What “one key placement” means (and why you still think several steps)
The question sounds like this: where does 6 go in row 3? You choose one empty cell in that row. That placement completes the challenge.
In Sudoku Sama, “one key placement” means you answer a single question: where a particular number belongs in a given row on a 6×6 grid. Choosing that cell and confirming it completes the daily challenge. You do not fill every empty cell.
One answer ≠ one deduction
“One Move” and “one key placement” describe the completion goal. They are not a promise that the reasoning is always a single glance. The App Store subtitle, Daily Brain Teaser: One Move, is the same public language: one answer for the day, not one instant of thinking.
“One move” or “one key placement” describes your final answer, not how many thinking steps you need. Some puzzles take several exclusions—checking columns and 2×3 boxes—before only one legal cell remains. The how-to guide says this directly: some puzzles take several deductions before the target is clear.
What you are (and are not) asked to do
You do
- Read the question, which names a digit and a row.
- Check the row, the column, and the 2×3 box. The 6×6 rules define those constraints.
- Select one empty cell in that row, then confirm.
You do not
- Fill every empty cell.
- Race a timer.
- Play in the browser on this site. The daily puzzle is in the app.
How this differs from classic “finish the grid” Sudoku
Classic Sudoku asks you to complete the whole grid. Many mini puzzles do too. Sudoku Sama uses the same row, column, and box rules on a smaller board, but stops at the specified placement. There is no timer.
| Classic “finish the grid” | Sudoku Sama | |
|---|---|---|
| Goal | A fully filled valid grid | One specified placement |
| Grid | Commonly 9×9; some mini puzzles use 6×6 | 6×6 with 2×3 boxes |
| Timer | Depends on the puzzle you chose | No timer |
For the grid-size comparison itself, see mini Sudoku vs classic 9×9.
Why several empty cells can still leave only one legal place
A row can show several empty cells and still have only one legal home for the requested number. A 6 already in a column rules out that column. A 6 already in the 2×3 box rules out the rest of that box. After those exclusions, one cell can remain. That is hidden-single style thinking: you cross out illegal places instead of guessing.
This page does not paste a second teaching grid. The one-move example walks one original exclusion proof from start to finish.
After you place: HOW? and the science reading
HOW? shows a numbered fill-in. It is a step replay, not a written technique encyclopedia. The how-to page covers REVIEW and the rest of the controls.
Completing today’s puzzle unlocks a short science reading. Science readings are AI-generated editorial text based on linked NASA reference materials. NASA has not reviewed or endorsed these readings or this app.
FAQ
Is “one move” the same as guessing?
No. You prove the cell with the row, column, and box constraints. “One move” is the answer you submit, not a guess and not a promise that a single pencil mark always appears at once.
Can one placement still be hard?
Yes. One cell can still require several deductions. Multi-step logic is part of the puzzle.
Do I fill the rest of the grid?
No. The daily challenge ends at the specified placement.
Where can I see a full example?
Follow the worked one-move example.
Sudoku Sama is an English-language app for iPhone and iPad, requiring iOS or iPadOS 26 or later. It is a daily brain teaser: one move, one key placement, no timer.
Download Sudoku Sama on the App Store
About Sudoku Sama · How to play · Worked example · 6×6 rules