Hashi Puzzle
Numbered islands on a grid. Your job: connect them with horizontal and vertical bridges until every island's number matches its bridge count, nothing crosses, and the whole map is one connected group.
Hashi
7×7 grid. 8–12 islands. Forced bridges only.
Standard play. Timer runs. Hints available.
How it works
Hashi (also called Hashiwokakero, or just Bridges) is a Japanese logic puzzle. The grid has numbered circles (islands) scattered across it. You draw bridges between islands that share a row or column, with no island between them.
Each island's number tells you its total bridge count. You can place one or two bridges between any pair of neighbors, and bridges can't cross. When every island is satisfied and the whole map is connected, you're done.
Play modes
Classic
Timer runs. Up to 3 hints. Standard play.
Timed Trial
Beat the clock. Bigger grids get more time.
Challenge
No hints, no undo. Every bridge placement is final.
What is hashi?
Hashi is short for hashiwokakero, which translates roughly to “build bridges” in Japanese. In English you'll also see it called Bridges or, less commonly, Chopsticks. The puzzle was popularized by Nikoli, the same publisher behind Sudoku and KenKen.
You start with a rectangular grid where some cells contain numbered circles. These are islands. The numbers range from 1 to 8 and tell you how many bridges must connect to each island. Bridges run in straight horizontal or vertical lines between islands that have a clear path between them. You can place one bridge or two (a double bridge) between any pair of neighbors.
Three rules govern the solution: every island's bridges must add up to its number, no bridges may cross, and the entire map must form a single connected group. That last constraint is what separates hashi from simpler number-matching puzzles. You can't just satisfy each island independently; you need to plan the bridge layout so everything links together.
How to solve hashi puzzles
Techniques from beginner to advanced.
Start with forced bridges
Some bridges are locked in before you make a single decision. An island with value 1 and exactly one neighbor? That bridge exists. Value 8? Double bridges to all four neighbors, no exceptions. Value 7 with four neighbors? Every neighbor gets at least one bridge, and three of them need doubles. Scan the board for these first.
Count remaining capacity
For each island, subtract the bridges already placed from the island's value. That's still needed. Now count how many bridges its remaining neighbors can accept. If those two numbers match, all remaining connections are forced. This triggers cascades: satisfying one island often forces bridges on its neighbors.
Use elimination
When an island has more capacity than its remaining neighbors can absorb, at least one bridge to each neighbor is guaranteed. Suppose an island still needs 3 bridges and has two neighbors that can each accept up to 2. The total available is 4, the excess is 1, so each neighbor must get at least 1 bridge (2 minus 1 = 1 minimum each). Place those minimums and reassess.
Watch for isolation
Every solved hashi is one connected group. If removing a potential bridge would split the board into two disconnected halves, that bridge is required. This matters most on larger grids where clusters of islands can end up isolated if you're not careful.
Grid size progression
Easy uses 7x7 grids with 8 to 12 islands. The forced-bridge technique alone usually solves them. Medium expands to 10x10 and requires actual elimination. Hard puzzles go up to 15x15 and start testing connectivity reasoning. Expert and Einstein are 15x15 to 20x20 grids that chain deductions across the whole board.
If you've solved Sudoku or KenKen before, you already have the right mindset: look for what's forced, eliminate what's impossible, and never guess.