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.