---
key: mechanic/puzzle--family-regions
type: mechanic
id: puzzle--family-regions
lang: en
title: 'Areas, Shading and Covering'
summary: >-
  The player defines region boundaries and contents according to local and
  board-wide rules.
updatedAt: '2026-10-22'
status: active
url: 'https://gamemechanics.pro/en/knowledge/mechanic/puzzle--family-regions/'
jsonUrl: >-
  https://gamemechanics.pro/api/v1/knowledge/en/mechanic/puzzle--family-regions.json
markdownUrl: >-
  https://gamemechanics.pro/content/knowledge/en/mechanic/puzzle--family-regions.md
aliases:
  - 'Regions, coloring and coverage'
tags:
  - Puzzles
  - Mechanics catalog
sourceIds:
  - source-da82112b200ad8e7
  - source-466a432ae29a0419
  - source-525fd3968ac77ef5
  - source-a540e363dfa26525
  - source-e0f9d3460012faaa
sources:
  - id: source-da82112b200ad8e7
    title: 'Nikoli: Shikaku'
    url: 'https://www.nikoli.co.jp/en/puzzles/shikaku/'
    verifiedAt: null
  - id: source-466a432ae29a0419
    title: 'Nikoli: Fillomino'
    url: 'https://www.nikoli.co.jp/en/puzzles/fillomino/'
    verifiedAt: null
  - id: source-525fd3968ac77ef5
    title: 'Nikoli: Nurikabe'
    url: 'https://www.nikoli.co.jp/en/puzzles/nurikabe/'
    verifiedAt: null
  - id: source-a540e363dfa26525
    title: 'Nikoli: Hitori'
    url: 'https://www.nikoli.co.jp/en/puzzles/hitori/'
    verifiedAt: null
  - id: source-e0f9d3460012faaa
    title: Dorfromantik
    url: 'https://store.steampowered.com/app/1455840/'
    verifiedAt: null
relations: []
placements:
  - catalogId: puzzle
    id: family-regions
    title: Puzzles
    url: 'https://gamemechanics.pro/en/mechanics/puzzle/#family-regions'
    categoryIds:
      - section-1
supersededBy: []
attributes:
  preview:
    updatedAt: '2026-10-22'
    title: 'Regions, coloring and coverage'
    description: >-
      The player defines region boundaries and contents according to local and
      board-wide rules.
    image:
      src: images/mechanics/adventure-dorfromantik-00.webp
      width: 1440
      height: 810
      game: Dorfromantik
      sourceUrl: 'https://store.steampowered.com/app/1455840/'
      originalUrl: >-
        https://shared.akamai.steamstatic.com/store_item_assets/steam/apps/1455840/ss_a49e5fcc5301e8a05a1da7ce233a5377cf680e98.1920x1080.jpg?t=1786951108
      credit: Toukana Interactive
      rights: >-
        Game imagery © its respective rights holders. Publisher-distributed
        Steam screenshot; all rights reserved. Excluded from MIT and CC BY 4.0.
      caption: 'Adjacent tiles combine forests, water and settlements'
      alt: 'Adjacent tiles combine forests, water and settlements'
      markers:
        - x: 38
          'y': 42
          label: Connected region of one terrain type
        - x: 25
          'y': 73
          label: Boundary of the available coverage
    tips:
      - Show region boundaries and completion conditions.
    examples:
      - title: Dorfromantik
        url: 'https://store.steampowered.com/app/1455840/'
endsAt: null
provenance: >-
  Original editorial design catalog consolidated from project discussions on
  2026-10-20. Complete discussion item lists and contextual limitations are
  preserved; linked primary sources support specific techniques, not the entire
  classification. English translation was prepared with machine assistance and
  editorial review.
license: CC-BY-4.0
codeLicense: MIT
attribution: gamemechanics.pro contributors
catalogKey: catalog/puzzle
---
# Areas, Shading and Covering

id: puzzle--family-regions
type: mechanic
key: mechanic/puzzle--family-regions
lang: en
status: active
url: https://gamemechanics.pro/en/knowledge/mechanic/puzzle--family-regions/

The player defines region boundaries and contents according to local and board-wide rules.

