Puzzle
Sudoku
Fill the 6×6 or 9×9 grid so every row, column and box holds each number once. Solve solo at four levels or race friends on the same puzzle.
Sudoku guide
The classic number puzzle in 6x6 and 9x9: solve solo at your level, or race friends through the very same grid.
How to play Sudoku
- Choose Play solo for a puzzle at your own pace, or Play online to race 2-6 players who all get the same puzzle.
- Pick a grid and a level. 6x6 (boxes of 2 rows by 3 columns): Easy 22, Medium 18 or Hard 14 given numbers. 9x9 (3x3 boxes): Easy 40, Medium 32, Hard 26 or Expert 22 given numbers.
- Tap an empty cell, then a number on the pad. The row, column and box of the selected cell light up, along with every cell holding the same number.
- Turn on Notes to pencil small candidate numbers into a cell. When you place a number, that note disappears from its row, column and box.
- Fill every cell so each row, column and box holds every number exactly once. Keyboard players can use the arrow keys, 1-9, Backspace and N for notes.
Rules
- Each row, each column and each box must contain every number from 1 to 6 (6x6) or 1 to 9 (9x9) exactly once.
- Every puzzle has exactly one solution, and the level is the exact number of given cells: fewer givens means less to go on.
- Numbers are checked as you place them. A wrong number turns red and counts as a mistake; the third mistake ends the puzzle (in a race, that player is out). Correct numbers lock in place.
- Solo puzzles give you 3 free hints; more hints use a hint helper from the Gem shop. A hint fills in the cell with the fewest possible numbers. Undo is free but does not take back a mistake.
- In an online race the first player to fill the whole grid wins. The race also ends when everyone is out, or after 10 minutes (6x6) or 30 minutes (9x9): then players who are still in rank ahead, and the most correct cells wins, with fewer mistakes breaking a tie. Races have no hints or undo, and other players never see your numbers.
Tips and strategy
- Look for a number that can only go in one place in a row, column or box; that is often quicker than looking for a cell with only one option.
- Start with the numbers that already appear most often: the count under each pad key shows how many are left.
- Use notes on harder levels. Two cells in a unit that can only hold the same two numbers rule those numbers out of the rest of the unit.
- Never guess in a race: three wrong numbers put you out.
Questions
Does every Sudoku have one solution?
Yes. Each puzzle is built by removing numbers from a full grid only while the puzzle keeps exactly one solution, so it can always be solved by logic.
What is the difference between the levels?
The number of given cells. 9x9 Easy starts with 40 numbers and Expert with only 22; 6x6 runs from 22 down to 14.
How does a Sudoku race work?
Everyone in the room gets the same puzzle and solves their own copy at the same time. You only see how far the others are, never their numbers. The first to finish wins.
Do I earn rewards for Sudoku?
Solo puzzles earn a little XP for signed-in players and your best times per size and level are saved on your device. Online races earn XP and Gems like other online games.
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