How to play Arrow Loop

Shade some squares and draw one loop through all the others, so that arrows count the shaded squares in their direction and shaded squares never touch. Also known as Arrow-and-loop puzzle, shade-and-loop puzzle.

▶ Play Arrow Loop ⊞ Open the solver

The rules

Every square that isn’t a clue is either shaded or on the loop.
The loop is a single closed path through square centres, moving across or down, never crossing or branching.
Shaded squares never share a side.
An arrow’s number is the count of shaded squares in that direction, all the way to the edge of the grid.

Playing Arrow Loop on Puzzle Solvers

Choose a size and a difficulty, then press New Puzzle.
With Draw loop, drag from square to square to draw the loop; drag back over a segment to rub it out. Tap a square to shade it.
Use Shade and Not shaded to mark squares, or right-click for a dot.
Arrow numbers turn green when they’re satisfied. Hint explains the next deduction.

Open the Arrow Loop game →

Using the Arrow Loop solver

Choose the size and enter the arrow clues (or press Sample).
Press Solve and step through: arrow counts, no touching, two joins per square and the one-loop rule.

Open the solver →

A worked example

A 2↓ arrow with three squares below it: the shaded squares can’t touch, so they are the top and bottom squares and the middle one is on the loop.

A loop square in a corner can only leave by its two open sides, so both joins are drawn — and if one of those neighbours is a clue, the corner square can’t be on the loop at all, so it’s shaded.

Strategies

Zeros first. A 0 arrow means every square that way is on the loop.
Corners. A corner square on the loop has only one way to turn — and a square boxed in by shaded squares and clues can’t be on the loop, so it’s shaded.
No touching. Next to a shaded square every square is on the loop (or a clue).
Dead ends. A loop square with only two open sides uses both of them.
One loop. Never close a small loop while squares are still left outside it.

Common mistakes

Counting the clue squares themselves, or squares past another clue, wrongly — only shaded squares count.
Closing the loop early and leaving squares stranded.
Shading two squares side by side.

Where it comes from

Loop-and-shading puzzles with arrow clues come from the Japanese pencil-puzzle tradition and became popular worldwide through puzzle championships.

Frequently asked questions

Do clue squares block the arrow’s count?

No — the count runs all the way to the edge; clue squares along the way are simply skipped.

Can the loop pass through a clue?

No — clue squares are neither shaded nor on the loop.

Is there always one answer?

Yes — every puzzle here is checked to have exactly one solution.

How do I solve one from a book?

Open the Arrow Loop Solver, enter the clues and press Solve.

Keep going

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