In association with the leading Su Doku website, sudokufun.com, this program brings you a virtually limitless supply of high quality Su Doku puzzles. For the uninitiated, these puzzles require only logic to place numbers in a 9 x 9 grid. The only rule is that each row, column and 3x3 box must each contain the numbers 1 to 9 exactly once. True Su Doku puzzles, like the ones this game provides, only have one possible solution. This solution can be reached using pure logic; no guesswork is required at any step. When downloaded, three puzzles are provided for free. The first one is easy, the second is medium, and the third is difficult. When registered this game gives you 23 unique puzzles, and the ability to download more puzzles of varying difficulty. 50 puzzles can be stored at any one time. When playing the more difficult puzzles it may seem that you have to guess. However, logic can be used at every step. For solving advice please see www.sudokufun.com. Pencil marks (used to annotate the puzzles) can be overlayed on top of the puzzle in a transparent layer. Alternatively a different visual mode displays the pencil marks to the right of the puzzle. Please note that this edition will not run in conjunction with any other edition of SudokuFun. This edition is identical to the value edition in every way, except the value edition only allows you to store 20 puzzles at once.