How to play Slant Lines

Draw \ or / in every square so that each corner number counts the lines touching it, with no closed loops. Also known as Slant puzzle.

The rules

Choose a grid size and difficulty, then press New Puzzle.
Tap a square to cycle it: \, /, empty. Right-click goes the other way, or pick a line tool.
A number on a corner says how many lines touch that corner (0 to 4).
The lines may never close a loop. Hint shows the next line you can be sure of — and why.

A 0 sits on the left edge between two squares. Neither line may touch it, so the top square gets \ and the bottom square gets /.

Next to it, a 2 on the edge has only two squares around it — both lines must touch it.

0 and 4. A 0 means no line touches the corner; a 4 means all four lines do.
Edges and corners. A 1 on the edge has only two squares around it; a 2 on the edge means both lines touch it.
Count what is left. If a number already has enough lines, the rest must point away. If it needs every remaining line, they all point in.
Avoid loops. If a line would join two points that are already connected, it would close a loop — slant it the other way.

Miscounting which lines touch a corner — a \ touches the top-left and bottom-right corners, a / the top-right and bottom-left.
Missing a loop that runs through several squares.

Slant puzzles of this kind have appeared in Japanese and Western puzzle collections for decades. This version always has a unique answer.

Which corners does a line touch?

A \ touches the top-left and bottom-right corners of its square; a / touches the top-right and bottom-left.

Do I need a line in every square?

Yes — the puzzle is solved only when every square has a line.

Is there always one answer?

Yes — every puzzle is checked so that logic alone reaches the answer.