Sudoku is a logic puzzle about where digits can go.
In classic Sudoku, you start with a 9×9 grid containing a set of fixed clues. Your job is to fill the remaining cells so that every row, every column, and every 3×3 box contains the digits 1–9 exactly once.
The numbers are labels, not calculations. You never need to add or multiply anything: solving comes from using the grid's restrictions to rule out impossible positions until the remaining placements are forced.
What is the goal of Sudoku?
The goal is to complete every empty cell while satisfying all three unit rules at the same time.
For a classic 9×9 Sudoku, a completed puzzle must satisfy three conditions:
- Every row contains the digits 1–9 exactly once.
- Every column contains the digits 1–9 exactly once.
- Every 3×3 box contains the digits 1–9 exactly once.
The digits already printed in the puzzle are called givens or clues. They cannot be changed. The remaining cells are solved by using those givens, the digits you place, and the restrictions created by the rows, columns, and boxes.
Is Sudoku a math puzzle?
Sudoku uses digits, but solving a standard Sudoku is mainly about logic and pattern recognition rather than arithmetic.
If a row already contains 1, 2, 3, 4, 5, 6, 7, and 9, you do not need a calculation to find the missing digit. You simply know that 8 is the only digit from 1–9 that is not present.
More difficult puzzles use the same underlying rules. The challenge comes from combining restrictions and recognizing patterns, not from doing harder mathematics.
How does a Sudoku puzzle begin?
A Sudoku starts with some cells already filled. These givens create the initial structure of the puzzle.
A well-formed puzzle is designed so that the remaining cells can be completed consistently. In the kind of classic Sudoku VeyraPlay intends to publish, the puzzle should have a single solution.
You usually begin by looking for places where the existing givens leave very few possibilities. As the grid fills, each new solved cell creates additional restrictions, which can reveal the next move.
What makes Sudoku a logic puzzle?
Every placed digit affects three parts of the grid at once:
- its row
- its column
- its box
Suppose you are considering whether a cell could contain 5. If there is already a 5 in that cell's row, column, or box, then 5 cannot go there.
This process of ruling out impossible positions is the foundation of Sudoku solving. Later techniques simply organize that logic into useful patterns.
What are candidates?
A candidate is a digit that could still legally fit in an unsolved cell based on the information you currently have.
For example, if a cell cannot contain 1, 2, 3, 4, 5, 6, 7, or 9, then 8 is its only candidate. That creates a Naked Single, one of the first solving techniques most players learn.
Candidates become increasingly useful as puzzles get harder because they let you reason about possibilities before a cell is fully solved.
Does Sudoku always use a 9×9 grid?
Classic Sudoku is 9×9, but the basic idea can be adapted to other sizes and rule sets. Smaller grids such as 4×4 and 6×6 are often used for simpler experiences, while many Sudoku variants add extra regions or constraints.
VeyraPlay treats those experiences separately from the classic Sudoku knowledge base when they become distinct games or products.
Is Sudoku about guessing?
You can type a speculative number into a puzzle, but that is not the same as solving by logic.
The aim of logical solving is to make a placement or elimination because the current grid proves it is valid. Beginner puzzles may require only obvious deductions. Harder puzzles can require advanced techniques involving candidate patterns, links, or chains.
If you are new to Sudoku, focus first on understanding the grid and the rules. You do not need advanced techniques to begin.
Where should a beginner start?
A useful path is:
- Learn the Sudoku rules.
- Understand rows, columns, boxes, and cells.
- Learn how to scan the grid.
- Learn what candidates are.
- Practice Naked Singles and Hidden Singles.
- Move on to intermediate elimination techniques when simple placements stop appearing.
This is also the progression that the VeyraPlay Learn experience is designed to follow.
FAQ
What does Sudoku mean?
The name Sudoku became associated with the puzzle through Japanese publisher Nikoli. The puzzle itself existed earlier under the name Number Place.
Do you need to be good at math to play Sudoku?
No. Standard Sudoku does not require arithmetic. You need to track which digits are allowed in each row, column, box, and cell.
Can a Sudoku have more than one solution?
A partially filled grid can be constructed with multiple valid completions, but a standard published Sudoku is normally expected to have one intended solution. VeyraPlay should validate uniqueness for its classic puzzles.
What should I learn after the basic rules?
Learn how the grid works, then practice scanning, candidates, Naked Singles, and Hidden Singles.
What to learn next
If this is your first Sudoku, continue with Sudoku Rules and How to Play Sudoku. If you already know the rules but want to solve more confidently, move to How to Solve Sudoku and Sudoku Candidates.