Common Mistakes and How to Avoid Them

Traps that beginners often fall into.

The most common mistake is filling in an unconfirmed cell with a guess. A well-made Sudoku puzzle can always be solved without guessing, so if a cell isn't confirmed by logic, look elsewhere first.

Failing to update candidates is another problem. If you don't clear out related cells' candidates after confirming a number, it leads to faulty reasoning down the line.

Focusing on just one unit can also make you miss the bigger picture. When you're stuck, widen your view to other boxes or lines, and use the mistake-check feature to catch rule violations.