How Do You Play Sudoku?
Sudoku is a logic puzzle that has become popular worldwide. In this comprehensive guide, you'll learn everything you need to know to play sudoku, from basics to advanced techniques.
What is Sudoku?
Sudoku is a number game on a 9x9 grid, divided into nine 3x3 blocks. The goal is to fill each cell with a number from 1 to 9, where each number can only appear once in each row, column, and 3x3 block.
The Basic Rules
- Each number (1-9) can only appear once in each row
- Each number can only appear once in each column
- Each number can only appear once in each 3x3 block
- You start with a partially filled grid
- There is always one unique solution
Step-by-Step Getting Started
Step 1: Scan the grid
Start by looking at the entire grid. Look for rows, columns, or blocks where many numbers are already filled in - the easiest solutions are often found here.
Step 2: Look for "naked singles"
A "naked single" is a cell where only one number is possible because all other numbers already appear in the same row, column, or block.
Step 3: Use notes
Write small candidate numbers in cells where you're not sure yet. This helps you recognize patterns and make eliminations.
Step 4: Eliminate possibilities
When you place a number, remove it as a candidate from all cells in the same row, column, and block.
Basic Techniques
Last Position
If eight of the nine numbers are filled in a row, column, or block, the missing number must go in the last empty cell.
Row/Column Scan
Look for a number that's missing in a block. Check which rows and columns already contain that number to determine the possible position.
Box-Line Interaction
If a number can only be in one row or column within a block, it cannot appear elsewhere in that row or column outside the block.
Tips for Beginners
- Start with easy puzzles and work your way up
- Take your time - sudoku is not a race
- Use pencil or notes for candidates
- Check your work regularly
- If you get stuck, take a break and look again later