Visual primer for first-time solvers
Nurikabe,
shown not told.
Live demonstrationStep 01 / 07
Step01—Meet the board
This is Nurikabe.
A 5×5 grid with five numbered clues. Each number tells you the size of that island — how many white cells it contains, including the clue cell itself. All non-island cells form the sea: a single connected black region with no 2×2 pools anywhere.
Rules in play
- Each island's size matches its clue number
- Islands from different clues never touch orthogonally
- All black cells form one connected region
- No 2×2 block of cells may be entirely black
Clue cell
White cell with a number. The island it belongs to must contain exactly that many white cells total.
Sea cell
Black cell. All sea cells must connect into one region. No 2×2 block may be all black.
2×2 rule
Three black corners → the fourth must be white. Use this to force island cells.