Nurikabe is a binary determination puzzle in which the cells in a grid are split into either water (shaded) or land (unshaded).


The objective is to divide the grid into shaded and unshaded cells, subject to the following rules:

  1. Each numbered cell is an island cell, the number in it is the number of cells in that island.
  2. Each island contains exactly one numbered cell.
  3. There must be only one stream, which is not allowed to contain "pools", i.e. 2x2 areas of shaded cells.


A standard 10x10 nurikabe and its solution.

Nurikabe Example

Nurikabe Solution


Unless otherwise indicated, standard nurikabe rules apply to all variants.

Golem Grad: All water areas must be divisible into snakes with the heads and tails given in the grid. Snakes cannot cross each other.

Nurikabe Line: The rule that no 2x2 area of water is allowed is replaced with no 1x5 area of water is allowed.

Nurikabe Pairs: The island contains exactly two numbered clues, the sum giving the size of the island.