Contrary
to what many people believe, Sudoku didn't actually originate in Japan.
The game was first published in the U.S. in 1979 under the name of
Number Place. Sudoku became popular
in Japan in 1986 under the name of
Sudoku,
and it has just started to actually become popular in the U.S. in 2005
with the new Japanese name. Sudoku is the abbreviation of a Japanese
phrase that means "the digits must remain single."
While some variations exist, a Sudoku puzzle is usually a 9×9
grid, made up of 3×3 subgrids, or "regions". Some cells
already contain numbers. These numbers are known as "givens".
As mentioned, the goal of Sudoku is to fill in the grid so that
every row, every column, and every 3x3
box contains the digits 1 through 9. The numbers in Sudoku puzzles are
only customary because no mathematics are involved with Sudoku, only
logic. Any set of nine different symbols may be used in place of the
digits 1 through 9, such as letters, shapes, or colors, but Sudoku
puzzles rarely use such symbols.
Every
Sudoku puzzle is designed so that there is only one solution.
Obviously, it is against the rules to alter the "given" numbers, so it
is necessary to work around those numbers. With any Sudoku-solving
method or methods, you will learn that it is always incredibly easy to
make a mistake. Once one mistake is made, a snowball effect of errors
occurs, and you usually won't notice the mistake until so many mistakes
have been made that you would either have to start over again of find a
way to take out your frustration in some way. Visit the "If You're
Frustrated" page for some
guidance in these situations.
The guides, tips, and methods featured on this site come in three
different sizes: Easy, Moderate, and Advanced. The easy methods are
obviously easier and take less time to learn, but they are sometimes
tedious and less effective. Consequently, the advanced methods are
obviously more difficult and take longer to learn, but they are some
quicker to use and more effective, if not necessary in some situations.
The moderate methods are, well...moderate. The methods I will show may
be applied at any point of solving a Sudoku puzzle when necessary. It's
impossible for me to show you every situation that the various methods
can be used in, so it is up to you to learn how to apply the various
methods effectively.
If you're just starting to learn about Sudoku, I recommend that you
read the
Easy Tips & Guides pages. If
those methods prove to be too easy or you master those techniques, feel
free to move on to the
Moderate Tips &
Guides or
Advanced Tips & Guides.