Paused. The timer has stopped.
Hard puzzles are for players who enjoy Medium grids and want a proper challenge. You will need full notes and some patience, and you will be rewarded with the satisfying moment when a stuck grid suddenly opens up.
Which techniques you need
Hard puzzles on sudoku.ie may need everything from Easy and Medium, plus:
- Naked triples and hidden triples: three cells and three digits locked together.
- Naked quads and hidden quads: the same idea with four. These are rare.
- X-wing: one digit confined to the same two columns in two rows, or the same two rows in two columns.
Triples and the X-wing are the ones you will meet most often.
How long it takes
Most players finish a Hard puzzle in 20 to 45 minutes. Do not worry if your first few take longer.
When to play
The daily puzzle is Hard on Thursday and Friday.
A tip
On Hard puzzles, accurate notes matter more than anything. Before hunting for a triple or an X-wing, take a minute to check that every candidate is still valid. A single stale note can hide the move you are looking for. If you are still stuck, our guide to getting unstuck has a routine that works.