How to Play Nurikabe

THE PLAYBOOK · ZYCGLH

How to play Nurikabe

Nurikabe gives you a focused activity to play in your browser. Create one connected sea around numbered islands of exactly the stated size, without a 2×2 sea block. Use the example below to understand a decision. Keep the instructions close while learning this activity. Look at what changes after your first action.

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

Make the controls familiar

Locate the buttons and input area before beginning a long round. Use the on-screen labels to avoid an accidental restart. Make the next step deliberately.

Your goal

Create one connected sea around numbered islands of exactly the stated size, without a 2×2 sea block. An attractive position is not enough unless the goal is met. The example below illustrates a decision.

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 careful first action helps you become familiar with the layout. Use one clear input at a time.

A useful example

An island labelled 1 is already complete, so its edge neighbours must be sea. Compare this with the rule that governs the move. Verify the rule before continuing.

Watch out for this

Two numbered islands may not merge into one. Read the feedback to see why an action did not have the expected result. Watch the feedback after an action. A message can explain whether the input was accepted or whether a rule needs attention.

Common questions