Logic Masters Deutschland e.V.

Setters Initial Difficulty: 2/5, but could potentially drop to 1/5 after review.

Normal Sudoku rules apply.
Place the digits 1-9 so that they do not repeat in any row, column, or 3x3 box.

Fog of War
Most of the grid is covered in fog. Placing correct digits reveals the fog, no guessing is required.

Region Sum Lines
For each line, digits on the line have an equal sum N within each box it passes through. N can be different for each individual line.
Lines ALWAYS move orthogonally and do not branch.

Ratio Kropki
Cells seperated by black dots have values in 2:1 ratio.

Sandwich Sum
The clue outside the grid gives the sum of the digits between 1 and 9 in that row.

Hints available below - may only work on Desktop

To play this puzzle please click here: Play CTC

Hint - Where to start

Combining the 'secret' in Row 3 with the possible ways to make the sandwich sum work. It's perhaps easiest to think what digits can go in the sequence with the ratio kropki.