--- title: "Medium Nurikabe: free printable with answers" description: "Free printable medium Nurikabe puzzles with answers. A nine by nine board where the two-by-two rule starts doing the work." source: "https://www.oncebooks.com/nurikabe/medium" --- 1. [Home](https://www.oncebooks.com/) 2. [Nurikabe](https://www.oncebooks.com/nurikabe) 3. Medium Free printable # Medium Nurikabe A medium Nurikabe is a nine by nine board with islands up to five squares. There is less that is forced at the start, so the two-by-two rule carries more of the solve: wherever three squares of a two-by-two block are shaded, the fourth belongs to an island. PuzzleDesign Difficulty A bigger board is harder, and so is letting one island grow larger, because a big island has more shapes it could take. Every puzzle shades exactly one way. 9×9 board, 17 islands. Each number is an island of that many squares, islands never touch, and what is left is one connected sea with no two-by-two block in it. Theme ClassicBoldSoftShadedNavyIndigoSkyTealEmeraldForestPlumBerryCrimsonEmberAmberCocoa **Customise colours** Numbers Cell lines Box lines Page background Style StandardClean Clean drops the title band and footer, leaving the grid. Generate puzzlePrint / save PDF Two pages: the puzzle and its answer. Every puzzle is proved to have exactly one answer by the same engine as our KDP studio. ## Want the whole book? This makes one puzzle. Sign up to turn it into a full Nurikabe book for Amazon KDP: hundreds of graded puzzles at any trim, as print-ready PDFs. [Build the full book](https://app.oncebooks.com/publisher-studio/nurikabe/edit?from=nurikabe&v=2&s=eyJkaWZmaWN1bHR5IjoiTUVESVVNIiwiY29sb3JUaGVtZSI6eyJ0aGVtZUlkIjoiY2xhc3NpYyIsIm92ZXJyaWRlcyI6e319fQ) Free to build · pay once to export Preview The puzzle and its answer, as they print. Hide the preview - Nurikabe Medium 1 Puzzle - Nurikabe Medium · Solution 2 Solution Generate puzzlePrint / save PDF ## How to solve a nurikabe Every number on the grid is an island of that many unshaded squares. Shade everything that is not an island, so that no two islands touch side by side, the shaded sea is all one piece, and no two-by-two block anywhere is entirely shaded. ### The method 1. Ring the ones first. A number 1 is an island all by itself, so every square touching it is sea. That is free, it costs nothing to check, and on most boards it opens two or three corners at once. 2. Shade between two numbers. Any square that touches two different numbers must be sea. Shading it would join them into one island, and an island is allowed only one number. This is the rule that fills in most of the middle of a board. 3. Use the two-by-two rule in reverse. Whenever three squares of a two-by-two block are shaded, the fourth cannot be, so it belongs to some island. Finding which island it belongs to is usually the next step, and often the only one available. 4. Ask what each number can still reach. A number of four can only ever use squares within three steps of itself, walking over squares that are not already sea or another island. A square no number on the board can reach is sea, however the rest of the puzzle turns out. 5. Close an island as soon as it is full. When an island has as many squares as its number, it is finished, so every square around it is sea. Mark those straight away: the sea they add usually triggers the two-by-two rule somewhere else. **The one rule people forget** The sea has to be a single connected region. It is easy to finish a board where every island is the right size and two pools of sea never meet, and that board is wrong. Check it at the end by tracing from any shaded square. **What the answer page shows** The same grid with every sea square shaded, so the islands stand out as the white shapes between them. **How the grades differ** A bigger board, and a larger cap on how big one island may get. A board of threes and fours is read almost by inspection; an island of nine or ten has a shape to work out, and that is where the time goes. **Is it the same as hitori?** No. Both shade squares and both keep the unshaded squares connected, but in hitori you shade duplicates and shaded squares may never touch, while here the shaded squares are meant to be one region and the numbers give island sizes. **Good for** Anyone who likes a puzzle that turns into a picture as it closes. ## Making a whole Nurikabe book? This page makes one puzzle. To publish a book on Amazon KDP, the [KDP Nurikabe maker](https://www.oncebooks.com/kdp-nurikabe-maker) generates hundreds of graded puzzles at any trim, as a print-ready 300 DPI interior and solutions PDF. ## More printable Nurikabe puzzles - [Easy Nurikabe](https://www.oncebooks.com/nurikabe/easy) - [Hard Nurikabe](https://www.oncebooks.com/nurikabe/hard) - [Expert Nurikabe](https://www.oncebooks.com/nurikabe/expert) - [Evil Nurikabe](https://www.oncebooks.com/nurikabe/evil) - [Nurikabe for beginners](https://www.oncebooks.com/nurikabe/for-beginners) - [Nurikabe island puzzles](https://www.oncebooks.com/nurikabe/island-puzzle) [See every printable Nurikabe](https://www.oncebooks.com/nurikabe) ## Questions **Are these medium nurikabe free to print?** Yes. Generate the puzzle above and print it with its answer, at no cost and with no sign-up. **Does every puzzle have one solution?** Yes. Most boards are not pinned by their own numbers, so the generator keeps only the ones a solver proves shade exactly one way. The answer is on the second page. **Can I make a Nurikabe book to sell on KDP?** Yes. The free tool makes one puzzle. The KDP Nurikabe maker generates hundreds of graded puzzles at any KDP trim, as a print-ready 300 DPI interior and solutions PDF.