Impossible Sudoku Puzzles are not exactly impossible to solve, but they sure can feel as such. To reach and solve this level players must not believe to be experts, but rather be one. The logic required to solve them is extremely advanced, and high focusing and concentration skills are a requirement. Using the notes feature is also a necessity as the puzzle becomes impossible to solve without them.
Nevertheless, the rules and principles of Sudoku remain unchanged and, as with an easy level, all you have to do is fill the grid with numbers from 1 to 9 without repeating any digit in each column, row, and group. Only the allocated clues at the start of the game are reduced to a minimum at this level. You can also be certain that it is possible to solve them and there is only one solution available.
The incidence of applicable common strategies is considerably reduced in an impossible Sudoku level. Techniques used in easy to evil levels might not bear any fruit and result simply in the addition of more candidates to one single cell.
Chain based hypothesis/disproof techniques will be the only option to solve them and your analytical and logic skills must be highly advanced to apply these.
The same basic tips to solve any Sudoku puzzle remain the same, however. You must try to keep your momentum when finding the solution for a cell and check the immediately affected columns, rows or groups right away as new options might have unlocked in those. Remember to also keep your notes clean and updated to avoid cluttering the grid with unnecessary and distracting information.
Above all, to solve an impossible Sudoku puzzle you will need high doses of concentration and patience but remember that the solution is possible and is within your reach with the right mental tools. Don’t despair and give it your best!