What is Fog Sudoku?
Fog Sudoku is a Sudoku where most of the grid starts hidden under fog. You can only solve the visible cells, and each correct number you place clears the fog around it, revealing new clues. The normal rules for rows, columns and boxes still apply.
In Marble Sudoku this mode is called Morning Mist. You can only play the open holes: a cloud just wobbles when you tap it. A wrong marble lifts nothing, so every move has to be a sure one.
- 9×9 board
- Classic rules
- Hidden clues
The rules
- 1Classic rules. Each row, column and 3×3 box holds every number once.
- 2Play the open holes. Covered holes cannot be played until their cloud lifts.
- 3Correct marbles lift clouds. Each right marble clears the clouds around it.
- 4Wrong marbles lift nothing. A mistake reveals no new clues.
Watch it on the board
- Clouds hide most of the board. You can only play the open holes.
- Each correct marble lifts the clouds around it, and the marbles hidden there come out.
- A wrong marble lifts nothing. Only the right colour clears the sky.
- Clear every cloud and fill all the holes to win.
Tips
- Start next to the open holes. The visible area is small, so look for the hole with the fewest options there.
- Use what the fog leaves out. Hidden cells still follow the rules. A colour that is visible in a row cannot appear again in its hidden part.
- Grow the clearing. Pick moves on the edge of the open area. They lift clouds over new cells and reveal the most.
- Be sure before you place. A wrong marble reveals nothing, so check the row, column and box first.
Fog Sudoku vs Classic Sudoku
| Fog (Morning Mist) | Classic | |
|---|---|---|
| What you see | A small open area at first | The whole grid |
| Clues | Revealed as you solve | All given at the start |
| Key skill | Working from a small window | Scanning the whole board |
Fog Sudoku FAQ
What are the rules of Fog Sudoku?
Normal Sudoku rules apply, but most cells start hidden. Placing a correct number clears the fog around it and reveals the clues underneath.
Can I play a hidden cell?
Not in Marble Sudoku. Only open holes can be played, and a cloud just wobbles when you tap it.
What happens if I place a wrong marble?
A wrong marble lifts nothing, so you gain no new information from it.
What is Morning Mist?
It is the Fog Sudoku mode in Marble Sudoku. Clouds drift over the wooden board, and correct marbles blow them away.
Is Fog Sudoku harder than Classic?
It feels different: you work with less information at a time. The puzzle still has one solution you can reach by logic.
PLAY IT IN MARBLE SUDOKU
Clear the Morning Mist
Start beside the open holes, lift the clouds marble by marble and watch the board appear.
Next modeBoulder Garden
