Sudoku Solving Guide
Sudoku requires no guessing. Every puzzle can be solved through logical steps alone. This guide is organized from basic to advanced so you can progressively master each technique.
Beginner Techniques
Naked Single
More beginner techniques →A cell that can only take one possible number. The most basic technique — start here.
Hidden SingleWithin a row, column, or block, only one cell can hold a particular number. Takes practice to spot.
Intermediate Techniques
Naked Pair
When two cells share the same two candidates, those candidates can be eliminated from other cells in the row, column, or block.
Pointing PairWhen a number in a block is confined to one row or column, it can be eliminated from other blocks.
Box-Line ReductionWhen a number in a row or column is confined to one block, it can be eliminated from other rows/columns in that block.