## Introduction to 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 features that are special to Code-Doku.

Enjoy!

 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 A, C, E, G, H, M, R, S and T 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.

This particular puzzle is not an easy one, unless you use the hidden message to help with the solution.

 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 the other puzzles on this site.

Place each of the letters A, C, E, L, P, S, V and W exactly once in each row, column and 3×3 box.

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.

Place each of the letters A, E, H, I, K, M, S, and T exactly once in each row, column and 3×3 box.

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

 R O T H S S * O A * R H * E R O R S T E E T A O * S A S

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. In general, an asterisk may be a letter, a punctuation mark, or some other special character. In this puzzle, each asterisk represents a letter other than the seven letters given in the puzzle. Like most of the other puzzles on this site, this one has a title that goes with the hidden message and a difficulty rating.

#### Under The Big Top

Place each of the characters A, E, H, O, R, S, T, and * exactly once in each row, column and 3×3 box. You will not be able to complete the puzzle using the sudoku rules alone. You will have to make choices that give a meaningful message.

Difficulty: Moderate

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

You've now been introduced to this style of puzzle. If you've enjoyed them, you can try the current puzzles or work through the Code-Doku archive