How to play Trail (Zip-style path puzzle)

Trail is a small grid with a few numbered cells on it. You draw a single line that passes through every cell exactly once and visits the numbers in order — 1, then 2, then 3 — without ever crossing a thick wall. Boards run from 5×5 to 7×7, and each one has exactly one trail that works.

The five rules

Drag from 1, or tap cell by cell, to draw one trail.

The trail must cover every cell exactly once.

Visit the numbers in order: 1 → 2 → 3…

The trail cannot cross a thick wall.

Tap any cell already on the trail to erase back to it.

One deduction, step by step

Trail is decided by the cells that have no choice. Before drawing anything, look for the places where the line can only do one thing.

A cell with one way out. The wall closes this corner on the right, and the edge of the board closes it above and to the left. The trail can only leave downwards, and that link is settled before anything else is drawn.

Corners are forced. A corner has two neighbours and the trail needs two — one in, one out. Unless the corner is where the trail starts or ends, both of its links are already part of the answer.

From one number to the next. If walls and used cells leave a single route from the 3 to the 4, that route is the trail. Three cells drawn without a decision to make.

Where to start

Start at the ends. The 1 and the highest number are where the trail begins and finishes, so each of them uses exactly one of its neighbours — every other cell on the board uses two.

Then read the walls. A wall does not just block a step: it can leave a cell with a single free neighbour, and that link is then part of the answer whatever else happens.

Corners next. A corner has two neighbours and needs two, so unless a corner is an endpoint, both of its links are forced — the cheapest two moves on the board.

And keep an eye on the cells you would strand. If drawing a link would leave some cell with no way in or out, that link is wrong, and you have learned something without erasing anything.

Questions people ask

Is Trail the same as Zip?

It is that puzzle, yes. It is a cousin of Numbrix and Hidato, which number every cell of the grid; here only a handful of cells are numbered and the work is drawing the path itself.

Can the trail cross itself?

No. Every cell is used exactly once, and the line never runs diagonally — only up, down, left and right.

What are the thick walls?

Edges the trail cannot cross. They are what makes the solution unique: the generator adds walls one at a time until exactly one trail is left.

How do I undo part of the trail?

Tap any cell already on the trail and it erases back to that cell. You do not need to unwind the whole thing to fix a wrong turn.

What changes between Easy, Medium and Hard?

The board grows — 5×5, 6×6, 7×7 — and so does the number of walls. Hard boards send the trail on long detours, but never ask you to guess.

Play it

Same daily board for everyone, or unlimited puzzles

Today's Trail Start on Easy (5×5)

How to play Trail