Intermediate

Naked Triple

Three cells in a unit whose candidates together use only three digits lock those digits out of the rest of the unit.

A naked triple is three cells in one unit whose combined candidates are drawn from only three digits. No single cell needs to show all three — the union across the three cells must total three digits. Those digits are confined to those three cells.

Common shapes are {1,2,3} / {1,2,3} / {1,2,3}, or partial sets like {1,2} / {2,3} / {1,3}.

How to spot it

Look for three cells in a unit whose candidates, pooled together, contain exactly three distinct digits. Those three digits must occupy those three cells, so remove them from every other cell of the unit.

  • Three cells, three digits total across them.
  • Each cell’s candidates are a subset of those three.
  • Eliminate the three digits everywhere else in the unit.
Three cells, three digits between them — a fourth cell drops to a single.

Worked example

  1. A row has three cells showing {1,4}, {4,7} and {1,7}.
  2. Their union is exactly {1,4,7} — three digits, three cells.
  3. The trio is locked, so 1, 4 and 7 leave the rest of the row.
  4. Another cell in the row drops to a single candidate.
  5. Place it and continue.

Try it yourself

9
6
2
5
1
3
6
4
8
7
9
5
4
3
6
3
5
7
8
5
3
8
7
9
1

Tap a cell, then a number, to practise.

Frequently asked questions

Must all three cells show three candidates?
No. Cells can show two or three candidates each; what matters is that their union is exactly three digits.
Is there a naked quad?
Yes — the same idea with four cells and four digits. It is rarer and harder to spot.

Related techniques

Practice: Naked Triple

Put the Naked Triple to work on a live board — free puzzles with notes, hints and four difficulty levels.

Try it on a live board

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