GridbinderGridbinder · Bridges
Bridges puzzle book maker for KDP and e-ink
Bridges, the island and bridge puzzle, is a quiet favourite with solvers who like connecting things up. When we looked in October 2026, we found it only in a free PowerPoint pack, so a solid Bridges book can stand out.
Choose the levels, the trim size and the number of puzzles. Gridbinder makes the puzzles, the how-to page, the answer key and a Verification report in one PDF. The free 12-puzzle sample has a watermark and needs no account.
12 puzzles with your settings, watermarked, no account. Full books from $9 a month.
Why the proof matters here
A Bridges puzzle can hide a second way to join the islands, and the reader's bridges, all counted correctly, end up different from the answer key. Or the numbers can be satisfied only by a network that is split in two, which breaks the rule that every island must be reachable. Gridbinder searches each puzzle for a second solution and discards it if one exists, and a step-by-step solver has to finish it by logic.
Books end with a Verification report (on unless you switch it off): each puzzle with its level and size, the number of solutions a complete search found, and, for every type with a step-by-step solver, how it finished the puzzle.
Book ideas: A Bridges book for readers who like connecting puzzles; A progressive Bridges book from 7 x 7 up to 13 x 13; A connect-the-dots logic book mixing Bridges, Number Paths and Slitherlink.
How to solve, as printed in the book
Join the circles (islands) with straight bridges that run across or down, only between two islands in line with nothing between them.
The number on an island is how many bridges leave it. At most two bridges join the same pair of islands, bridges never cross, and in the end every island can be reached from every other.
| Easy | 7 x 7, 10 to 12 islands |
|---|---|
| Medium | 9 x 9, 16 to 20 islands |
| Hard | 11 x 11, 24 to 28 islands |
| Challenge | 13 x 13, 32 to 38 islands |
Questions
What grid sizes do the Bridges levels use?
Easy is 7 x 7, Medium 9 x 9, Hard 11 x 11 and Challenge 13 x 13. The generator aims for about 10 to 12 islands on Easy, 16 to 20 on Medium, 24 to 28 on Hard and 32 to 38 on Challenge.
What are the rules, as printed in the book?
Join the islands with straight bridges across or down. The number on an island is how many bridges leave it. At most two bridges join the same pair of islands, bridges never cross, and every island must be reachable from every other.
What makes Hard and Challenge harder?
More islands on a bigger grid, and Hard and Challenge puzzles may need a one-step what-if check. Easy and Medium use direct deductions only.
Other puzzle types
Sudoku · Killer Sudoku · Anti-Knight Sudoku · Nonogram · Slitherlink · Kakuro · Masyu · Nurikabe · Star Battle · Number Paths · Word Search · E-ink tablet PDFs
See your own pages first
The free sample uses your settings and real puzzles. Check every page before you pay anything.
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