Sudoku Rules

Easy

Normal

Hard

Expert

Master

Sudoku Techniques: Last Free Cell

Last Free Cell

Only one number remains – place it in the empty cell

Sudoku Techniques: Last Remaining Cell

Last Remaining Number

No other numbers are possible in the cell

Sudoku Techniques: Last Possible Cell

Last Possible Cell

The number can go in only one cell

Sudoku Techniques: Naked Single

Naked Single

Only one candidate left. Just fill it in!

Sudoku Techniques: Hidden Single

Hidden Single

Find a candidate that fits only one cell