Sudoku Help

Sudoku - Help and Game Instructions

How to play Sudoku ?

Target is to fill up a grid of 9x9 fields - some of them are already occupied - with the numbers 1 to 9 according to the following rules:

The numbers 1 - 9 are only allowed to appear once in each of the

• nine rows
• nine columns
• and 3x3 subgrids.

A "Sudoku" has only one unique solution. The number of already filled places varies and ranges typically between 20 and 38 out of the 81 possibilities.

The "Sudoku Generator" provides you a random Sudoku puzzle with givens in the range from 22 up to 31 numbers. You can choose between four difficulty levels - "Very Easy", "Easy", "Moderate" or "Difficult".

The "Sudoku Solver" gives you the solution to any Sudoku puzzle you will enter via mouse or keyboard.

In general you can use either the keyboard or the mouse to play this Sudoku. Once you have generated a Sudoku, you click into an open square. A number grid will pop up and you can now

• either click with the left mouse button on the number you select for this square
• or use the right mouse button to "pencil in" possible numbers for this square.

If you prefer the keyboard, simply type the number you select for this square. You can navigate with the mouse or the arrow keys.
Using the keyboard does not currently allow to "pencil in" numbers.

Sudoku Generator:
Get Sudoku:	Loads a Sudoku puzzle width a difficulty level as selected in the "Level" field and starts the game. The "Stop watch" is started.
Pause / Continue:	"Pause" the game until you click "Continue". The "Stop watch" is halted.
Check my Solution:	Validates your entered numbers. If you solved the Sudoku puzzle correctly, the watch is stopped and if the time you needed to solve the puzzle is within the ten best for the selected level, you will enter the "Best list".
Level:
Very Easy:	Sudoku puzzle can be solved by scanning for "Naked Singles".
Easy:	Sudoku puzzle can be solved by scanning for "Naked Singles and "Hidden Singles".
Moderate:	More than 25% but not all of the missing numbers can be found by scanning for "Naked Singles" and "Hidden Singles".
Difficult:	Less then 25% of the missing numbers can be found by scanning for "Naked Singles" and "Hidden Singles".
Help:
Show Solution:	Shows the solution for the Sudoku puzzle. Ends the game and the stopwatch is reset to "zero".
Spy Mode:	If selected and if you move the cursor over a square to be solved, a small infobox will open and will show you the allowed numbers for this square. You will not get to the best list once you have selected the "Spy Mode" for a game.
Number Grid Off:	If selected and if you click on a square to be solved, the number grid will not appear. The cursor within the square blinks and waits for input via the keyboard. This feature might be useful for players, who prefer using the numeric keypad.
Load Sudoku by Id:	Function only available for registered users
Id:	Enter the "Id" of the Sudoku puzzle to be loaded.
Load:	Loads the Sudoku puzzle width the "Id" entered in the "Id" field and starts the game. The "Stop watch" is started. That feature maybe useful, if you want to replay a game or if you want to challenge the solution time for a specific puzzle as listed in the "Best list".
Sudoku Solver:
Clear Field:	Clears the field and is necessary before you enter a Sudoku puzzle via keyboard or mouse.
Set Sudoku:	You "fix" the puzzle - and the squares with the given numbers will be shaded in grey color.
Solve Sudoku:	The solver will display the solution of your Sudoku puzzle. In case there is no solution or if the entered puzzle is not a regular Sudoku, a message will pop up.
	Save the current generated Sudoku as "pdf" for printout. The pdf document includes the puzzle and the solution as well.
	This page
	This page will provide you overall and for registered users individual game statistics like the median solution time for the different levels a chart and a table providing relevant information for all the Sudokus you played;