DC Sudoku - How to Play

Micro Sudoku Puzzle
Micro (4x4) Sudoku

Mini Sudoku Puzzle
Mini (6x6) Sudoku

Icon for Sudoku+9 Sample #10
"+9" Samples

Icon for Easter Egg shaped puzzle
Special Occasions

Standard (9x9) Sudoku

Sudoku Strategy

Free Printable Books

Sample Puzzles

About DC Sudoku

How to Sudoku

Sudoku Humor


DC Sudoku Display Options

What the ???

The image to the right shows 3 different ways of displaying the same Sudoku puzzle. On the right is the standard version using the numbers 1..9. In the other two puzzles there is a simple equivalent between every number in the standard puzzle and a color or letter. For example, every 2 on the right is represented by a B in the middle and a blue square on the left. One could obviously make up many other equivalent representations using other colors, letters, symbols, etc.

Why these variations?

Why not?

A funny thing about Sudoku, the logic to solve each of the three puzzles above is identical, but different people will find different versions easier. It all depends on how your brain processes different kinds of information. So if your older brother is driving you mad with his skill at standard Sudoku, print one out in color, take a set of markers each, and see who's fastest now...

What are the Sudoku Rules?

A standard Sudoku puzzle has a single solution where every little square is filled with a color, number letter (etc.) - hereafter called "piece" such that:

  1. there are 9 pieces in total
  2. every row of 9 squares only has one of each piece
  3. every column of 9 squares only has one of each piece
  4. every 3x3 blockof squares inside the bold lines only has one of each piece

Some Strategy

To the left is shown the logic that will lead you to see that the piece wiuth the blue "x" must be blue. Notice
  • there is a blue square in the middle of the top 3x3 block
  • there is a blue square on the right of the middle 3x3 block
  • the two blue dotted lines show where there cannot be any other blue squares
  • therefore... the bottom 3x3 block must have a blue square on the left
  • since the other two square are already taken, the middle one must be blue
The DC Sudoku puzzles tagged as Beginner can be solved by repeatedly using rules like this. The more pieces you fill in, the easier the rest becomes.

The DC Sudoku puzzles tagged as Expert require much higher level logic than this to solve completely. Here are some sites that discuss more advanced Sudoku logic:

Sudoku Strategy Examples from DC Sudoku
Sudoku Strategy Hints Tips
Sudoku Strategy from "Sudoku Today"
Sudoku Solver
Wikipedia - Sudoku (includes some strategy)

Have fun!

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