Welcome to Sudo-San!

"Good morning, my pupil. I have decided you are ready for your next challenge. Be aware that many have failed before you. But if you succeed, you will learn... the secret of the mighty Sudoku."



Sudo-San is an accessible version of the popular puzzle game Sudoku. Sudoku is a logic-based placement puzzle which aim it is to enter a numerical digit from 1 through 9 in each cel of a 9x9 grid starting with various digits in various cells. Each row, column, and region must contain only one instance of each numeral. Completing the puzzle requires patience and logical ability. Sudoku attained a huge international popularity in 2005 and has already been called the "Rubik's cube of the 21st century".

Sudo-San is the first online accessible Sudoku that features a graphical interface and an extensive auditory interface, enabling blind players as well as sighted players to play Sudoku.

Screenshot of Sudo-San, showing a partially filled-in sudoku puzzle. It features the words Sudo-San on top and the puzzle seems drawn on a canvas-like background which is decorated with chinese flowers. Below the puzzle is a white bar with pictures and text that explain the keycommands that are used in the game.


Here's all the information on how to play Sudo-San. Please read it carefully to avoid problems:

Step 1 : Installation
To play Sudo-San you need to have the Macromedia Shockwave plugin installed. Click here to download the plugin if you do not have it installed already.

Step 2 : Rules of Sudoku
Sudoku is a puzzle that is very simple to understand but often quite hard to master. A Sudoku-puzzle consists of a 9×9 grid, made up of 3×3 sub-grids (named "squares" hereafter). Some cells already contain numbers while others are empty. Your goal is to fill in the empty cells following these three simple rules:

  • Every column must contain the numbers 1 through 9
  • Every row must contain the numbers 1 through 9
  • Every 3x3 square must contain the numbers 1 through 9

So this means that each column, row, and square contains the numbers 1 through 9 exactly once!

Completing a Sudoku puzzle is a process of elimination, you need to find a square where only one number can go in it. For example, if column 1 features a number "3" in the left-top square and column 2 features a number "3" in the left-bottom square, this means that the left-middle square must feature a number "3" somewhere in the 3rd column. Likewise, if row 7 features number "5" in the right-bottom square and row 8 features number "5" in the middle-bottom square, then the left-bottom square must feature number "5" somewhere in row 9. And if a square features numbers "1" to "7" it means that the two empty cells in this square must contain an "8" and a "9". For a complete guide with strategy tips we recommend the Sudoku-page at Wikipedia.org. We also recommend starting with simple puzzles to get the basics of the game.

Sudo-San is completely accessible for blind players and features an extensive auditory interface next to a graphical interface. Your guide and mentor is Grandmaster San (or Sudo-San). His voice will help you around the puzzle. When the game is loaded, a new puzzle is automatically generated and the cursor (or focus) is on the left-top cel (row 1, column 1).

You scan the puzzle using the cursor keys to move from cel to cel. Every move will be accompanied by a soft sound. To hear your current location, press the "O"-key (for 'orientation'). When you encounter a cel that contains a number, Sudo-San will tell you.

If you want to enter a number in an empty cell, first press the Enter-key and then a Number-key of your choice. The number is then entered in the cel unless there is a conflict. A conflict arises whenever you try to enter a number and that number already exists in that row, column or square. Sudo-San will tell you what the conflict is and the number is not added to the cel. You can not add a number to a cel which already contains a number. To delete a number, press the Enter-key and then the Delete-key. The number is then deleted. Please note that you can *only* delete numbers that you entered yourself and not the numbers that were originally entered by the computer.

Sudo-San can assist you by telling you the contents of a row, column or square in one go. So to hear the contents of a row, press the "R"-key (for 'row). Sudo-San will then read the complete row from left to right. To hear the contents of a column, press the "C"-key (for 'column'). Sudo-San will then read the complete column from top to bottom. To hear the contents of a square, press the "S"-key (for 'square'). Sudo-San will then read the complete square from left to right, top to bottom.

When solving a Sudoku puzzle, many find it useful to mark candidate numbers (or "candidates") in empty cells. For example: a row contains 7 numbers while two cells are empty. After scanning the row you find that you only need to enter a "2" and a "9" in this row. Now you know that each of the two cells could either be a "2" and a "9". So to help you remember you mark the empty cells. You mark an empty cel simply pressing a Number-key. This will toggle the appropiate candidate number. Cells can be marked with multiple numbers from 1 to 9. So for example, you press the "9"-key in an empty cel, that cell is now marked with a "9". To mark the same cel with a "2", press the "2"-key. To delete a mark, simply press the number again. To hear the candidates that you marked in a cel, press the "X"-key. Sudo-San will now tell you how you marked the cel. Whenever you enter a number (using the Enter-key and then a Number-key), every candidate number that you marked in the cel will be removed, as well as any candidates of the same number in the row, column and square. For example: you have marked a cell with a "2" and a "9". You find that the cel must feature a "9". You press the Enter-key and then the "9"-key. The marks in the cel will be removed and a "9" is entered in the cel. Every "9"-marks in the row, column and square are removed too.
An alternative technique that some find easier is to mark up those numbers that a cell cannot be. Thus a cell will start empty and as more constraints become known it will slowly fill. When only one marking is missing, that has to be the value of the cell.
Please note that you do not *have* to mark a cel. But marking candidates will often help you to solve the Sudoku, especially with harder puzzles.

The game features adaptive background sound and music. It will change gradually while you are filling the puzzle with numbers, informing you of your progress. When you want to turn the music off, press the "M"-key (for 'music'). When you want to turn the music back on, press the "M"-key again. It is also possible to turn off the voice of Sudo-San by pressing the "V"-key (for 'voice'). This is not recommended for blind players because most of the accessible interface revolves around the voice of Sudo-San. The option to turn of the voice is originally intended for sighted gamers only. If you accidentily turn of Sudo-San's voice, you can turn it on by pressing the "V"-key again. You can also toggle the sound effects by pressing the "E"-key.

When you have solved a Sudoku (or when you want to start a new one) press the "N"-key (for 'new') to generate a new puzzle. Sudo-San will tell you that a new puzzle has been created. Pressing the "D"-key (for 'difficulty') lets you navigate through three difficulty settings: "Easy", "Normal" and "Hard". The default puzzle is set to "Easy".

You now know everything to play the game. At the bottom of this page is a summary of all the key-commands. Unfortunately it is not yet possible to define your own key-set for the game. This option might be added to a future version of Sudo-San. Should you have any comments or questions related to Sudo-San, don't hesitate to ask them on the AudioGames.net forum, where we set up a special forum fo Sodu-San. Click here to visit the Sudo-San forum.

Step 3: Play
Now you're ready to play Sudo-San! The link below will take you to the game which will start automatically.

Click here to play Sudo-San!

Sudo-San has been played $counter times...

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Here's a summary of all the key-commands:

  • "Cursor Keys": move cursor/focus around the puzzle
  • "Enter" followed by "1"..."9": enter number in empty cel
  • "Enter" followed by "Delete": delete number in cel
  • "1"..."9": toggle candidate number in cel
  • "R": hear row from left to right
  • "C": hear column from top to bottom
  • "S": hear square from left to right, from top to bottom
  • "X": hear candidates marked in cel
  • "O": hear current location / orientation
  • "M": toggle music
  • "V": toggle Sudo-San voice
  • "E": toggle sound effects
  • "N": generate new puzzle
  • "D": set difficulty