How to play Bridges

Join the islands with straight bridges so each island has as many bridges as its number, nothing crosses, and every island is connected. Also known as Hashiwokakero, Hashi, Chopsticks.

▶ Play Bridges ⊞ Open the solver

The rules

Each circle is an island with a number from 1 to 8.
Draw bridges between islands in straight lines, across or down. A bridge may not cross another bridge or pass over an island.
Two islands may be joined by one bridge or two (in the simpler version, only one).
Each island must have exactly as many bridges as its number, and all the islands must be connected into one group.

Playing Bridges on Puzzle Solvers

Choose classic (up to two bridges between islands) or the simpler one-bridge version, a size and a difficulty, then press New Puzzle.
Drag from an island towards a neighbour to add a bridge; do it again for a double; a third time removes it. You can also tap the gap between two islands. Right-click takes a bridge away.
Islands turn green when they have all their bridges. The Progress panel shows how many separate groups are left — the goal is one.
Hint adds a bridge and explains the reasoning.

Open the Bridges game →

Using the Bridges solver

Choose the size and whether up to two bridges or one may join a pair, then click each island’s square and type its number (or press Sample).
Press Solve and step through: islands that need every possible bridge, ‘at least one’ deductions, full islands, and bridges that would cut a group off.

Open the solver →

A worked example

A 3 sits in a corner with two neighbours. Two bridges is the most either neighbour can give, so the 3 needs at least one bridge to each of them — draw a single bridge both ways.

One neighbour is a 1: that 1 is now full. So the 3’s third bridge must go to its other neighbour, making that a double bridge.

Strategies

Count the neighbours. An 8 has four neighbours and needs two bridges to every one. A 6 in a corner-like spot with three neighbours needs two to each.
At least one each. A 5 with three neighbours can get at most 4 from any two of them, so it needs at least one bridge to the third — and in fact at least one to each.
Ones and twos. Two 1s can never be joined to each other, and a double bridge between two 2s would trap them: both pairs would be cut off from everything else.
Full islands. As soon as an island has all its bridges, its remaining directions are closed — which often forces its neighbours.
Keep it joined. Near the end, look for bridges that would leave a group of islands with no way to reach the rest.

Common mistakes

Drawing a bridge that crosses another one.
Finishing every island but leaving two separate groups.
Forgetting that a double bridge counts as two at both ends.

Where it comes from

Bridges was published by the Japanese puzzle company Nikoli as Hashiwokakero (‘build bridges’). It is a favourite in puzzle books and apps worldwide under names like Bridges, Hashi and Chopsticks.

Frequently asked questions

Can bridges go diagonally?

No — only straight across or straight down.

Do all islands have to be connected?

Yes. When the puzzle is finished you can travel from any island to any other along the bridges.

What is the one-bridge version?

A simpler variant for younger players where two islands share at most one bridge. Numbers are then never bigger than 4.

How do I solve a puzzle from a book?

Open the Bridges Solver, place each island and its number, and press Solve to step through every deduction.

Keep going

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