What changes on Medium?
Medium drops ten of the starting numbers you saw on Easy. The dots do not change — every dot the answer implies is always drawn, on every level — so what changes is how much you have to lean on them. With fewer numbers to read against, you will find yourself reading the empty lines almost as often as the dots.
If Medium feels like a big jump from Easy, that is completely normal. Most kids spend a couple of weeks at Easy before Medium starts to click. For a refresher on the rules with picture guides, the Kropki Sudoku page has the full walk-through.
Three dot tricks to try
-
The staircase
Three squares in a row joined by white dots always make a staircase — like 3-4-5 or 7-6-5. The middle square can never be 1 or 9, and once you know one end, the whole thing falls.
-
Squeeze from both sides
When a square has filled neighbours on two sides, both lines clamp it at once. A square that is one away from 5 AND double-or-half of 3 can only be 6. A square that is one away from 5 with an EMPTY line to a 7 can only be 4.
-
The black-dot sweep
Before anything else, cross 5, 7 and 9 out of every square touching a black dot, and 1 out of every square touching a white dot. It takes thirty seconds and it removes a surprising number of candidates.
- 1. The middle square is one away from both of its neighbours.
- 2. The two end squares share a row, so they cannot be the same number: one is a step below the middle and the other a step above.
- 3. So three squares in a row joined by white dots always make a staircase, like 3-4-5 or 7-6-5 — and the middle square can never be 1 or 9.
How to spot a forced digit
A "forced digit" is when only one number can go in a square, no matter how you look at it. Spotting them is the main skill on Medium. Here is the order we recommend: check the row, check the column, check the 3×3 box, then check every line touching the square — the dots first, then the empty ones. If that leaves one number, write it in.
Sometimes the row and column leave three or four options and a single dot knocks out all but one. Sometimes it is an empty line that does it: next to a filled 6, an empty line rules out 3, 5 and 7 in one go. That is the pay-off for learning Kropki Sudoku — the lines really do the work for you.
When you get stuck
- ✏️ Turn on Auto Notes — it applies the dot shapes and reads every line next to a filled square for you
- 🔎 Tap Check to make sure every number you have written is still correct
- 💡 Tap Hint to fill one square (it counts in your stats, but that is okay!)
- ↻ Tap Undo to go back if something turned out wrong
Ready for the next step?
When Medium Kropki Sudoku puzzles take you under 10 minutes, give Hard Kropki Sudoku a try. Hard puzzles give you only eight starting numbers, and the empty lines start doing most of the work.
Frequently asked questions
How long should Medium Kropki Sudoku take?
Most kids finish a Medium puzzle in 10 to 20 minutes. If it takes longer, that is fine — use Notes and tap Check whenever you want to make sure you are on track.
Can I switch back to Easy?
Of course — just tap the Easy tab at the top of the board. Your Medium puzzle saves automatically and will be waiting when you come back.
Are there fewer dots on Medium?
No — every level shows every dot the answer implies. Medium simply gives you 26 starting numbers instead of 36, so you rely on the dots and the empty lines more.
Does Auto Notes take the dots into account?
Yes. Auto Notes only writes digits that are legal under all the rules at once, including the dot shapes and every line — dot or empty — next to a square you have filled, so your pencil marks are always correct.
Try other sudoku games
Different rules, same friendly board. Pick a sibling puzzle to play next.