THE PLAYBOOK · SJBOB
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. Treat the first round as a chance to learn the controls. Keep the game area visible while you use its controls.
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. Keep the objective visible.
Your goal
Create one connected sea around numbered islands of exactly the stated size, without a 2×2 sea block. Keep that objective in view throughout the round. Take a moment to understand the current position.
Step by step
- Shade sea squares and leave islands white.
- Every island contains exactly one clue.
- Different islands cannot meet along an edge.
- 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. Apply the same reasoning to the position in your own round. Consider the next action carefully.
Watch out for this
Two numbered islands may not merge into one. A different version of the game may use a different rule. Compare the worked example with your own position. Use the reasoning, not an answer copied from a different board.
Common questions
While reading the Guide, what is the goal of Nurikabe?
For clarity: Create one connected sea around numbered islands of exactly the stated size, without a 2×2 sea block.
When I return, how do I control Nurikabe?
Click or tap squares or graph edges. Number boards include a digit pad. Undo reverses the previous change; Check puzzle validates the solution.
When I return, what example helps explain Nurikabe?
The key detail is this: An island labelled 1 is already complete, so its edge neighbours must be sea.
When I return, what should I watch out for in Nurikabe?
The key detail is this: Two numbered islands may not merge into one.
For my first round, what format does Nurikabe offer?
Play ten compact 5×5 puzzles. Some boards begin with fixed shaded sea cells.
For a quick reminder, which play mode does Nurikabe use?
Here is the relevant explanation: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.