The object of sudoku is to fill in the cells of the game board with the numbers 1 thru 9 so that each row, each column and
each 3x3 grid contains all nine numbers without any dublicate numbers. Some cells will be prefilled so that each game will
have one, and only one, solution.
Select Options
- Difficulty dropdown:
- Select the difficulty level of the game when clicking the Play Random or Selected Game buttons.
- Game text box:
- Enter the number of the game to play or edit.
- Play Random Game button:
- Click to play a random game at the specified difficulty level.
- Play Selected Game button:
- Click to play the game with the specified number or closest one at the specified difficulty level.
- Edit Selected Game button:
- Click to edit the specified game.
- Create New Game button:
- Click to create a new game.
Play Options
- Elapsed Time display:
- Shows the amount of time (formatted as MM:SS or HH:MM:SS) that you have been playing the game.
- Mode radio buttons:
- Select the mode that numbers are written to the game board. Pen - a single value is written to each cell and used to valid puzzle solution. Pencil - multiple values can be written to each cell.
- Bookmark dropdown:
- Select the state of the game to be restored.
- Save New button:
- Click to save the current state of the game as a new bookmark.
- Restore button:
- Click to restore the game to the state the game was in when last saved. Note: Bookmark 0 is the game saved at the start.
- Play Random Game button:
- Click to play another random game at the specified difficulty level.
- Play Next Game button:
- Click to play the next game after the specified game limited by the selected difficulty level, if any.
- Select Game button:
- Click to return to the Select Options page.
How to Play a Game
Each new game starts in Pen mode. Mouse over an available cell on the game board to select it.
The cell background will turn light blue.
Press a number to enter a value or press the space bar to clear the cell.
Click on the cell to bring up a keypad that can be used to enter a number or to clear the cell.
Note: the keypad also has the option to show the solution for the cell as a hint in solving the puzzle.
When there are duplicate numbers in a row, column or grid, the duplicates are displayed in red.
Select the Pencil mode when you want to enter one or more possible solutions in a cell. When selected, the cell background
will turn gray. When a number is already pencilled in, entering the number again will clear just that number from the cell.
For some games, logic alone is not always enough to solve a puzzle. Sometimes trial and error is needed. In these cases,
a bookmark can be saved. If the trail solution does not work, the puzzle can be restored to the bookmarked state and
a new solution can be tried.
Edit Options
- Test Game button:
- Click to validate the puzzle and to display the solution.
- Add Game button:
- Click to validate and add the new game.
- Update Game button:
- Click to validate and update the existing game.
- Play This Game button:
- Click to play the the game.
- Edit Next Game button:
- Click to edit the next game.
- Create New Game button:
- Click to create a new game.
- Select Game button:
- Click to return to the Select Options page.
How to Edit a Game
Mouse over a cell on the game board to select it. The cell background will turn blue.
Press a number to enter a value or press the space bar to clear the cell.
Click on the cell to bring up a keypad that can be used to enter a number or to clear the cell.
Once the Prefilled cells have been entered, click on the appropriate Add or Update button.
The validation routine will attempt to solve the puzzle.
If one, and only one, solution can not be found, the partial puzzle solution will be displayed with an appropriate error message.
Otherwise, the puzzle will be added or updated as appropriate.