GridbinderGridbinder · Nurikabe
Nurikabe puzzle book maker for KDP and e-ink
Nurikabe readers like islands, a connected sea and a rule that punishes sloppy thinking. If you publish for them, each grid needs a single sea that every clue forces.
Set the levels, the trim size and the number of puzzles. Gridbinder makes the grids, 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
Nurikabe has more than one rule to check at once: island sizes, a single connected sea, no 2 x 2 block of shade. A weak puzzle can allow two different seas that obey all of them, and the reader's valid answer differs from the printed one. Gridbinder searches every grid for a second solution and discards it if one exists, and a step-by-step solver must finish it using rules a person can apply.
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 Nurikabe book for solvers who like shading puzzles; A progressive Nurikabe book from 6 x 6 to 12 x 12; A mixed gift book of Nurikabe, Nonogram and Sudoku.
How to solve, as printed in the book
Shade cells to form the sea. Every number belongs to one island of exactly that many unshaded cells, its own cell included, and each island holds one number.
Islands never touch side by side. All shaded cells form one connected sea, and no 2 x 2 block is entirely shaded.
| Easy | 6 x 6 |
|---|---|
| Medium | 8 x 8 |
| Hard | 10 x 10 |
| Challenge | 12 x 12 |
Questions
What grid sizes do the Nurikabe levels use?
Easy is 6 x 6, Medium 8 x 8, Hard 10 x 10 and Challenge 12 x 12.
How are the rules explained?
The how-to page says: shade cells to form the sea. Every number belongs to one island of exactly that many unshaded cells. Islands never touch side by side, all shaded cells form one connected sea, and no 2 x 2 block is entirely shaded.
What makes Hard and Challenge harder?
Bigger grids, 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 · Bridges · Masyu · 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.
Open the studio