Boxes are the 3×3 regions that make Sudoku unique among logic puzzles.
Understanding the Concept
A box (also called a block or region) is a 3×3 section of the Sudoku grid.
There are 9 boxes in total, arranged in a 3×3 pattern.
Each box contains 9 cells and must have all digits 1-9 when complete.
Boxes often have thicker borders to make them visually distinct.
The box constraint is what makes Sudoku different from similar puzzles.
Boxes are numbered 1-9, typically from left to right, top to bottom.
Examples
Box Positions
The 9 boxes are arranged like this: Top row (boxes 1-3), Middle row (boxes 4-6), Bottom row (boxes 7-9).
Pro Tips
- •Always check the box constraint when placing a number
- •Numbers in a box affect all cells in that box, regardless of row or column
- •Box intersections with rows and columns create powerful solving opportunities
