Givens (also called clues) are the pre-filled digits that define a Sudoku puzzle. Their number and placement determine the puzzle's difficulty.
Givens are the digits already placed in the grid when you begin solving a Sudoku puzzle. They are set by the puzzle designer and cannot be modified during the solving process. Every valid Sudoku puzzle has exactly one solution, and the givens are carefully chosen to guarantee this uniqueness.
In most publications and apps, givens are displayed in a bolder font or different color to distinguish them from solver-placed digits. This visual distinction helps you avoid accidentally modifying a given during solving. To learn more about the rules governing givens and the grid, see our Sudoku rules guide.
The number of givens in a puzzle is one of the primary factors affecting its difficulty, though not the only one. Easy puzzles typically feature 30 to 35 givens, providing abundant starting information that allows solvers to make steady progress using basic techniques.
As puzzles get harder, the number of givens decreases and the techniques required become more advanced. Expert puzzles may have as few as 22 to 25 givens and require sophisticated strategies like X-Wing or forcing chains. However, difficulty also depends on which cells contain givens and which solving techniques are needed - a puzzle with 28 givens can sometimes be harder than one with 24.
In 2012, mathematicians proved that the minimum number of givens needed for a valid Sudoku puzzle with a unique solution is 17. No puzzle with 16 or fewer givens can have exactly one solution. This was a significant result in combinatorial mathematics and took years of computational effort to establish.
Puzzles with exactly 17 givens are extremely difficult and often require advanced solving techniques. They represent the absolute minimum information needed to define a unique puzzle. Learn more about this fascinating mathematical result in our article on minimum clues in Sudoku.
Explore more Sudoku terminology in the complete glossary.
Givens (also called clues) are the digits pre-filled in a Sudoku puzzle at the start. They are placed by the puzzle designer and cannot be changed by the solver. Givens provide the starting information from which all remaining digits must be logically deduced.
Most published Sudoku puzzles have between 22 and 35 givens. Easy puzzles tend to have more givens (around 30 to 35), while expert-level puzzles may have as few as 22 to 25. The minimum number of givens for a valid puzzle with a unique solution is 17.
Generally yes, but not always. The placement of givens matters as much as their quantity. A puzzle with 28 strategically placed givens could be harder than one with 25 givens that happen to quickly reveal key eliminations. However, as a broad trend, more givens correlate with easier puzzles.
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