The grid
Sudoku is played on a 9×9 grid: 9 rows and 9 columns, making 81 cells in total. The grid is further divided into nine 3×3 boxes (sometimes called "blocks" or "regions").
The three rules
- Row rule: Each of the 9 rows must contain the numbers 1 through 9, with no repeats.
- Column rule: Each of the 9 columns must contain the numbers 1 through 9, with no repeats.
- Box rule: Each of the nine 3×3 boxes must contain the numbers 1 through 9, with no repeats.
That's the entire rule set. A properly made puzzle — like every puzzle generated by Sudoku SB — always has exactly one solution that satisfies all three rules at once.
What counts as a "given"
The numbers already filled in when a puzzle starts are called givens. They can't be changed or removed — they're the starting clues the rest of the solution is built from.
Common misconceptions
"Diagonals must also contain 1–9." Not in standard Sudoku — only rows, columns and boxes are restricted. (A variant called "Diagonal Sudoku" adds that rule, but it's not the classic game.)
"You can repeat numbers across different boxes." You can — and must. The same number appears in multiple boxes across the grid; it just can't repeat within the same row, column, or single box.
"Bigger numbers are worth more." Numbers in Sudoku are just labels — 1 through 9 could be any nine distinct symbols. There's no arithmetic involved anywhere in solving a puzzle.
Chances and mistakes in Sudoku SB
Sudoku SB adds a friendly chances system on top of the classic rules: you get 3 chances (❤️❤️❤️) per puzzle. Placing a number that breaks the row/column/box rule counts as a mistake and costs one chance — the underlying Sudoku rules themselves never change, this is just there to keep the game engaging.
Put the rules into practice
Reading the rules is step one — solving a puzzle is where they click.
PLAY NOW