How to Play Nurikabe

THE PLAYBOOK · QTHCC

How to play Nurikabe

Nurikabe on QTHCC is organised around a clear objective: Create one connected sea around numbered islands of exactly the stated size, without a 2×2 sea block. Begin with learn from a completed round and use the playbook beside the game.

Ten checked compact 5×5 boards with fixed sea starters in some puzzles.

Learn from a completed round

Finish a round where possible, then identify one decision you would change. Revisit the example or mistake section for a focused second attempt.

Your goal

Create one connected sea around numbered islands of exactly the stated size, without a 2×2 sea block.

Step by step

1. Shade sea squares and leave islands white.
2. Every island contains exactly one clue.
3. Different islands cannot meet along an edge.
4. Check puzzle verifies sizes, connectivity and forbidden sea blocks.

Controls

Click or tap squares or graph edges. Number boards include a digit pad. Undo reverses the previous change; Check puzzle validates the solution.

A useful example

An island labelled 1 is already complete, so its edge neighbours must be sea.

Watch out for this

Two numbered islands may not merge into one.

Common questions