SUDOKU - Fun puzzle game! Play more games on the left-bar menu INTRODUCING: The object of the game is to fill the Sudoku grid with a sequence of single-digit numbers, each of which appears only once in a given row, column, or 3×3 block. At the start, there are a number of pre-populated cells in the grid that act as clues to help the player gradually solve the whole puzzle. By definition, a valid grid must have one (and only one) solution. We make sure that all our grids have a unique solution. While it is easier to design a grid with multiple solutions (or no solutions at all), that cannot be considered a real puzzle. As in the case of many logic games, there can be only one answer. Therefore, great care should be taken when designing as even a misplaced number will render the puzzle unsolvable. CHECK IF THE NUMBER APPEARS OR NOT If a number appears, determine which other squares in the same row or column cannot accept the number; If the number does not appear, determine which other squares cannot accept the number, with a different occurrence of the same number in other blocks in the same row and column. When there’s only one possible value for a row, column, or block, this is where the numbers come in. With a little experience, you should be able to visualize the squares where the number might appear as if the number were “lit” on the grid. This will allow you to detect more advanced configurations.