Nurikabe

About Nurikabe

A Japanese logic puzzle where you shade cells black to form a connected sea. Each numbered cell is part of a white island containing exactly that many cells. No 2x2 block of black cells is allowed.

Description provided by GameZipper.

How to play

1. Numbered cells are the seeds of white islands. Each number shows the exact size of that island (the numbered cell plus its connecting white cells).
2. Click a cell to shade it black (the sea) or right-click to mark it as definitely white. The sea must be orthogonally connected as one region.
3. No 2x2 block of black cells is allowed. If three corners of a 2x2 are black, the fourth must be white.
4. White islands cannot touch each other orthogonally. They may only touch diagonally. Each island must contain exactly one clue equal to its size.
5. The puzzle is solved when all clues are in correctly-sized isolated islands and all remaining cells form a single connected black sea with no 2x2 blocks.

Controls

This game supports touch, keyboard, mouse input; the exact controls are explained inside the game.

Questions

What is Nurikabe?

Nurikabe is a Japanese logic puzzle published by Nikoli. You shade cells black to form a connected sea while keeping numbered cells in isolated white islands of matching size. No 2x2 block of black cells is allowed.

How do Nurikabe rules work?

1) Shade cells black to form one connected sea. 2) Each numbered cell belongs to a white island of exactly that size. 3) Islands cannot touch each other orthogonally. 4) No 2x2 block of black cells is allowed.

Is Nurikabe difficult to learn?

Nurikabe is easy to learn but challenging to master. Start with 5x5 grids and work up to 12x12. Key strategies: any cell that would create a 2x2 black must be white, and numbered cells force specific island shapes.