Bridges / Hashi
Why do correct island numbers not finish Bridges?
The totals are only one condition. All islands must also form one connected group. Bridges run horizontally or vertically without crossing; the default limit is two parallel bridges between neighbours.
Worked example
Two islands marked 1 can satisfy each other with one bridge, but that isolated pair is invalid when other islands remain outside it.
What to check on your board
Apply the rule above to your current board, then verify the remaining puzzle constraints. The example explains a local deduction; it is not a solution to every randomly generated board.
Checking your next move
After counting the bridges at each island, follow the connected islands as a group. If a group has no remaining way to reach the rest, its locally correct totals cannot be the solution. Check crossings separately: two bridge lines meeting between islands do not create a new island.
Using this reference
For Bridges / Hashi, read the rule and the worked example together before opening the game. Separate what the rule explicitly requires from what only seems likely on the current board. A useful next move is one you can explain from the visible constraints, not merely a pattern that looks familiar.
If you get stuck, isolate a smaller part of the position and list what is still possible there. After a move, check the affected rows, regions or connections again. The reference explains the documented rules; progress, controls and save behavior belong to the linked game.
Read the developer’s manual ↗ · Open the developer’s browser version ↗
Manual inspected: · Simon Tatham & contributors · MIT