Sudoku is played on a grid of 9 x 9 spaces. Within the rows and columns are 9 \u201csquares\u201d (made up of 3 x 3 spaces). Each row, column and square (9 spaces each) needs to be filled out with the numbers 1-9, without repeating any numbers within the row, column or square. LofGames made a very easy user interface and many more feature for you to enjoy the classical SUDOKU game.