How to Play Sudoku
New to Sudoku? You are in the right place. Sudoku is a number-placement puzzle with just one rule, and once you have seen it done a few times it becomes wonderfully intuitive — no maths, no luck, just step-by-step logic. This guide walks you through the rule, how to read the board and the exact moves to make first, so you can sit down and solve your first grid today.
How to play Sudoku, step by step
- Get to know the grid — a Sudoku is a 9×9 grid split into nine smaller 3×3 boxes. Some cells already hold numbers (the “givens”); the rest are blank for you to fill.
- Learn the one rule — every row, every column and every 3×3 box must contain the digits 1 to 9 exactly once, with no digit repeating inside the same row, column or box.
- Pick a digit and scan — choose a number such as 1, then look across the rows, columns and boxes where it already appears. Often a box has only one empty cell where that 1 can legally go.
- Fill in the forced cells first — whenever a cell can hold only one possible digit, write it in. These certain moves open up the next ones, like a row of dominoes.
- Use pencil marks when you stall — in each empty cell, note the digits that could still go there. Working from these candidates turns a stuck grid into a chain of small deductions.
- Never guess — a proper Sudoku always has one logical next move and exactly one solution, so if you are unsure, keep scanning rather than gambling. The answer is always findable by reason.
- Finish and check — keep placing forced digits until the grid is full. If every row, column and box holds 1 to 9 with no repeats, you have solved it.
What is Sudoku?
Sudoku is a logic puzzle played on a 9×9 grid, where your goal is to fill every empty cell with a digit from 1 to 9 so that no digit repeats in any row, column or 3×3 box. That single goal is the entire game. The puzzle hands you a few starting numbers, and from those you deduce all the rest — there is no counting, no adding and no guessing involved.
Because the digits never interact arithmetically, you do not need to be good at maths to play. The numbers 1–9 are really just nine different symbols; you could play with nine colours or nine letters and the logic would be identical. What matters is where each symbol can and cannot go.
Reading the grid: rows, columns and boxes
A Sudoku grid has three kinds of group — called units — and each one must contain 1 to 9 exactly once: the nine horizontal rows, the nine vertical columns, and the nine bold-bordered 3×3 boxes.
- A row runs left to right across the whole grid — nine cells.
- A column runs top to bottom — nine cells.
- A box is one of the nine 3×3 blocks marked off by the thicker borders.
Every cell belongs to one row, one column and one box at the same time, so placing a digit affects all three groups at once. Beginners often watch only the rows and columns and forget the boxes — keeping all three in mind is the real key to playing well.
Your first move: scanning
The easiest way to start is scanning: pick one digit, find where it already appears, and let those copies rule it out of other rows, columns and boxes until only one cell is left for it.
Suppose the top-left 3×3 box has no 5 yet and has three empty cells. If two of those cells sit in rows or columns that already contain a 5 somewhere else, a 5 cannot go there — leaving only the third cell. That cell must be 5. You have placed a digit using nothing but elimination, and that new 5 may now create the same situation elsewhere.
Scanning alone will carry you through most Easy puzzles. Repeat it digit by digit, box by box, and the grid steadily fills itself in.
Beginner tips that make Sudoku easier
- Start with the most crowded areas. Rows, columns or boxes that are already nearly full have the fewest possibilities, so they give up their answers first.
- Hunt for the missing digit. If a box already holds eight numbers, the ninth is forced — fill it instantly.
- Work one digit at a time. Sweeping the whole grid for just the 1s, then the 2s, keeps your eyes focused and reveals forced cells you would otherwise miss.
- Pencil in candidates before committing. On tougher boards, noting the possible digits in a cell prevents mistakes and exposes patterns.
- Begin on Easy. A board with more givens lets you practise scanning before you ever need advanced moves.
Sudoku for beginners: FAQ
Is Sudoku hard to learn?
No. Sudoku has only one rule — fill every row, column and 3×3 box with the digits 1 to 9 without repeating — and most people are placing numbers confidently within their first Easy puzzle. The challenge grows with the difficulty level, not with the rules.
Do you need to be good at maths to play Sudoku?
Not at all. Sudoku never asks you to add or count — the digits 1–9 are just nine distinct symbols. It is a pure logic puzzle, so anyone who can spot patterns can play, whatever their maths ability.
Where should a beginner start?
Start on Easy, which gives you more starting numbers and can be solved by scanning alone. Learn to place forced digits confidently there, then move up to Medium and Hard as spotting the next move gets trickier.
How long does a Sudoku take to solve?
An Easy grid takes most players five to ten minutes; a Hard one can take half an hour or more of focused deduction. There is no clock unless you want one — Sudoku is as quick or as leisurely as you like.
Can every Sudoku be solved without guessing?
A properly made Sudoku has exactly one solution reachable by logic alone, so you never need to guess. Every board here is generated and checked to guarantee that single, logical solution.