Mini Fog of War takes the hidden-board thrill of Fog of War Sudoku and fits it onto a friendly 6x6 grid with the digits 1 to 6. The board starts under fog with just one visible seed area; every correct digit clears the mist around it, and somewhere in the dark wait 2–3 surprise constraints — killer cages, kropki dots, thermometers, or arrows. It's free to play, finishes in minutes, and is the ideal introduction to the fog mechanic.
What is Mini Fog of War Sudoku?
Mini Fog of War is a 6x6 Sudoku hidden under a layer of fog. You fill the grid so that every row, every column, and every 2x3 box contains the digits 1 through 6 exactly once — the same rules as classic Mini Sudoku — but at the start you can only see one small area. Correct digits reveal the board as you go, uncovering givens, empty cells, and a couple of hidden bonus rules. Each puzzle has a single logical solution, and the fog never changes it — it only changes what you can see.
Mini Fog of War Rules
- Standard mini Sudoku rules: Every row, column, and 2x3 box must contain the digits 1–6 exactly once — including in cells still under fog.
- Seed reveal: The puzzle opens with a seed cell's 2x3 box, row, and column visible. The rest of the board is fogged.
- Correct digits clear fog: Each correct placement lifts the fog around its cell. Wrong digits reveal nothing.
- Surprise constraints: Each game hides 2–3 extra rules — killer cages, kropki dots, thermometers, or arrows — that appear as the fog clears and must be satisfied.
The Surprise Constraints on a 6x6 Grid
The hidden rules are the same four families as the full-size variant, but the 1–6 digit range makes each one sharper when it appears:
- Killer cages — digits sum to the target without repeating. With a maximum digit of 6, cage combinations are few: a two-cell cage summing to 11 must be 5+6. See Killer Sudoku rules.
- Kropki dots — white = consecutive, black = one digit double the other. On 1–6 the only black-dot pairs are 1-2, 2-4, and 3-6, so black dots are nearly decisive. See Mini Kropki.
- Thermometers — digits strictly increase from bulb to tip. A five-cell thermometer can only be 1-2-3-4-5 or 2-3-4-5-6. See Mini Thermo.
- Arrows — path digits sum to the circled cell. A three-cell path can total at most 6, so it's usually forced to 1, 2, and 3. See Mini Arrow.
Solving Strategies
1. Squeeze the seed area dry
Your opening box, row, and column intersect each other, so the visible givens constrain one another tightly. On six digits it's common to place several digits before touching the fog at all — and each one buys you a reveal.
2. Work the frontier, not the map
Focus on cells at the edge of the cleared area. They share units with digits you've already placed, making them the easiest to pin down — and solving them is what pushes the fog back.
3. Pounce on revealed constraints
When a cage, dot, thermometer, or arrow appears, apply its logic immediately. On a 1–6 grid these constraints are close to forcing: a black dot, a five-cell thermometer, or a small cage often resolves its cells on the spot.
4. Finish with classic scanning
Everything from classic Mini Sudoku applies on the visible board: cross-hatching, naked singles, and pairs place the digits that the fog logic narrows down.
Tips for Beginners
- Never guess into the fog. Wrong digits clear nothing. There is always a logical next move among the visible cells.
- Check fresh reveals before placing. A newly cleared cell may have brought a dot or cage edge with it — look before you commit a neighbouring digit.
- Use partially revealed shapes. Two cells of a thermometer already order themselves; one cage cell plus its sum already caps its partners.
- Let candidates do the bookkeeping. Automatic pencil marks in Sudoku - Brain Puzzles keep the frontier's options visible as the board grows.
- Step up when ready. The full 9x9 Fog of War uses the same rhythm with 2–4 hidden constraints and a much longer expedition.
Mini Fog of War is the friendliest way to experience Sudoku's most theatrical variant: a complete hidden-board adventure in a coffee-break package. Learn the reveal rhythm here, build the never-guess habit, and the full 9x9 fog will feel like a natural next expedition.