Dead End
Hard
Used by Smart Hint
A line can never just stop — every dot touches zero or two line segments. Draw a candidate edge and follow where the line is forced to go: if it gets driven into a dot whose other edges are all crossed off, it dies in a dead end, so the candidate edge is ruled out.
- Edge on the loop
- Edge ruled out
- Cells that establish the pattern
How it works
- Could the highlighted edge be part of the loop? Suppose it is, and follow only the two rules every beginner already uses: a dot touches zero or two lines (never one, never three), and a clue with its count complete crosses off its remaining sides.
- Each step is forced — the line has exactly one way to continue, so it gets pushed along the highlighted path, one edge at a time.
- A few steps in, the line is driven into a dot whose every other edge is already crossed off. It has nowhere to go — and a line can never just stop.
- A dead end means the supposition was wrong from the first stroke: cross off the highlighted edge. If you can spot the trapped pocket ahead of time, you don't even need to draw anything — the edge that leads into it can't be a line.