## At a glance

![Adjacent tiles combine forests, water and settlements](https://gamemechanics.pro/images/mechanics/adventure-dorfromantik-00.webp)

[Dorfromantik](https://store.steampowered.com/app/1455840/) · Game imagery © its respective rights holders. Publisher-distributed Steam screenshot; all rights reserved. Excluded from MIT and CC BY 4.0.

1. Connected region of one terrain type
2. Boundary of the available coverage

- Show region boundaries and completion conditions.

- [Dorfromantik](https://store.steampowered.com/app/1455840/)

## How it works

Determine the boundaries and composition of areas according to local and global rules.

## Variants

### Variants and applications

<a id="family-regions-variants"></a>

- Partition into rectangles. Definition: Divide the field into rectangular areas of a given area. Conventional example: Surround the number 6 with a rectangle of six cells. Terms: Shikaku. <a id="variant-rectangular-regions"></a>
- Areas of a given size. Definition: Divide the grid into connected groups, the size of which is determined by the value. Conditional example: Collect an area of ​​five fives. Terms: Fillomino. <a id="variant-size-regions"></a>
- Islands and the common sea. Definition: Select islands of the required size and a coherent surrounding area. Conventional example: Separate numerical islands by a continuous sea. Terms: Nurikabe. <a id="variant-islands-sea"></a>
- Symmetrical areas. Definition: Divide the field into regions with given centers or axes of symmetry. Conditional example: Construct rotationally symmetric “galaxies”. Terms: Galaxies; Tentai Show. <a id="variant-symmetric-regions"></a>
- Quotas within regions. Definition: Distribute marks among rooms with given quantities and neighborhood restrictions. Conditional example: Paint exactly two cells in each room. <a id="variant-region-quota"></a>
- Removing repetitions by painting. Definition: Eliminate repetitions while maintaining the connectivity of the remaining cells and the admissible proximity. Conditional example: Color over extra numbers in the lines. Terms: Hitori. <a id="variant-duplicate-shading"></a>
- Continuous painting. Definition: Select cells so that the selected color forms one connected structure. Conditional example: Connect all black fragments without forbidden squares. <a id="variant-connected-shading"></a>
- Coloring of neighboring areas. Definition: Assign colors so that neighboring areas satisfy constraints. Conventional example: Color a map with a limited palette. Terms: graph coloring. <a id="variant-region-coloring"></a>
- Shading according to viewing range. Definition: Block lines of sight so that the required number of cells are visible from the marks. Conditional example: Limit the view of numerical observers. Terms: Kurodoko; Kuromasu. <a id="variant-visibility-shading"></a>
- Filling with the capture of neighbors. Definition: Change the color of a connected area, absorbing neighboring groups. Conditional example: Combine the entire field in several recolors. Terms: Flood-It. <a id="variant-flood-fill"></a>

## Context and limits

A wide catalog of mechanics for digital puzzles, paper logic problems and physical puzzles. Each position contains an action or rule and a conditional example of application.

## Connected materials


## Sources and provenance

Original editorial design catalog consolidated from project discussions on 2026-10-20. Complete discussion item lists and contextual limitations are preserved; linked primary sources support specific techniques, not the entire classification. English translation was prepared with machine assistance and editorial review.

- [Nikoli: Shikaku](https://www.nikoli.co.jp/en/puzzles/shikaku/) (id: source-da82112b200ad8e7)
- [Nikoli: Fillomino](https://www.nikoli.co.jp/en/puzzles/fillomino/) (id: source-466a432ae29a0419)
- [Nikoli: Nurikabe](https://www.nikoli.co.jp/en/puzzles/nurikabe/) (id: source-525fd3968ac77ef5)
- [Nikoli: Hitori](https://www.nikoli.co.jp/en/puzzles/hitori/) (id: source-a540e363dfa26525)
- [Dorfromantik](https://store.steampowered.com/app/1455840/) (id: source-e0f9d3460012faaa)

CC-BY-4.0 · gamemechanics.pro contributors