rows, columns, or boxes that already have many numbers filled in — those are the easiest places to start.
- Check the whole area. Before placing a number, scan its entire row, column, and box to make sure it doesn't already appear.
- Don't rush. If you get stuck, move to another part of the puzzle and come back. A fresh look often reveals what you missed.
- Use Notes. When you're not sure about a number, use pencil mode to mark your candidates. Narrowing down possibilities is often the key to a breakthrough. Working through them can sometimes finish the game without needing the Hint button at all.
- Use a Hint when you need one. There's no rule that says you have to solve every puzzle without help. Save the no-hint runs for when you're feeling confident.
- For Killer Sudoku: Start by looking at cages with very small or very large sums — these have fewer possible digit combinations and are the easiest to solve first.
Sharing a Puzzle
Club Sudoku lets you share any puzzle with a friend directly from the game. On the right side of the game page, tap Share with a friend to share the current puzzle at any time. You can also share from the completion screen after finishing a puzzle.
On most phones, tapping Share opens your device's share menu — you can send the puzzle link directly through Messages, WhatsApp, email, or any other app. On desktop or some browsers, the link is copied to your clipboard instead. Just paste it wherever you want to send it — in a text, email, or chat — and your friend can tap the link to open the exact same puzzle.
