How To Play Sudoku

All you need to know on how to play sudoku!

Shown below is a few diagrams to illustrate how to play sudoku. The puzzle shown in the diagrams is a standard size of what we call a 3 x 3 grid puzzle. Some people may refer to it as a 9 x 9 grid puzzle. We actually have four different grid sizes among all of our four difficulty levels of puzzles. How to play our four different puzzle levels are explained in more detail below. For the purpose of explaining of how to play sudoku, we will use the 3 x 3 grid as shown in Figures 1 through 4 below.

First of all, each puzzle grid size will use a different set of numbers or letters to use in the puzzle. For this 3 x 3 grid puzzle, you need nine digits or nine letters. Our puzzles of this size use the numbers 1 through 9 for the numbers and on different puzzles we also use the following letters of the alphabet: A, B, C, D, E, F ,G ,H and I. The illustrations below show puzzles using the nine numbers. When letters are used instead, they must be completed in the same manner.

Figure 1

 

Figure 3

As shown in Figure 1, a typical 3 x 3 grid puzzle contains nine sets of nine boxes. Also, the puzzles will have some of the numbers filled in for you. What numbers are given is determined by the difficulty of the puzzle. One of the numbers 1 through 9 must be inserted into each box of each row and of each column as shown in Figure 2. The numbers can be used only once in each of the rows or columns. You do not need to worry about the numbers on the diagonal. Diagonals do not matter in this puzzle.

The numbers 1 through 9 must also appear only once in each of the nine block sets as shown in Figure 3. This is in addition to the numbers being used only once in the rows and columns. As you begin to enter numbers, you will see that through a process of elimination, you will be able to determine where other numbers need to go. When you are finished, your puzzle should contain the numbers 1 through 9 in every nine block set, every row and every column. A completed puzzle is shown in Figure 4. The different sizes and difficulty levels of our sudoku puzzles are described below.

Figure 2

 

Figure 4

As mentioned above, we have four different categories of free sudoku puzzles with four different levels of difficulty. Each level of our puzzles use a different grid size with a different set of numbers and/or letters in the puzzle.

Our "very easy" level of puzzles use a 2 x 2 grid. They will use the numbers 1 through 4 or the letters A,B, C and D. They are not mixed, any given puzzle in this category will use either numbers only or letters only. These are considered simple sudoku puzzles and would be a good place to start for a beginner.

Our "easy" puzzles use the 3 x 3 grid as shown in the sample illustrations above. They use either the numbers 1 through 9 or the letters A through I.

Our "medium" puzzles use a 4 x 4 grid. A 4 x 4 grid needs 16 digits or letters. In our medium level puzzles we use the numbers 0 through 9 in combination with the first six letters of the alphabet which are: A, B, C, D, E and F.

The most difficult category we have is the "hard" level. These puzzles use a 5 x 5 grid which means that they need 25 digits or letters. To avoid using double digit numbers, we use only letters for these puzzles. The letters used are all of the letters in the alphabet except for the letter "Z".