How to Play Sudoku: A Step-by-Step Guide for Beginners

Sudoku looks intimidating the first time you see a grid full of numbers, but the rules fit in a sentence and the first solve clicks faster than most people expect. Here is everything a complete beginner needs.

Step 1: Understand the one goal

A Sudoku puzzle is a nine-by-nine grid. That large grid is split into nine smaller three-by-three squares, usually called boxes. Your single goal is this: fill in every empty cell so that the numbers 1 to 9 each appear exactly once in every row, exactly once in every column, and exactly once in every box.

That is the whole game. There is no addition, multiplication, or any other arithmetic. The numbers are really just nine different symbols — you could play with nine colours or nine letters and nothing would change. Sudoku is a puzzle of placement and logic, not maths.

Step 2: Learn to read the grid

Every cell belongs to three groups at once: one row, one column, and one box. This overlap is the key to the entire game. When you place a number, you are not just filling one cell — you are also removing that number as an option from every other cell in the same row, column, and box.

Before you write anything, get comfortable looking at the board in these three ways. Pick a number, say 5, and scan across to see which rows already contain a 5, which columns do, and which boxes do. On vSudoku you can tap any filled number and the board highlights every matching cell, which makes this scanning much easier while you learn.

Step 3: Make your first move — find a forced cell

The most satisfying beginner technique is finding a cell where only one number can possibly go. Here is how to hunt for one:

Choose a box that already has several numbers filled in.
Look at one of its empty cells.
Go through the digits 1 to 9 and ask, for each, “is this number already in this cell’s row, column, or box?”
If eight of the nine digits are blocked, the ninth is forced — it must go in that cell.

Placing a forced number often unlocks the next one, because the cell you just filled now blocks that digit elsewhere. Good beginner puzzles, like our Easy level, are designed so that you can chain these forced moves all the way to the finish.

Step 4: Try the “only place” method

The reverse approach is just as powerful. Instead of asking what fits in a cell, ask where a particular number can go in a box. Pick a box and a digit — say 7. If seven of the nine cells in that box are blocked (because a 7 already sits in their row or column, or they are filled), and only one empty cell remains, then 7 must go there. Switching between “which number fits this cell” and “where does this number fit” keeps you finding moves when one method stalls.

Step 5: Use pencil notes for the harder cells

When the easy forced moves run out, notes keep you organised. In each empty cell, pencil in every number that could legally go there. As you fill the grid, you remove candidates that are no longer possible. Patterns start to appear: a cell with only one candidate left is a guaranteed move, and a number that appears as a candidate in just one cell of a row must live there.

Turn on notes mode on vSudoku by pressing the pencil button or the N key, then tap numbers to add or remove them. Good note-keeping is the single biggest step up from beginner to confident solver.

Step 6: Never guess

A well-constructed Sudoku has exactly one solution and never requires guessing. If you feel the urge to guess, it almost always means there is a logical move you have not spotted yet. Slow down, re-scan the rows, columns, and boxes, and look again. Every puzzle on vSudokuis verified to be solvable by logic alone.

Controls on vSudoku

Click or tap a cell to select it, then enter a number with the on-screen keypad or your keyboard.
Keys 1–9 fill the selected cell; Backspace erases it.
N toggles notes mode; the arrow keys move your selection.
Undo steps back through your moves, and Hint reveals a cell if you are truly stuck.

Ready to play?

The fastest way to learn is to start. Open an Easy puzzle on the home page and try the forced-cell method on a few cells. When you want to go deeper, our tips and strategy guide covers the next set of techniques, and the rules page states the formal rules in full.