Web Sudoku Deluxe is a logic computer game developed by Web Sudoku. It is based on the popular Japanese logic game Sudoku. It features a grid of 9 boxes down and 9 boxes across. This grid can also be divided into smaller grids of 3x3 boxes each. At the start of each game, some of the boxes are filled up with the numbers 1-9, and some of the boxes are left blank. The objective of the game is to fill out the grid with the numbers 1 through 9. However, the rule is that each number must appear only once for each line, and each column. It must also appear only once per smaller grid. There lies the difficulty of the game.
Web Sudoku Deluxe features other variations of the game like Squiggly and Sudoku-X. Sudoku-X has an additional rule that the number 1-9 must only appear once in the diagonal line of boxes that extends from the top leftmost box to the bottom rightmost box, and from the top rightmost box to the bottom leftmost box, forming an X. The Squiggly rearranges the smaller grids of 3x3 into squiggly grids of 9 boxes each. Web Sudoku Deluxe also features other sizes including 4x4 and 6x6 for the easier levels, and 12x12 and 16x16 for the more difficult levels. The first two still utilizes number 1-4 and 1-6, while the 12x12 and 16x16 utilizes letters A-L and A-P.