Learn sudoku with Deuce
Never solved one? Deuce will walk you through it, one cell at a time. Already a solver? Skip to the variant you're stuck on.
Three rules. That's the whole game.
A sudoku is a grid split into rows, columns and boxes. Some cells start filled in. You fill the rest so that no digit ever repeats where it shouldn't.
holds 1 to 9, each once.
holds 1 to 9, each once.
holds 1 to 9, each once.
No maths, no guessing. Every digit you place is one you can prove. If you're guessing, there's a clue you haven't spotted yet.
Solve a Mini 6x6 with Deuce
A Mini is the same game on a smaller board: digits 1 to 6, and boxes two rows tall and three columns wide. Press Next and Deuce places one digit at a time and tells you why.
Amber is the cell Deuce is filling. Shaded cells are the ones he's looking at.
Classic
The original 9x9. The other variants all build on it.
How it plays
Fill the 9x9 grid so every row, column and 3x3 box holds 1 to 9 once. Easy puzzles give you lots of starting digits. Expert puzzles give you very few.
Where to start
Pick a digit that's already on the board a lot. Go box by box and ask where that digit can go. Rows and columns that already have it rule cells out.
Finish a Classic with Deuce
Amber is the cell Deuce is filling. Shaded cells are the ones he's looking at.
X-Sudoku
Classic, plus the two long diagonals.
What's different
Both corner-to-corner diagonals must also hold 1 to 9 once each. That's two extra groups to check, and two extra ways to find a digit.
How to play it
Use every Classic trick, then scan the diagonals the same way you scan a row. The centre cell sits on both diagonals, so it has to fit five groups at once.
Finish an X-Sudoku with Deuce
Amber is the cell Deuce is filling. Shaded cells are the ones he's looking at.
Diagonals are free clues. Check them first. Most people forget they're there.
Killer
No starting digits at all. Just cages and sums.
What's different
The board starts empty. Dashed outlines, called cages, group cells together, and the small number in the corner is what those cells add up to. Digits can't repeat inside a cage. Rows, columns and boxes still need 1 to 9 once each.
How to play it
Start with cages that can only be made one way. Pencil those digits in, then let the normal rules do the rest. Each cage is tinted so you can tell neighbours apart.
Finish a Killer with Deuce
Amber is the cell Deuce is filling. Shaded cells are the ones he's looking at.
Cages with only one answer
3 in two cells can only be 1 and 2.
17 in two cells can only be 8 and 9.
6 in three cells can only be 1, 2 and 3.
4 in two cells is 1 and 3. Never 2 and 2.
Every row, column and box adds up to 45. When all but one cell of a box is covered by cages you know, that last cell is 45 minus the rest. Looks smart. Is smart.
Flurry (Sudoku Mine)
No digits at all. Find the hidden snowflakes. Based on Sudoku Mine.
What's different
You don't place numbers. You find 27 snowflakes, exactly 3 in every row, column and 3x3 box. A number tells you how many of the 8 cells around it hold a snowflake. Numbered cells never hold one.
How to play it
Mark the cells you know are safe with a dot and the ones you know hide a snowflake with a flake. Look for numbers whose open cells must all be snowflakes, and rows or boxes that already have their 3.
Solve a Flurry with Deuce
Amber is the cell Deuce is filling. Shaded cells are the ones he's looking at.
Dots are free. Mark every cell you know is safe and the snowflakes start to show themselves.
Samurai
Five Classic grids, joined at the corners.
What's different
Four grids sit at the corners and one in the middle. The middle grid shares one 3x3 box with each corner grid. Every grid follows the Classic rules, so the shared boxes have to work for both grids at once.
How to play it
Start in the shaded shared boxes. They get help from two grids, so they fill first.
Solve a Samurai with Deuce
Amber is the cell Deuce is filling. Shaded cells are the ones he's looking at. Tinted boxes belong to two grids.
It's big, but it's never harder than its hardest grid. Finish one grid, then use its corner box to break into the next.
How Deuce uses pencil marks
What they are
Small notes in a cell listing the digits it could still be. They don't count as answers, so they never cost you time or mistakes.
How to use them
Write marks small in the corner of a cell, on paper or in your app's pencil mode. Each time you place a digit, cross it off the marks in the same row, column and box.
Amber is the cell Deuce is filling. Shaded cells are the ones he's looking at.
Four habits that solve most puzzles
Pencil marks
Jot the digits a cell could still be, one box or row at a time. When a cell is down to one mark, place it. Watch Deuce do it.
Only one digit fits here
Look at one empty cell. Cross off every digit already in its row, column and box. If one digit is left, that's the answer.
Only one place for this digit
Look at one box, row or column and one digit it's missing. If every other spot is blocked, the digit goes in the last one.
Pairs
Two cells in a row that can only be the same two digits, say 4 and 8, use up the 4 and the 8. Cross those digits off everywhere else in that row.
Ready to race? Try Deducely.
Six daily puzzles, the same for everyone, every day. No ads, ever.
Classic, X-Sudoku, Killer, Mini 6x6, Flurry and Samurai. Difficulty climbs through the week.
Play it again as much as you like. Only your first finish ranks.
Each wrong digit adds 5 seconds to your ranked time. Undoing it doesn't take the time back.
Faster finishes earn more points. Your last 30 days decide your rank.
