Strategy guides · Number path online
How to solve number path puzzles: rules and strategies
In a number path puzzle you draw a single line that passes every number in order and covers the whole board. Threadline adds thick walls the line can't cross. The trick is to find the cells where the line has no choice.
The rules
Start at 1 and draw one continuous line through every cell exactly once, moving up, down, left or right. The line visits the numbers in order and ends on the last one. It can't cross a thick wall.
1. Corners and boxed-in cells
A corner cell has only two neighbors, so the line must come in through one and leave through the other. The same goes for any cell with walls on two sides. Draw those forced pieces first; they often chain into long fixed stretches.
2. Don't leave pockets
If your line cuts off a group of cells that it can only enter once, it can never come back out, so that pocket must contain the end of the line. Since the end is fixed on the last number, any pocket without it means a wrong turn.
3. Count the steps between numbers
The line between two numbers has to cover all the cells that no other part of the path will visit. If 3 and 4 are close but a whole area lies between them and nothing else, the line must wander through that area on the way.
4. Follow the edges
Lines along the border are safe to extend because they can't trap cells behind them. Work inward from the walls and corners, and the middle usually resolves itself.
Common mistakes
- Rushing from one number to the next by the shortest route and stranding cells.
- Forgetting that walls block movement just like the board's edge.
- Erasing everything after one mistake. Back up only to the last forced move.