Peak Sudoku

Naked Triple

Three cells in a house whose candidates are drawn from the same three digits.
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Overview

Tier 3
Subsets
Typical difficulty
Peak Score 40–55
Also known as
Disjoint Triple, Naked Triplet

When three cells in a house share candidate options drawn exclusively from a set of three digits {A, B, C}, those three digits must occupy those three cells, clearing them from the rest of the house.

A Naked Triple expands the logic of a Naked Pair to three cells and three digits. A crucial detail that trips up many solvers is that not all three cells need to contain all three digits. The cells can contain any subset of the three digits (such as {A, B}, {B, C}, and {A, C}), as long as their collective candidate pool contains no other numbers besides A, B, and C.

Worked examples

1 / 5
Reading the exampleCells forming the patternCells losing candidatesEliminated candidates
In column 8, R1C8, R2C8 and R3C8 hold only {1,6,9} between them. Those three cells must take those three digits, so 1, 6 and 9 can be removed from the rest of column 8.
Removes: 9 from R5C8, R6C8, R7C8 · 6 from R5C8, R7C8 · 1 from R7C8

How to apply it

Spotting the pattern and making the deduction, in order.

  1. Scan a row, column, or box for three cells whose candidates are restricted to three shared digits (e.g. 2, 5, and 8).
  2. Check that no fourth candidate number appears in any of those three cells (cells can hold pairs like {2, 5} or all three {2, 5, 8}).
  3. Because three numbers must fit into exactly three cells, those digits are completely locked into that group.
  4. No other cell in that row, column, or box can ever hold any of those three digits.
  5. Erase all three candidate numbers from every other cell in that shared unit.

Common mistakes

  • Believing that every cell must hold all three digits. A triple of {1, 2}, {2, 3}, {1, 3} is a 100% valid Naked Triple.
  • Accidentally including a fourth digit (e.g. {1, 2}, {2, 3}, {1, 3, 4} is NOT a triple).
  • Forgetting to eliminate all three digits from the rest of the house.

Frequently asked questions

What are the common patterns for Naked Triples?
The classic shapes are: full {ABC, ABC, ABC}, two-candidate wings {AB, BC, AC}, and mixed sets like {AB, BC, ABC} or {AB, AC, ABC}.
Is a Naked Triple harder to spot than a Hidden Triple?
Generally no. Naked Triples are easier because you look at the pencil marks inside the cells. Hidden Triples require looking at the digits across the entire house.
Can a Naked Triple span across two boxes?
Yes, as long as all three cells lie in the same row or column. If they all sit within the same box, you can eliminate candidates from the box too.
Peak Score 30–45Naked PairTwo cells in the same house contain exactly the same two candidates.Peak Score 50–65Naked QuadFour cells in a house sharing four candidates between them.Peak Score 45–60Hidden TripleThree digits confined to the same three cells of a house, clearing all other candidates from those cells.

Put Naked Triple into practice

Try a puzzle from the Tricky tier (Peak Score 41–50).

Play a Tricky puzzleAll 25 techniques