Medium Sudoku Techniques
These six techniques take over when scanning and singles stop cracking the grid. Instead of placing a shape directly, each one removes candidates — and those removals are what open the next single. Pencil marks are your tool here; work through them in order.
- Naked PairsTwo cells in a unit sharing the same two candidates, so both shapes leave every other cell.
- Hidden PairsTwo shapes confined to the same two cells — clear the extra candidates those cells carry.
- Pointing PairsA shape trapped on one line inside a box, so it leaves that line everywhere outside the box.
- Box/Line ReductionA shape pinned into one box by a line, so it leaves the rest of that box.
- Naked TriplesThree cells sharing just three candidates between them, locking those shapes to the trio.
- Hidden TriplesThree shapes confined to the same three cells — strip away everything else they hold.
New to solving, or need the placing moves first? Start with the easy techniques, or see the full sudoku strategies hub.