All Sudoku Techniques
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Beginner (4)
Intermediate (4)
Advanced (27)
- Naked TripleWhen three cells in a unit share only three candidates.
- Hidden TripleWhen three numbers can only fit in the same three cells.
- Naked QuadWhen four cells in a unit share only four candidates.
- Hidden QuadWhen four numbers can only fit in the same four cells.
- X-WingWhen two lines lock a candidate into the same two crossings.
- Finned FishWhen an almost X-Wing has extra candidates in one box.
- SkyscraperWhen two lines share one base and leave two roof candidates.
- Two-String KiteWhen a row string and a column string meet through one box.
- Empty RectangleWhen a box pattern combines with an outside strong link.
- Remote PairWhen matching two-candidate cells form a forcing chain.
- W-WingWhen two matching pairs are connected by a strong link.
- Simple Color TrapWhen one candidate is trapped by two opposite colors.
- Simple Color WrapWhen one color contradicts itself inside a unit.
- Multi Color TrapWhen two separate color chains trap an outside candidate.
- Multi Color WrapWhen one color is contradicted by another color chain.
- Unique Rectangle Type 1When one corner must break a deadly rectangle.
- Unique Rectangle Type 2When two roof cells share the same extra candidate.
- Unique Rectangle Type 3When roof extras combine with a naked subset.
- Unique Rectangle Type 4When one base candidate is locked into the roof cells.
- Unique Rectangle Type 5When diagonal or three roof cells share one extra candidate.
- X-ChainWhen one digit travels through alternating strong and weak links.
- XY-ChainWhen two-candidate cells form a forcing chain.
- AICWhen strong and weak links form a general forcing chain.
- SwordfishWhen three lines lock a candidate into the same three crossings.
- XY-WingWhen one pivot and two wings remove a shared candidate.
- XYZ-WingWhen a three-candidate pivot works with two matching wings.
- JellyfishWhen four lines lock a candidate into the same four crossings.