Word Sudoku (Code-doku)

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Perhaps you've run across Go Doku (or godoku), Wordoku, or Sudoku Word puzzles before. Those letter-based sudoku puzzles have a hidden word, usually down the diagonal. These puzzles are a variation on that idea that I developed during this project. Since then Top Notch has produced some similar puzzles as well as other sudoku puzzles and variants. They've coined the term code-doku for these hidden-message sudoku, and I've also adopted that term.

This page contains four puzzles that introduce you to the Code-Doku puzzles. There are links below to many additional puzzles. The most recent puzzle is Headline – Week Ending 09 Sep 2005 (A Moderate Super Code-Doku with overlapping grids).


   G    S R      C  
 C               G  
     H      G  A   T
        G      H   C
     E         G    
 G   C      S       
 M   G  H      E    
   A               M
   H      C M    S  

Solve the puzzle the same way that you'd solve a numeric sudoku. Each of the letters is found once in every row, column and 3×3 box. When you're done, copy the shaded squares in order from left to right, then from top to bottom. The result is a hidden message.

Here's a print-friendly version of this puzzle.

I'd like to know how you enjoy these puzzles. (This particular puzzle is not an easy one, but that's just the author's choice—it's not a consequence of the hidden message.)

          P C    A  
          L E    W  
     V  A      C L  
 S                 W
   W L         P V  
 E                 L
   A W      L  V    
   P    W E         
   C    P V         

Here's another hidden-message sudoku with a twist. The sudoku itself is not too difficult. There's a lesson in this sudoku that you'll need to know for some other puzzles that I'll post.

Here's a print-friendly version of this puzzle.

          K        E
 A   M  I           
   K    H   A  I   S
   E      I    T    
 K                 A
     S    A      E  
 H   K  M   E    A  
            I  E   H
 T        H         

This puzzle and the one following are not properly sudoku puzzles. "Sudoku" means "single number," and the solutions to these puzzles are not determined by letter placement alone. You need to find the solutions that reveal the hidden messages. Make sure you've done the previous puzzle before you tackle this one. This one has the same twist.

Here's a print-friendly version of this puzzle.

     T      D       
          S      L  
          L T  A    
 S *           E    
 D        I A       
 L   I             S
 *               I  
 E D           L   *
          A      D  

This puzzle has the final feature that I want to introduce. Sometimes a message has more than nine different letters. Each asterisk in the message represents some undetermined character. It may be a letter, a punctuation mark, or some other special character.

Place each of the characters A, D, E, I, L, S, T, and * once in each row, column and 3×3 box. When completed, the shaded squares will contain a hidden message, read from left to right and top to bottom. Each asterisk represents a character other than the letters in the puzzle. In this puzzle, at least one asterisk represents a punctuation character.

Here's a print-friendly version of this puzzle

You've now been introduced to this style of puzzle. If you've enjoyed them, come back and check for more.

Additional Puzzles

Headline – Week Ending 02 Sep 2005 (An Easy Super Code-Doku with overlapping grids)
A Good Time For Sudoku (A Super Code-Doku with overlapping grids)
Beatles Songs (A series of 12 puzzles with varying difficulty.)
Under The Big Top (Difficulty: Moderate)
Enough Said (Difficulty: Tough)

Other Sudoku Resources

Top 50 Sudoku Sites -- A collection of links to sudoku puzzles, solvers, games and more.

Please send responses to my email address is mathrec at this domain