MasterSudokuQuest

A Master Sudoku Quest initially displays a partially filled grid. The aim of the game is to fill each square with a number from 1 - 9. Each number can only appear once in the same row, column or 3 x 3 box.

The classic Master Sudoku Quest game involves a grid of 81 squares. The grid is divided into nine blocks, each containing nine squares. The rules of the game are simple: each of the nine blocks has to contain all the numbers 1-9 within its squares. Each number can only appear once in a row, column or box.
A Master Sudoku Quest is defined as a logic-based, number-placement puzzle.
It is important to stress the fact that no number from 1 to 9 can be repeated in any row or column (although, they can be repeated along the diagonals).

it can have one (and only one) solution. There can be no ambiguity in Sudoku. Each number has a single location it must reside in. Otherwise, the player is forced to guess which location to choose thus changing the Quest into a game of chance.