HELP FILE

Welcome to the Classic Sudoku Help File. Classic Sudoku is an addicting and challenging number puzzle game. Play just one game and you’ll be hooked! Click on any link on the left to jump to that page and learn more about the program.

Setting Up A New Puzzle Select “New Puzzle” from the main menu or at the top of the game board page. Set the options that you would like to play with from the resulting screen. Classic Sudoku lets you choose the level of difficulty, the method of error checking, timer setting, and the design theme.

Level of Difficulty: Choose from Easy, Medium, Hard or Impossible puzzles. Error Checking: The program defaults to displaying errors only when you ask. Classic Sudoku offers the ability to show incorrect entries as you type. This can be a great learning aid as you first begin tacking Sudoku puzzles. Timer Setting: You can have the timer running as you play, set it to display your time only after you’ve solved the puzzle, or not have a timer at all. Un-timed puzzles are not eligible for the Classic Sudoku Challenge (option that allows you to send your time and a code for a specific puzzle to challenge to a friend). Themes: Select from 5 different themes each time you play a new puzzle.

How To Play A Puzzle A Sudoku puzzle is 9x9 grid. The lines of squares running horizontally are rows, and the lines running vertically are columns. The grid is further divided into nine 3 X 3 squares called 'boxes'. Some of the squares already have numbers in them. Your task is to fill in the remaining squares. There's only one rule: Each row, column and box must end up containing all of the numbers from 1 to 9 with each number only appearing once in a row, column and box. For each Sudoku puzzle there is only one unique solution that can be arrived at using logic, not guesswork. The rules are simple, but the game is challenging. Each row, column and 3x3 box must contain the numbers 1-9 once, and only once. Sudoku is not a game that requires guessing. Each puzzle can be solved with logic (or process of elimination). For strategies on playing, select the “Strategies” button on the main menu. Once a puzzle is loaded on the game board, the timer is running. To enter your selection for any given square, click on the middle of the box and type in the number. Classic Sudoku also allows you to ‘pencil in’ notes on possible numbers for each box. To use this feature, click at the top of the square and you can enter up to 6 numbers in each square. These will be displayed smaller in the top quarter of the square in a light gray color. These numbers are ignored by the program, but allow you to keep track if your game and number placement. Any number – entry or note – can be deleted by highlighting it with your mouse and backspacing or typing over it.

Solving Strategies And Techniques Sudoku puzzles can be challenging and when you first try one, they may even seem impossible. Don’t worry. They really just require patience and understanding of a few strategies to help you solve them. One important facet of Sudoku cannot be over emphasized – these puzzles do not require any math. Sudoku is a logic challenge so no guesswork is required. How do you go about solving them? Most puzzles can be conquered using variations of these four techniques:

• Scanning • Triplets and Crosshatching • Penciling In • X-Wings

Scanning for Sole Candidates (or Singles)

Sometimes a square has only one possible number that can occupy it, once you consider the other squares in the same row, column and box. When a row, column or box uses eight different digits, it leaves only one available for the empty square. Example: In the partial puzzle below, the yellow square can only be a 2. See if you can see where the other digits are that make that true. (See illustrated explanation here).

Illustrated Explanation

Triplets and Crosshatching Because each set of three columns and three rows impacts the possibilities in each 3x3 box, you can use the concept of triplets to identify possible solutions. For example, if two columns in a set of three have the number 1 in them, you may be able to narrow down the placement of the third number 1. Look at the last set of three columns in the illustration below:

See why the circled square must contain a 1?

This technique can be extended to crosshatching, where you eliminate all rows and columns for a particular number to see what remains. If the number 3 had not been shown in the upper right corner of the same box, by

crosshatching rows and columns, you would still have been able to determine the placement for the number 1, as well as two additional number 1 placements.

The systematic approach of crosshatching first for the number 1, then the number 2, all the way through to 9 is the most effective. It is important to return to this technique as you fill in squares. It will allow you to discover even more answers as you revisit it.

Penciling In (Pencil marks) Another tool that helps to solve puzzles – “penciling in” – also uses the process of elimination. Once you have found all the “must be” numbers, you need to start working with “possible numbers”. To do this, you determine what numbers are still contenders for each square, and note them in the upper portion of the square in much smaller writing. You can then use logic to figure out what can be eliminated until you are down to only one possible solution per square. In this example, all of the possibilities have been identified and written as small numbers at the top of each empty square.

As you can see, some of them have only one contender.

If we look at the middle box on the right side, we see that one square can only be a 4 and another can only be a 9. Once we make a permanent notation of those, the square in the upper left corner can only be an 8. That means that the top middle square can only be a 6.

Now, let’s take a look at a more challenge box. The bottom middle box illustrates some great methods for solving Sudoku.

Because the two squares in the bottom row can both only be a 2 or a 5, no other square in this box can be a 2 or a 5. Therefore the middle square must be a 1 and the top left square must be a 3 and the top right square is 4 by default. To continue solving the puzzle, you analyze each box, row and column in the same manner, returning to crosshatching when you need to. Most Sudoku puzzles can be solved using these techniques. Sinister puzzles may require advanced procedures. Many of the more advanced techniques do not actually provide you with the exact placement of numerals, but instead guide you to cross out previously placed penciled-in numbers.

X-Wing X-Wings can be more difficult to understand than other solving techniques, but they offer real power when taking on difficult puzzles. An X-Wing is present when there are two lines, each having the same two positions for a single number. The key to this technique is to determine what would happen if you chose just one position to solve. What would happen to the numbers penciled-in other positions? First you must pencil-in all possibilities for the puzzle and then seek out rectangles in the puzzle in which each of the four corners share a penciled-in number. To understand this technique, first study this puzzle:

For example, look at the two 5s in rows 4 and 9.

