Number Enclosure

Number Enclosure Game Introduction

Overview

Number Enclosure (also known as Kuromasu or Kurodoko) is a classic Japanese logic puzzle published by Nikoli. You are given a grid with some cells containing numbers. Your goal is to determine which cells should be shaded black, following strict logical rules about visibility and connectivity.

Rules

• Each number tells you how many white cells that cell can "see" along its row and column, including itself. Vision is blocked by black cells and grid edges.
• Numbered cells must remain white — they cannot be shaded black.
• No two black cells may be horizontally or vertically adjacent (diagonal is fine).
• All white (unshaded) cells must form a single connected group through horizontal/vertical adjacency.

Controls

• Left-click on an empty cell to cycle: White → Black → Dot (confirmed white) → White.
• Clicking a numbered cell does nothing (they are always white).
• Use Check to validate your solution.
• Use Hint for a logical deduction on the current board.
• Use Undo to revert your last move.
• Keyboard: H Hint, C Check, U Undo, N New Puzzle.

Scoring

The game tracks your time and number of moves. Fewer moves and faster times mean a cleaner solve. Use logic rather than trial and error for the best results.

Tips

• Start with small numbers (like 1 or 2) — they heavily constrain nearby cells.
• A cell with value 1 means all four neighboring cells in its row and column must be black.
• Large numbers in corners or edges are easier to analyze because they have fewer directions.
• Mark confirmed white cells with dots to track your progress.
• Remember: if shading a cell would disconnect white cells, it must stay white.
• Two adjacent empty cells where both being black would violate the adjacency rule — at least one must be white.

FAQ

What do the numbers mean? Each number shows the total count of white cells visible from that position in all four cardinal directions (up, down, left, right), including itself. Vision stops at black cells or grid edges.

Can two black cells touch diagonally? Yes, diagonal contact is allowed. Only horizontal and vertical adjacency is forbidden between black cells.

How many difficulty modes are there? There are 6 modes: 5×5, 7×7, and 10×10 grids, each with Easy and Hard variants. Larger grids and harder difficulties have fewer given numbers.