Completing Your First Sudoku: A Beginner’s Guide

If you’ve ever looked at a Sudoku puzzle and thought, “Where do I even start?”, you’re not alone. Sudoku may seem intimidating at first glance — a grid full of numbers, empty boxes, and endless possibilities. But once you understand the rules and a few simple strategies, you’ll discover it’s less about guessing and more about logical thinking.

In this guide, we’ll walk you step-by-step through completing your very first Sudoku puzzle — and enjoying the process along the way.

What is Sudoku?

Sudoku is a logic-based number puzzle played on a 9x9 grid, divided into nine 3x3 boxes. The goal is simple: fill every square with a number from 1 to 9 without repeating any number in the same row, column, or 3x3 box.

Step 1: Start with the Easy Clues

Every Sudoku puzzle begins with a set of numbers already filled in.
Your first step is to look for the “givens” that stand out — rows, columns, or boxes that are almost complete.

💡 Tip: The easiest starting point is a row, column, or box with only one number missing. Fill that in straight away — it’s a quick win that builds momentum.

Step 2: Use the “Crosshatching” Method

This beginner-friendly strategy works by scanning rows and columns to narrow down where a number can go.

Example: If you’re trying to place the number 5 in a box, check the other boxes in the same rows and columns. Wherever a 5 already exists, you can eliminate that square from consideration. The remaining square is your answer.

Step 3: Pencil Marks Are Your Friend

When you’re unsure, use pencil marks (small notes in a square) to keep track of possible numbers.
This isn’t guessing — it’s organised thinking. As you fill in other squares, you’ll naturally eliminate incorrect options until only one remains.

Step 4: Work Methodically

Sudoku rewards patience. Move systematically:

1. Scan for easy completions.
2. Use crosshatching to find logical placements.
3. Update pencil marks as you go.
4. Cycle through numbers 1–9, focusing on one at a time.

Step 5: Avoid Guessing

Many beginners get stuck and resort to random guesses. While tempting, this often leads to errors you’ll have to undo.
Instead, take a step back, look at the puzzle from a fresh perspective, and reapply your strategies.

Step 6: Celebrate Your First Completion

When you finally place that last number, take a moment to appreciate the accomplishment. You’ve not only solved a puzzle — you’ve learned the core logic behind Sudoku.

From here, you can start tackling slightly harder puzzles, experiment with timed challenges, and even compete with friends in Sudoku Social’s multiplayer mode.

Final Thoughts

Completing your first Sudoku isn’t about speed — it’s about understanding the process.
By starting with simple strategies, using pencil marks, and avoiding random guesses, you’ll soon find that what once felt impossible is now an enjoyable daily habit.

🔗 Ready to put your new skills into action? Try today’s free puzzle on Sudoku Social and see how quickly you can complete it.