What is a hidden triple?
A hidden triple occurs when three candidate digits are restricted to three cells within one unit.
Pure Sudoku
Intermediate technique
Hidden triples restrict three digits to three cells.
When three digits can appear only in three cells of a unit, those cells must contain the digits. Extra candidates inside the cells can be erased.
- Level
- Intermediate
- Pattern
- Three digits restricted to three cells
- Outcome
- Logical progress
Focused example
Digits 2, 5, and 9 are restricted to the three highlighted cells.
The highlighted cells show the exact scope of the pattern. Read the candidates before making an elimination.
How it works
Apply the pattern in four checks.
- Scan a unit and map the possible positions of each candidate digit.
- Find three digits whose positions are limited to the same three cells.
- Keep those three digits in the selected cells.
- Remove unrelated candidates from those cells; do not eliminate the triple elsewhere.
Know the difference
Use the pattern only when every condition is true.
Naked triples are identified by the candidates inside three cells. Hidden triples are identified by where three digits can appear across the whole unit.
After the move, re-scan the affected unit for singles before searching for another advanced pattern.
Continue playing
Choose your next Sudoku route.
FAQ
Quick answers before you play.
What candidates are removed?
Remove candidates other than the three hidden digits from the three selected cells.
Why are hidden triples difficult to see?
The useful digits are mixed with extra notes, so the restriction only appears when you compare candidate positions across the unit.
Practice loop
Find it on a live board.
Pause when the board slows down, check the candidate conditions, make one justified move, and scan again.