Diagonal 3s
Two 3s touching only at a corner: the two outer sides of each — the ones away from the shared dot — are all lines.
How it works
- 1These 3s don't share an edge, only a dot — but that dot's four edges are exactly these two cells' sides: the upper 3's bottom and right, the lower 3's top and left.
- 2Every dot carries 0 or 2 lines. It can't be 0 here: that would blank two of the upper 3's sides at once, leaving it only two to work with. It can't be the upper 3's own two either, since that blanks both of the lower 3's sides and strands it the same way.
- 3So the two lines at that dot are one from each cell — meaning each 3's single blank side is one of the two it points at the dot.
- 4Both OUTER sides of each 3 are therefore lines: the upper 3's top and left, the lower 3's bottom and right. Four edges from two clues that never touch.
- Edge the technique adds
- Cells that establish the pattern