How to play Hashiwokakero

Hashiwokakero—often shortened to Hashi or Bridges—is a logic puzzle about joining numbered islands into one network.

The rules

1. Bridges connect islands in the same row or column.
2. A bridge cannot turn, pass through another island, or cross another bridge.
3. At most two bridges may connect the same pair of islands.
4. An island’s number is the exact total of bridge lines touching it. A double bridge counts as two.
5. Every island must be connected, directly or indirectly, in one network.

Only the nearest visible island in a direction can be connected: a bridge cannot pass through an intervening island.

Your first deductions

Count how many bridge lines an island could possibly receive. A corner island marked 4 with only two neighbours needs double bridges to both. An island marked 1 can use only one line total, so once it connects, all its other directions are closed.

Do not satisfy numbers in isolation. A set of completed islands may still be wrong if it forms a separate network that can no longer join the rest.

A reliable solving routine

1. Find islands whose clue equals their maximum available bridge capacity.
2. Recalculate neighbours whenever a bridge reaches an island’s number.
3. Eliminate any possible bridge that would cross a confirmed one.
4. Keep at least one outward route from every partial group.
5. Near the end, check both exact clue totals and whole-network connectivity.

Controls on this site

Select one island and then a visible island in the same row or column. Repeating the pair cycles one bridge → two bridges → no bridge. Select the first island again to cancel. Your board is saved automatically in this browser.

Begin Riverworks or learn the Hashi solving techniques for tougher crossings.