# Online Sudoku Resources

Derived from the Japanese phrase “Suji wa dokushin ni kagiru”, Sudoku roughly translates to “the numbers must be single” or “the numbers must occur only once”. The premise of this puzzle, with its deep roots in number placement, might seem elementary, but the challenge it presents to players worldwide is anything but trivial.

The Basics of Sudoku

Sudoku is a grid-based puzzle game that usually features a 9×9 grid divided into nine 3×3 squares. Each row, column, and square contains nine cells. The objective of the game is to fill all the empty cells in the grid with numbers from 1 to 9. However, each number can only appear once in each row, column, or 3×3 square. The puzzle starts with some cells already filled, providing clues for the player to start placing the remaining numbers.

History of Sudoku

The concept of Sudoku can be traced back to the “Latin square” concept in mathematics developed in the 18th century. But it wasn’t until the late 20th century that it took the modern form we’re familiar with today, initially popularized in Japan and later gaining worldwide recognition. Maki Kaji is considered the sudoku puzzle creator.

Japanese puzzle creator: Maki Kaji

Types of Sudoku

While the standard Sudoku puzzle is based on a 9×9 grid, variations abound to keep the game interesting. Some popular versions include:

1. Mini Sudoku: Features a smaller grid, typically 6×6 or 4×4.
2. Mega Sudoku: Involves larger grids, often 16×16 or 25×25.
3. Diagonal Sudoku: Standard rules apply, with the added condition that the main diagonals must also contain all numbers from 1 to 9.
4. Alphabet Sudoku: Instead of numbers, players must fill the grid with letters.

Why Play Sudoku?

Sudoku puzzles can provide numerous cognitive benefits. They promote logical thinking, improve concentration, and can also enhance memory. Plus, Sudoku is universally accessible. It doesn’t require any mathematical skills, only deductive reasoning, making it appealing to a wide audience.

Playing Sudoku Online

There are plenty of resources available for Sudoku lovers online, including free puzzle generators, mobile apps, and online communities. Here are a few popular options:

1. Web Sudoku: Offers billions of free Sudoku puzzles with difficulty levels ranging from easy to evil.
2. Sudoku.com: A great resource for both beginners and seasoned players, offering a variety of challenges and tips.
3. Sudoku Kingdom: Allows users to play Sudoku daily and also participate in a monthly contest.