Mirrored from Sudopedia, the Free Sudoku Reference Guide


A valid or proper Sudoku has a unique solution, otherwise it is an invalid Sudoku.

Opinions differ about the use of this qualifier. Some players state that the name Sudoku implies that there is a unique solution. A puzzle with multiple solutions only looks like a Sudoku.

This page was last modified 19:49, 8 November 2007.