Dot Complete
Once two lines meet at a dot, every other edge touching that dot is an X.
How it works
- 1This dot already has two lines meeting at it.
- 2A loop can only pass through any dot once — degree 0 or 2, never more.
- 3Its other two edges are impossible now — mark them with an X.
- Edge on the loop
- Edge ruled out
- Cells that establish the pattern