If you assume the upper left cell is a 5, then the upper right cell must be an 8.

Additionally under the same assumption that the upper left cell is a 5, the lower left cell must be a 3 which would in turn make the lower right cell a 5.

In this scenario, a 5 in the upper left, forces the bottom right cell to also be a 5.

Using the same logic, had you started with the upper right cell, it would have forced the bottom left cell to be a 5. The forced lines form the X of this technique’s name.

Although this technique does not tell you which square on the right or left has the 5 in it, it does provide valuable information. We know that the 5 will definitely be in one of the two squares in each column, and we also know that a 5 cannot be anywhere else in either column or row. This allows us to remove other 5 candidates from those columns rows. In doing so, we determine that the top square in the third column must be a 7. This tells us that square in the third row of column one is a 3 and the middle

square must be 5. In this one example, you can see how this technique can get you unstuck and solving again!

Saving And Printing A Puzzle Saving A Puzzle You can save a puzzle in progress with all of your current entries by selecting “Save Puzzle” at the top of the game board. On the resulting page, enter a name for your puzzle and select the button next to the slot where you would like it saved. If you select a slot with a puzzle already stored in it, the new puzzle will replace the previously saved puzzle. To later retrieve a puzzle you have previously saved, select “Open Saved Puzzle” from the main menu or “Open Saved” at the top of the game board. From the list, choose the puzzle you wish to play. Printing A Puzzle If you want to print your puzzle and take it with you, select “Print Puzzle” at the top of the game board. Your computer’s print function box will appear. The program will print the puzzle in its current state, including any answers and/or notes you have entered.

Game Options Sending /Accepting A Challenge Once you have successfully solved a time puzzle, you will be presented with a challenge code. You can copy and paste that code into an email to share with another Classic Sudoku player. To accept a Challenge, select “Accept A Challenge” from the main menu. Copy the code shared by your fellow Classic Sudoku player, and paste it into the “Enter the Challenge Code” box. Clicking on the “Start Challenge” button will open the same puzzle with your competitor’s time displayed above your puzzle timer. Try to beat it! Undo Selecting “Undo” will undo the last action you performed. If you entered an answer, it will erase it. If you entered a note, the note will disappear. The game has one level of undo. Hints Classic Sudoku provides two helpful hints if you get stuck.

Flash Me – Selecting this option will flash the completed puzzle on the screen for a split second. When it flashes off, your puzzle will return to the screen. Show Errors – Selecting this option will turn any incorrect entered numbers from blue to red. As you replace these, newly entered numbers will be in blue again. If you would like to change all the numbers back to blue, you can select ‘Flash Me’.

Reset Puzzle Selecting “Reset Puzzle” will erase all of your current answers and notes, reset the timer and let you start the same puzzle over. There is an intermediate screen that asks you to confirm that you want to proceed with the reset. I Give Up You can select “I Give Up” when you want to stop playing the puzzle and see the answers. Main The “Main” button at the bottom of the game board takes you to the Main Menu of the program. From there, you can start a new puzzle, open a saved puzzle, accept a challenge, read strategies and more. Exit The “Exit” button at the bottom of the game board quits Classic Sudoku completely.

SUPPORT INFORMATION System Requirements Windows 2000 / ME / XP / Vista Pentium 233MHz or faster 256MB RAM or higher 70MB free hard drive space DirectX compatible video and sound cards CD-ROM / Mouse / Keyboard / Printer (optional) Installing Classic Sudoku on your PC 1. Insert the Classic Sudoku CD into your CD-ROM drive 2. If your computer is configured to detect a newly inserted CD, the Autorun menu will appear. If the Autorun menu does not appear after a few moments, click on the Start button, then select Run, and type D:\setup.exe (where D is the letter of your CD-ROM drive). If you are not sure of your CD-ROM drive’s letter, double-click on the “My Computer” icon.

3. Click on the Install option, and follow the onscreen instructions for installation and setup.

4. Upon successful completion of the install, you can launch the program either from the Classic Sudoku icon on your desktop OR by going to Start/Programs/On Hand Software/Classic Sudoku

Customer Support The quickest way to find an answer to your question is to click on this link: http://www.onhandsoftware.com/Support2.html This will take you immediately to the On Hand Software support site where we have posted the most frequently asked questions (FAQ’s) and help files. There are also some patches to programs that you can download. In a minute or two you can often find the answer you are seeking. However if you don’t find an answer to your specific question there, we have also included a Support Form so that you can tell us which operating system and computer you are using, as well as including your question. This form provides us with a more complete picture of the technical specs (computer brand, operating system) that we need to analyze and respond to your question. You’ll find the form at the bottom of the support page. We hope that you will quickly and easily find the information that you need on the support site or by using the product form.

REPORTING BUGS If you find a bug in our software, it would be helpful if you reported the bug to us via email to info@onhandsoftware.com To report a bug, please email us with BUG REPORT in the subject line. Please include the following information in your email:

• What operating system you are using • The software name and version # from the CD (ie PC103-01) • The error message • A brief description of what you were doing when the error appeared (ie did it happen upon launching of the game, or on a specific game level)

• Your name and email address so we can contact you when the bug is fixed.

When reporting bugs, detailed emails are necessary so we have a written record of the information our programmers will need to fix the problem.