From WPC unofficial wiki

See Nurikabe for a different puzzle also sometimes called "Islands".


Shade in a polyomino in each thickly outlined region such that no two polymoinoes touch each other by a side, no two regions sharing an edge contain polyominoes of the same size, and a numbered region contains a polyomino of that size.

(Rules and example from WPC 2017 IB)

History of the puzzle[edit]

First appeared on Nikoli volume 117 (2006). Invented by 木兄 (Mokuani). Originally named 島国 (Shimaguni, lit. "Island country").

Appearances in the past WPCs[edit]