Summary: How to play Wordoku: it is letter Sudoku with a hidden word. The symbols are the distinct letters of one word. Fill every empty cell so each row, each column, and each box holds those letters exactly once. One row or column starts completely blank — on a board like this one, when you finish it, it spells the word. This guide uses a 6×6 board whose hidden line is STUDIO.
Overview
A Wordoku puzzle is a letter grid. Classic Wordoku takes one word with no repeated letters and uses those letters as the Sudoku symbols. On a 6×6 that is six letters; on this board they are S, T, U, D, I, and O. Thick lines mark the boxes. On 6×6 each box is two rows by three columns.
Left is the puzzle. Right is the finished solution. The shaded row is the hidden-word line. Cover the right-hand grid (or scroll it off-screen) while you work the left-hand grid. Count rows down from the top and columns left to right. The first fills are walked below.
The Goal
Fill every empty cell so each of the word’s letters appears once in every row, once in every column, and once in every box. On a board like this one, when the blank line is full, read it — that is the hidden word.
The Rules
- Use only the word’s letters, and never repeat one in a row, a column, or a box. This 6×6 uses S, T, U, D, I, and O. Each of those six letters appears once per row, once per column, and once per box.
- Printed starting letters do not move. They are already part of the answer. Fill only the empty cells.
- One row or column starts completely blank. That is the hidden-word line. On this board it is the shaded top row. Some pages hide the word in a column instead of a row.
- On a board like this one, the finished blank line spells the word. You do not have to know the word before you start. The same row, column, and box rules that fill the rest of the grid fill the blank line too. That is the default (Scramble Word off). If Scramble Word is on, the same line still starts blank and still uses each letter once, but the finished letters need not spell the source word.
- There is only one correct fill. Do not guess.
How to Play Wordoku
Work the left-hand 6×6. The top row is empty on purpose. When a box, row, or column has only one empty cell, that cell is the missing letter.
- Find a box with exactly one empty cell. The middle-left box (rows 3–4, columns 1–3) already shows T, U, S, I, and D. The one empty cell is row 4, column 2. The six letters minus those five leave O. Write O there.
- Find the next one-empty box. The bottom-right box (rows 5–6, columns 4–6) already shows O, D, I, U, and S. The one empty cell is row 6, column 6. The leftover letter is T. Write T there.
- After those two letters, look down each column. The only blank left in columns 1–3 is the shaded cell in row 1. Column 1 already has D, T, I, U, and O, so row 1, column 1 is S. You just wrote O in column 2, so that column now has I, U, O, S, and D — row 1, column 2 is T. Column 3 already has O, S, D, T, and I, so row 1, column 3 is U.
- Your turn — finish that row the same way. Cover the right-hand grid (or scroll it off-screen). Column 4 already has S, I, T, O, and U. Column 5 already has T, O, U, D, and S. Column 6 already has U, D, S, I, and the T you just wrote. Write the missing letter in each shaded cell. Uncover the solution only when your top row is full — it should read STUDIO.
Those first fills are row 4 column 2 = O, row 6 column 6 = T, then S, T, and U in the first three cells of the shaded row.
If you want to make these for a book or a site, Puzzle Maker Pro generates Wordoku. Start with How to get started with Puzzle Maker Pro – Wordoku, or see the Wordoku product page.
Other Wordoku Sizes and a Vertical Hidden Word
Printed Wordoku also comes in 4×4, 8×8, and 9×9. A 4×4 uses 2×2 boxes and a four-letter word. An 8×8 uses 2×4 boxes. A 9×9 uses 3×3 boxes. A book page is usually emptier than this teaching board. The hidden line can sit in a column instead of a row. The fill rules stay the same: each letter once per row, column, and box. On a default board the blank line spells the word.
Outcome
You can fill a letter grid with row, column, and box rules, then read the blank line as the hidden word. Want to make a set? Try the free demo, open the Wordoku product page, or continue with How to get started with Puzzle Maker Pro – Wordoku. The Wordoku Tutorials hub has both pages.
FAQ
How do you play Wordoku?
Fill the empty cells so each of the word’s letters appears once in every row, once in every column, and once in every box. The line that started blank is the hidden-word line. On a default board, read it when it is full — that is the word.
What is Wordoku?
Letter Sudoku with a hidden word. The letters come from one word with no repeats. You fill the grid so each letter appears once per row, column, and box. On a default board, the line that started blank spells the word.
Do I need to know the hidden word before I start?
No. Treat it as a letter grid first. The blank line fills from the same rules as every other row or column. Seeing a nearly-complete line can confirm a letter you already placed.
Can the hidden word sit in a column?
Yes. Some pages hide the word in a column instead of a row. The letters still appear once per row, column, and box.
Does every letter in the word have to be different?
On Classic Wordoku, yes. A 6×6 needs six distinct letters. A repeated letter cannot make that size.
What grid sizes does Wordoku use?
Classic pages are 4×4, 6×6, 8×8, or 9×9. This guide walks a 6×6. The box shape changes with the size (2×2, 2×3, 2×4, or 3×3); the once-per-row, once-per-column, once-per-box rule does not.