How to play
Sudoku

Your first round

1. Choose a row, column or box with only a few empty cells and list its missing digits.
2. Select an empty cell and eliminate candidates already present in its crossing units.
3. Enter a digit with the number pad or keyboard when only one candidate remains. Use Notes when several remain.
4. Recheck the affected row, column and box after each placement. Use Undo or erase to revise an entry.

Worked example

Build your strategy

• Look for a digit that has only one possible position inside a box, even when that cell has several notes.
• Update your own notes after placing a number; stale candidates can hide a new single.
• Use Check to find contradictions, then trace the deduction that produced them instead of replacing numbers at random.

Common mistakes

• Turning Notes on and wondering why entering candidates does not complete a cell.
• Assuming that an entry is correct simply because it causes no immediate duplicate.

Try this next

Finish an Easy puzzle using only deductions you can describe. Try Daily Sudoku when you want a consistent Medium challenge.