Sudoku is an addictive logic puzzle that comes in varying levels of difficulty. The goal is to fill in all the squares in the 9x9 grid with digits in the range 1 - 9 inclusive. The placement of some digits has already been provided. The catch is that no digit may be repeated for each column, row, and 3x3 block. There are 9 such 3x3 blocks on the grid.
We rate our puzzles according to the following scale: Easiest, Easy, Medium, Hard, Very Hard, and Grueling. For some categories there are multiple levels yielding a total of 14 levels of difficulty. Each level of difficulty requires a new technique not required by the preceding levels.
If you enter an incorrect digit, the color of the digit entered will become red. Correct entries become blue.
Note that these puzzles may be solved using logic alone - no guessing :).
Each day we provide 14 new puzzles - one for every level of difficulty. There are enough sudoku puzzles for over 500 years of daily challenge at each level.
For more information on Sudoku, including strategies for solving, see Wikipedia
Following is our rating system along with the most difficult technique required for that level.
Sole Candidate (cross hatching)
Sole Candidate (cross hatching) with block possibles