How to Play Nurikabe

THE PLAYBOOK · CSQUAN

How to play Nurikabe

Use a short break to learn the rhythm of Nurikabe. Create one connected sea around numbered islands of exactly the stated size, without a 2×2 sea block. Check the relevant rule before repeating a move. Begin with the solo mode shown on the page. Choose a clear next step rather than rushing through the instructions.

Play ten compact 5×5 puzzles. Some boards begin with fixed shaded sea cells.

Focus on one rule

Choose one rule to keep in mind for this round. Apply it consistently rather than guessing what another version might allow. Refer to the controls when needed.

Your goal

Create one connected sea around numbered islands of exactly the stated size, without a 2×2 sea block. The feedback beside the game helps you follow the round. Take a moment to understand the current position.

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. On a smaller screen, keep the active part of the board within view. Use one clear input at a time.

A useful example

An island labelled 1 is already complete, so its edge neighbours must be sea. Focus on why the action is allowed, not only its outcome. Choose a deliberate next step.

Watch out for this

Two numbered islands may not merge into one. Take a moment to reassess the position before continuing. Before your first action, say what you are trying to achieve. Then compare the result with the goal.

Common questions