Nurikabe
Einstein
00:00
Classic
Einstein Nurikabe — what to expect
Einstein Nurikabe keeps Expert’s 11×11 board and goes one step deeper. Some cells yield to nothing shallower than a what-if: assume a colour, follow it until it contradicts itself, and take the opposite. Every puzzle is verified solvable by logic alone — the assumption always resolves, so you are never guessing.
How to play Nurikabe
- Every cell ends up one of two things: island, left white, or sea, shaded black.
- Each number is the SIZE of its island — that many white cells joined edge to edge, with the number itself counted among them.
- Every island holds exactly one number. So a 1 is finished where it stands, and the four cells beside it — above, below, left and right — are sea. Its corners are free.
- Two islands never sit side by side. Meeting at a corner is fine — a finished board is full of diagonal contacts.
- All the black cells join into one single sea. Nothing may be walled off from the rest of it.
- No 2×2 block may be entirely sea. When three corners of one are black the fourth has to be white, and that is where many boards open up.
- Every puzzle has one solution, reachable by logic alone, and every board has a move you can make from the empty grid.