Knowledge

Sudoku Glossary: Quick Reference for Common Terms

2025-01-21 · 3 min read

This page compiles common Sudoku solving terms for quick reference while learning techniques.

Basic Terms

Cell
A single square on the Sudoku grid. Each cell must contain exactly one digit.
Box
A 3×3 region in standard Sudoku. Each box must contain digits 1-9 exactly once. A 9×9 Sudoku has 9 boxes.
Candidate
A possible digit for a cell. When only one candidate remains, the cell is solved.
Bi-value Cell
A cell with exactly two candidates remaining.

Chain-Related Terms

Chain
A series of links between candidates. The relationship between chain endpoints allows certain eliminations. All loops are closed chains.
Strong Link
A relationship between two candidates: if one is false, the other must be true. Can exist in bi-location cells, bi-value cells, or more complex structures.
Weak Link
A relationship between a candidate and other candidates in the same unit: if that candidate is true, all others must be false.

Locked Set Terms

Locked Set
N candidates confined to N cells. All same candidates that can see the locked set can be eliminated. Pairs, triples, etc. are locked sets.
Note:
This glossary will be continuously updated. For more detailed explanations, refer to the specific technique articles.