# What Makes Sudoku Easy, Medium, Or Hard? Here’s The Science Behind Sudoku Levels

If you want to master Sudoku, you most likely wonder how Sudoku difficulty levels are established. The main idea behind this puzzle is that a partially filled 9 x 9 grid needs to receive a set of numbers from 1 to 9, so that in each row, column, and 3 x 3 sub-grid a specific number appears only once. But when it comes to classifying Sudoku levels based on their difficulty, there is an ongoing debate. Several research studies analyzed this game from a mathematical point of view, suggesting that its algorithmic properties are the ones that generate the challenge.

### Sudoku levels: the challenge explained

The number of revealed squares might indicate to you the difficulty or the challenge your Sudoku puzzle has. This means that the difficulty level of Sudoku puzzles can be described based on the number of tricks you need to discover to solve them:

• If you can solve Sudoku with only hidden singles, you are playing a Sudoku with an easy level.
• If your puzzle is all about pairs and triples, its challenge increases.

Of course, this depends on your skills and experience with mastering Sudoku puzzles. The difficulty of a Sudoku puzzle is related to the number of tricks such as x-wing, xy-wing, unique rectangles, and so on.

Easy and medium Sudoku puzzles can be understood and solved with the help of direct logical inferences. Moreover, the difficulty can be viewed as a manner of observing how many givens are in each row, column, or box, and how these can help you discover the correct place for each number missing.

• Easy Sudoku puzzles come with at least three in each row, column, box, and number, along with 30 givens.
• Hard Sudokus might come in the upper 20s, along with entire boxes or numbers unaccounted for.

And what is even more interesting, is that the hardest levels of Sudoku will make you use more than deduction. You will have to discover a number that may or may not be correct, which in turn might lead you to solve the Sudoku or start the quest again.

### The bottom line

Overall, there is no connection between the difficulty of a Sudoku puzzle and the clues featured. Everything is about the logic decisions, the redundancy, and the complexity of the game. Simple and easy Sudokus will allow you to discover the solution with a simple scanning technique. Keep in mind that the difference between easy, medium, and difficult puzzles depends mostly on your knowledge and level of experience with mastering Sudoku. Every Sudoku lover will tell you this is a great activity to improve your problem-solving skills and have fun!

So… start playing!