How to Play The Free Online 9x9 Sudoku Game
Basic Rules:
- Fill each empty cell with a number from 1 to 9
- Each row must contain all numbers from 1 to 9
- Each column must contain all numbers from 1 to 9
- Each 3x3 box must contain all numbers from 1 to 9
- Some cells are pre-filled and cannot be modified
Controls:
- Click any empty cell to select it
- Use number buttons or keyboard (1-9) to input numbers
- Use Erase button or Backspace key to remove numbers
- Click "Check Solution" to verify your answers
- Click "New Game" to start a fresh puzzle
Scoring System:
- Starting score: 100 points
- Correct number: +1 point
- Incorrect number: -1 point
- Time penalty: -5 points every 30 seconds
- Game ends when score reaches 0
Visual Feedback:
- Green numbers: Correct placement
- Red numbers: Incorrect placement
- Gray numbers: Pre-filled cells (fixed)
- Blue highlight: Selected cell
Game End:
- Game ends when you click "Check Solution"
- Game ends when your score reaches 0
- Submit your score to the leaderboard
- Try to complete the puzzle quickly for a better score!
What is Sudoku?
Sudoku is a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9x9 grid with digits so that each column, each row, and each of the nine 3x3 subgrids (also known as boxes or regions) contain all of the digits from 1 to 9 without repeating any numbers.
History of Sudoku:
- Early Origins: The concept of placing numbers in a grid dates back to ancient civilizations. However, the modern form of Sudoku has its roots in the 18th century, with the publication of a similar puzzle called "Latin Squares" by the Swiss mathematician Leonhard Euler.
- Development in the 20th Century: The puzzle as we know it today was developed in the late 19th century. In 1979, Howard Garns, an American architect and puzzle constructor, created a puzzle called "Number Place," which was published in a Dell magazine. This puzzle was the prototype for modern Sudoku."
- Name and Popularization: The name "Sudoku" comes from the Japanese "Suuji wa dokushin ni kagiru," which means "the digits must be single." The puzzle gained popularity in Japan in the 1980s, where it was published in the newspaper Nikoli. It was in Japan that the puzzle was given the name "Sudoku"
- Global Spread: Sudoku became a global phenomenon in the early 2000s, particularly after it was featured in The Times, a British newspaper, in 2004. This led to a surge in its popularity, and it quickly spread to newspapers, books, and online platforms worldwide.
- Variations and Formats: Since its rise in popularity, numerous variations of Sudoku have been created, including different grid sizes, additional rules, and themed puzzles.
About 99Sudoku
Welcome to 99Sudoku.com, your go-to online destination for enjoying the classic game of Sudoku! Our website is dedicated to providing a fun, interactive, and user-friendly platform for Sudoku lovers of all ages and skill levels. Whether you’re a beginner just learning the ropes or a seasoned player looking for your next challenge, we have something for everyone.
Our Mission
At 99Sudoku, our mission is simple: to create an engaging and accessible space for Sudoku enthusiasts. We believe that playing Sudoku is not only a great way to relax and unwind but also an excellent exercise for the mind. Our goal is to make this beloved game available to everyone, anywhere, for free!
What We Offer
- Endless Puzzles: Dive into our extensive collection of 9x9 Sudoku puzzles, with varying levels of difficulty to suit your preferences. From easy to challenging, you can always find the perfect puzzle to match your skill level.
- User-Friendly Interface: Our website is designed with simplicity and ease of use in mind. You can start playing right away without any complicated setup—just click, play, and enjoy!
- Helpful Features: Take advantage of useful tools such as hints, notes, and the ability to save your progress, ensuring a smooth and enjoyable gaming experience.
- Community Engagement: Join our community of Sudoku fans! Connect with fellow players, share tips and tricks, and participate in discussions about strategies and favorite puzzles.
Why 9x9 Sudoku?
99Sudoku is more than just a game; it’s a fantastic way to enhance your cognitive abilities, improve concentration, and develop problem-solving skills. As you fill in the grid, you’ll find yourself immersed in a satisfying challenge that sharpens your mind and provides a sense of accomplishment.