Bridges Puzzles
Join the islands with bridges until every number is satisfied and the map is one piece.
Hints available. Play as many boards as you like.
Ready when you are.
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Scan for the same board — no hints.
How to play
Each circle is an island, and its number says exactly how many bridges must meet it. Tap the water between two islands to add a bridge, tap again for a double bridge, and a third time to remove it.
Bridges run only straight up, down, left or right, never diagonally, and they may never cross one another. At most two bridges may join the same pair of islands.
The board is solved when every island's number is met and you can travel from any island to any other. An island satisfied but stranded from the rest is not a solution.
Strategy
Start with the islands that have only one way to go. An island marked 1 in a corner with a single neighbor must connect to it, and an island marked 4 with exactly two neighbors needs a double bridge to each. These forced starts cost nothing to find and open the map.
Then use the near-forced rule: an island whose number is one less than twice its available directions must take at least one bridge in every direction. A 3 with two neighbors, for example, must have at least a single bridge to each, even before you know which one doubles.
Keep connectivity in mind throughout, not at the end. If a group of islands would be sealed off by completing a bridge, that bridge is wrong even when every number still works out — this is the constraint that separates Bridges from ordinary counting puzzles.
Difficulty and variants
Easy places seven islands on a 7x7 map, medium nine on a 9x9, and hard twelve on the same 9x9 grid. The denser the map, the more crossings you must rule out, and the more the connectivity rule does the real work.
Questions, answered
What is a Bridges puzzle?
A map of numbered islands joined by horizontal and vertical bridges. Each island takes exactly as many bridges as its number, bridges never cross, at most two join any pair, and the finished network must connect every island.
Is Bridges the same as Hashiwokakero?
Yes. Hashiwokakero is the original name, often shortened to Hashi; Bridges is the usual English title for the same puzzle.
Can bridges cross each other?
No. If two bridges would intersect, at most one of them can exist, and ruling out crossings is a large part of the deduction.
Why is my board rejected when every number is right?
Almost always because the islands form two or more separate groups. The rules require a single connected network, not merely correct counts.