Hashi Rules: How to Play the Japanese Bridge Puzzle

Niels Glodny · 3 November 2026

Hashi is a logic puzzle played on a grid of numbered circles, called islands. You join the islands with bridges until every island has as many bridges as its number and all islands are connected to each other. The full Japanese name is Hashiwokakero (橋をかけろ), which means “build bridges!”. In English it is also sold as Bridges. It first appeared in 1990 in a Japanese puzzle magazine; the history of Hashi has the details.

The rules

1. Bridges run in straight lines, horizontally or vertically, between two islands.
2. At most two bridges join the same pair of islands.
3. Bridges never cross each other and never pass over an island.
4. The number on an island is how many bridges end there. A double bridge counts as two.
5. When the puzzle is finished, all islands form one connected network.

Every puzzle in this game has exactly one solution. The generator checks this before a puzzle is used.

Rules that are easy to misread

The number counts bridges, not neighbours. A 3 can be a double bridge to one island and a single bridge to another. An 8 is the largest possible number: four neighbours, a double bridge to each.

A bridge only reaches the nearest island. It cannot pass over an island to reach the one behind it. If two islands are in the same row with a third between them, each can only connect to the middle one.

Bridges do not turn. Two islands that are not in the same row or column can only be joined through other islands.

Matching every number is not enough. The board below has every number right, but the islands form two separate groups, so it is not solved. The only solution joins all four islands in a ring of single bridges.

In this game an island turns green as soon as it has the right number of bridges. Green says nothing about whether those bridges are the right ones, or whether the network is connected. If every island is green and the islands still form more than one group, the game tells you so.

How to play in this game

Tap between two islands to build a bridge. Tap again for a double bridge, and a third time to remove it. You can also swipe from one island to the next. Both work with a mouse and on a phone, and Settings can limit it to one of the two.

Puzzles range from 3×3 to 60×60. The campaign goes from 3×3 to 35×35, and custom mode makes boards up to 60×60. Larger boards follow the same rules. They are harder because there is more to keep track of.

Once the rules are clear, the next step is knowing where to put the first bridge. How to solve Hashi walks through the puzzle above, one move at a time.