Puzzle #133, level 2

Setup Mode     Manual Mode     Flag Lone Numbers
            

Load a random Game Level: 1 2 2+ 3 3+ 4 4+ 5 5+ 6

Setup your own Game Load a Blank Grid

Load a saved Game

Instuctions
The small green numbers in a cell indicate which numbers are possible in a cell. Click on a green number to tell that this number cannot be in this cell. Click on the last remaining green number to have this number appear in the cell.

Manual Mode
When "Manual Mode" is checked, none of the green numbers are removed automatically. You have to click on them manually. When "Manual Mode" is unchecked, the system removes all the corresponding green numbers in a row, column, and box, when a big number comes up in a cell.

Flag Lone Numbers
When "Flag Lone Numbers" is checked, the system checks if a small number is the only one of its kind in a row, column, or box, and flags them in red. A red small number in a cell means this is the big number that should be in this cell. Click on a red number (even with remaining green numbers) to bring a big number in the cell. This is the "Easy Mode" to solve the problem real quick. Check this box, and click on the succession of red numbers.

Auto Solve
Click on the "Auto Solve" button to let the system fill the big numbers for you automatically. This will solve 99% of the puzzles. Note that there are some rare puzzles that are still solvable and that "Auto Solve" does not solve completely. See puzzle #45 for instance. Load this game and click on "Auto Solve". Not all the numbers are filled. Check the top-right box. The number 6 has to be in the top-right or middle-right, therefore on the right column in any case. This means the middle-right cell of the middle-right box cannot be a 6. This means this cell can only contain a 7. Bring the 7 in this cell, and click "Auto Solve" again to bring all the other numbers.
If a cell is left blank after you click on the "Auto Solve" button it means that the grid as it was filled, was unsolvable, i.e. you had some of the wrong numbers in the cells.

Refresh
The "Refresh" button is used to recalculate the possibilities in the grid if you make a mistake. For instance, if you bring the wrong number in a cell, you can click on it again to remove it and bring back the green numbers on this cell, but some of the green numbers in the row, column, and box would have been removed (when "Manual Mode" is unchecked). Click on "Refresh" to set the green numbers back to the correct visible/invisible position.

Restart
The "Restart" button is used to reload the grid the way it was when the puzzle started. This button is only displayed when a grid was loaded from a saved puzzle, or from a random game request. So if you hit a dead end while trying to solve a puzzle you can hit this button to try again.

Setup Mode
When "Setup Mode" is checked, clicking on a green number will bring the big number in the cell even when there is more than one green number visible. This is useful to setup a new game. Bring a blank grid on the screen by clicking on the "Load a Blank Grid" link, then click on all the original numbers in the puzzle you are trying to setup. Then uncheck "Setup Mode" and start working on the puzzle.

Save
You can save a puzzle at any time. This will bring a screen with a unique id number in it. Write down this number to reload the saved puzzle later. Use the "Load a Saved Game" form in the bottom right to reload the saved puzzle.

Load a Random Game
Click on the "Load Random" buttom to load a random game. Specify a level of difficulty on the left of the button to load a random game of a given difficulty. Select a level with a "+" after the number to load a random game of this difficulty or above.

Glossary
Box: one of the 9 big squares with 9 sudoku numbers.
Cell: one of the 9 cells in a box.
Green Numbers: the 9 small numbers in each cell used to help you solve the puzzle.
Big Numbers: the big black numbers that are part of the sudoku puzzle.