All Sudoku Variants
9×9 · Misc

Wordoku

Also known as Letter Sudoku, Godoku

A normal 9×9 Sudoku using nine different letters instead of digits — often with a hidden word in the finished grid.

E D U C A T I O N

An example Wordoku: nine distinct letters replace 1–9 — here the word EDUCATION reads down the diagonal.

Wordoku is Classic Sudoku wearing a disguise: instead of the digits 1–9 it uses nine different letters. Every row, column and box must contain each of the nine letters exactly once, precisely as with numbers. The twist is purely cosmetic — but many Wordokus are built so that a hidden word reads out along a row, column or diagonal when the grid is finished.

The rule: nine letters, same logic

Pick a nine-letter set with no repeats — a word like EDUCATION works perfectly, since all nine of its letters are different. Then solve exactly as you would a number grid: each letter appears once per row, once per column and once per box. Below, a single box is filled with the nine letters of EDUCATION.

E D U C A T I O N

Nine distinct letters (here EDUCATION) stand in for 1–9 — each appears once per row, column and box.

It is the same puzzle underneath

Because the letters are just labels, a Wordoku is identical to a number Sudoku — map each letter to a digit and the logic does not change one bit. Every technique you know, from hidden singles to X-Wings, works exactly as before. The mapping below shows the same box with EDUCATION swapped for 1–9 in letter order; the deductions are the same on either side.

1 2 3 4 5 6 7 8 9

The very same box as numbers (E=1, D=2, U=3 … N=9). Letters or digits, the puzzle is one and the same.

The hidden word

Setters often choose the nine letters so that a themed word appears along a line of the solved grid — commonly the main diagonal or a central row. It is a nice reward, but it is a reward, not a solving tool: guessing the word and forcing letters to fit is exactly the kind of leap that leads to contradictions. Solve the grid with pure logic and let the word reveal itself at the end.

Solving strategy

  • Treat letters as digits. Mentally map them to 1–9 if it helps — the scanning and elimination are unchanged.
  • Don't chase the word. The hidden word is a bonus; forcing it undermines the logic.
  • Watch for look-alikes. Similar-shaped letters (O and Q, I and L) are easy to misread — check the given letter set carefully.
  • Use every ordinary technique. Hidden singles, naked pairs and the rest all transfer directly from number Sudoku.

Common mistakes

  • Assuming the word helps. The theme word is decorative; leaning on it invites errors.
  • Misreading a repeated-looking letter. All nine letters are different — if a word seems to repeat one, the puzzle uses a different letter set.
  • Overcomplicating it. Wordoku is not harder than the equivalent number grid; it only looks unfamiliar.
  • Forgetting the box rule. Each letter appears once per box as well as per row and column — the same three constraints as always.

Can I play it here?

Not yet — Wordoku isn't one of the puzzle types SudokuStreak generates for now. But you can learn its rules above, and there's plenty here to sink your teeth into meanwhile: