Sudoku Rocks is the ultimate Sudoku teaching site. Learning to play Sudoku is fun and easy. Many solving methods are explained, from the simple Only Candidate and Naked Twins to the difficult XY-Wings and Unique Rectangles.

Open Single Naked Single Hidden Single Only Candidate Unique Candidate in an Element Exclusive Element Naked Twins Naked Triplets and Quads Hidden Twins Triplets Quads X-Wings Swordfish Unique Rectangles XY Wings