Naked Triples and Hidden Triples extend the pair concept to three cells and three digits. Like their pair counterparts, they are two views of the same underlying constraint. Both unlock significant progress on hard puzzles, but each requires a different scanning approach. Mastering the relationship is essential for moving past intermediate Sudoku.
A Naked Triple is three cells in a unit whose combined candidates form exactly three specific digits - for example three cells together showing only 1, 4, and 7 with no cell containing anything else. A Hidden Triple is three digits that appear only in the same three cells of a unit, even though those cells may also contain other candidates.
A Naked Triple does not require every cell to contain all three candidates. Cells like (1,4), (4,7), and (1,7) form a valid Naked Triple even though no single cell shows all three. The key is that the union of candidates is exactly three digits and no cell contains any other digit.
A Naked Triple eliminates its three candidates from all other cells in the shared unit. A Hidden Triple eliminates all other candidates from its three cells. Hidden Triples often turn into Naked Triples after the elimination, exposing the structure that was buried.
Hidden Triples are notoriously hard to find. The trick is to scan a unit for any three digits where each digit appears in only two or three cells of that unit, and the cells overlap to form exactly three positions. Many solvers skip Hidden Triples entirely - this is a major missed opportunity in hard puzzles.
Master Naked Pairs and Hidden Pairs first. Triples extend the same logic to one larger size, so the foundational thinking transfers directly. When learning, work from a candidate-marked puzzle and force yourself to scan systematically rather than waiting for the pattern to leap out.
No. The cells just need to share a union of exactly three candidates. Many Naked Triples have cells with only two of the three digits.
A Hidden Triple has its three cells loaded with extra candidates. A Naked Triple has the cells already restricted to just the three digits.
Both appear in hard and expert puzzles. Naked Triples are easier to spot, so solvers find them more often, but Hidden Triples are equally frequent in the underlying logic.
Yes - if you skip them, you will get stuck on puzzles where Hidden Triples are the next available step. They are a crucial part of the intermediate toolkit.
Look for any three digits in a unit that each appear in only two or three cells, and check whether they collectively occupy exactly three cells. It is methodical work.
Yes. Naked Quads and Hidden Quads use four cells and four digits. The logic is identical - patterns just become rarer and harder to spot.
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