The Rules of Sudoku

If you are a fan of logic puzzles then you may be aware by now of sudoku, the hottest new puzzle. Many of the world's top newspapers are carrying daily sudoku puzzles, and more publications for sudoku are available. The rules of sudoku are also easy to understand, and by knowing them the puzzle can be completed with ease, or it will at least be easier to handle tougher puzzles.

Sudoku is a Japanese term, where “su” means “number” and “doku” means “single place.” While the game first became popular in Japan in the 1980s it has gotten to be popular in North America and Europe in the twenty-first century.

Sudoku is a game where the goal is to get the puzzle completely filled. The puzzle consists of a 9x9 grid of squares that contains nine separate 3x3 grids linked together. There are some numbers in some of the empty squares, which are known as givens. The rest of the squares that are blank will need to be filled.

The numbers 1 to 9 will need to be placed throughout the empty boxes. However, each number can only be used once in a single row or column. Also, each number can be used only once in a single 3x3 grid.

There are various different difficulty levels that are used in sudoku, thus making this one of the logic puzzles that can be solved by people of different skill levels. For instance, a puzzle with more givens can be tough in that the positioning of the givens can make an impact on how well one will be able to solve the puzzle with ease. The difficult levels can be divided in easy, medium, hard and challenging skills.

There are also some different strategic methods used in logic puzzles that are common in sudoku. Scanning is a common technique in that cross-hatching can be used to check a region to see what numbers can be eliminated from the area. Counting the region is also useful in that missing numbers are identified.

Marking up is a common strategy. It is used in that possible numbers in a space are filled in on an empty space. Analysis is also used in that numbers from multiple cells are eliminated so that only one choice is left based on a check on the contingencies that are involved in the result. In some cases the solver will use a “what if” approach to try with one of two numbers in a box and if the number does not work initially then the other is used.

Those are the rules of sudoku to follow. As it can be seen this game is quickly becoming one of the most popular logic puzzles in that it is easy to play yet challenging to solve.

Chinese elements add interest to Sudoku competition - China Daily

China Daily

Chinese elements add interest to Sudoku competition China Daily By Zhang Yue (China Daily) "This is the first time that the binary system and mosaic, which are some of the concepts used in Chinese puzzles, have been used in an international Sudoku competition," says Chen Cen, the 27-year-old designer of both this ...

Sudoku 294 killer - The Guardian

The Guardian

Sudoku 294 killer The Guardian Normal sudoku rules apply, except the numbers in the cells contained within dotted lines add up to the figures in the corner. No number can be repeated within each shape formed by dotted lines. For a helping hand call our solutions line on 09068 338 ... and more »

Ateneo student places third in Beijing Sudoku tournament - GMA News

Ateneo student places third in Beijing Sudoku tournament GMA News Sarah Jane Cua, a student of the Ateneo de Manila University (ADMU), recently placed third in the under 18 category of the 2012 Beijing International Sudoku Tournament in Beijing, China. Cua, 16, an incoming second year Management Engineering student ...

Philippine Sudoku champ bags 3rd in China - Inquirer.net (blog)

Philippine Sudoku champ bags 3rd in China Inquirer.net (blog) Former national Sudoku champion Sarah Jane Cua proved her mastery of the logic-based number-placement puzzle one more time when she placed third in the youth category of the just concluded 2012 Beijing International Sudoko Tournament. and more »

Ateneo student wins 3rd in Beijing Sudoku tourney - ABS CBN News

Ateneo student wins 3rd in Beijing Sudoku tourney ABS CBN News MANILA, Philippines – A 16-year-old Ateneo de Manila University student secured the third place in the 2012 Beijing International Sudoku Tournament held in Beijing, China. Sarah Jane Cua won third place in the age 18 and under category of the contest.