Given

A given is a digit printed into a cell at puzzle start — a clue. The player can never erase or override a given; the rest of the grid has to be solved around them. The number of givens is roughly correlated with difficulty (fewer givens, harder puzzle), though the correlation isn't strict — clue placement and the deductive depth a puzzle requires matter more than the count alone.

A short note on the math

The minimum number of givens for a Sudoku with a unique solution is 17 — proven in 2012 by an exhaustive computer search. Most easy puzzles have between 35 and 40 givens; expert puzzles run 22 to 26. A puzzle with exactly 17 givens is publishable but rarely pleasant — the deductions tend to be technical and isolated rather than satisfying.

Why the term matters

"Given" is the term you'll see on technique-explanation pages and in puzzle metadata. When an article says "scan the givens first," it means look at the pre-filled digits — those are the constraints every empty cell is reasoning against. The givens alone don't usually determine the next move; the combination of givens and the deductions made so far does. As you place digits, your placed digits behave like givens for the cells you haven't reached yet — the constraint structure builds up cumulatively.

The givens in the row, column, and unit collectively constrain a cell's candidate set. For where to start scanning a fresh grid before any deductions are made, see Where to look first on a fresh grid. For the foundational rules a beginner should know, see How to play Sudoku.