---
key: mechanic/tactics-defense--t085
type: mechanic
id: tactics-defense--t085
lang: en
title: 'Base defense, sieges and waves'
summary: >-
  Waves test a base's resilience while preparation and repair split limited
  resources between current and future threats.
updatedAt: '2026-10-22'
status: active
url: 'https://gamemechanics.pro/en/knowledge/mechanic/tactics-defense--t085/'
jsonUrl: >-
  https://gamemechanics.pro/api/v1/knowledge/en/mechanic/tactics-defense--t085.json
markdownUrl: >-
  https://gamemechanics.pro/content/knowledge/en/mechanic/tactics-defense--t085.md
aliases: []
tags:
  - Tactics and defense
  - Mechanics and variants
sourceIds:
  - source-32d0598945d8807a
  - source-950c2d068141427b
sources:
  - id: source-32d0598945d8807a
    title: OpenRA
    url: 'https://www.openra.net/'
    verifiedAt: null
  - id: source-950c2d068141427b
    title: They Are Billions
    url: 'https://store.steampowered.com/app/644930/'
    verifiedAt: null
relations: []
placements:
  - catalogId: tactics-defense
    id: t085
    title: Tactics and defense
    url: 'https://gamemechanics.pro/en/mechanics/tactics-defense/#t085'
    categoryIds:
      - mechanics
supersededBy: []
attributes:
  preview:
    updatedAt: '2026-10-22'
    title: 'Base defense, sieges and waves'
    description: >-
      Waves test a base's resilience while preparation and repair split limited
      resources between current and future threats.
    image:
      src: images/mechanics/strategy-they-billions-08.webp
      width: 1440
      height: 810
      game: They Are Billions
      sourceUrl: 'https://store.steampowered.com/app/644930/'
      originalUrl: >-
        https://shared.akamai.steamstatic.com/store_item_assets/steam/apps/644930/ss_4c32c120efcf58bac44ae8316f22a1b2a722185f.1920x1080.jpg?t=1595631876
      credit: Numantian Games / Numantian Games
      rights: © Numantian Games / Numantian Games. All rights reserved.
      caption: A mass of infected attacks the outer perimeter
      alt: A mass of infected attacks the outer perimeter
      markers:
        - x: 27
          'y': 40
          label: Walls hold back the advancing crowd
        - x: 64
          'y': 64
          label: Base structures stand behind the defensive line
    tips:
      - >-
        Allow recovery time between waves and expose weak points in the
        perimeter.
    examples:
      - title: They Are Billions
        url: 'https://store.steampowered.com/app/644930/'
endsAt: null
provenance: >-
  Original bilingual editorial overviews authored for gamemechanics.pro on
  2026-10-20 and reviewed on 2026-10-21. Scenarios are hypothetical design
  examples; prototype checks describe work to perform, not completed playtests.
  Primary sources support the stated techniques and implementation context, not
  every proposed variant.
license: CC-BY-4.0
codeLicense: MIT
attribution: gamemechanics.pro contributors
catalogKey: catalog/tactics-defense
---
# Base defense, sieges and waves

id: tactics-defense--t085
type: mechanic
key: mechanic/tactics-defense--t085
lang: en
status: active
url: https://gamemechanics.pro/en/knowledge/mechanic/tactics-defense--t085/

Waves test a base's resilience while preparation and repair split limited resources between current and future threats.

## At a glance

![A mass of infected attacks the outer perimeter](https://gamemechanics.pro/images/mechanics/strategy-they-billions-08.webp)

[They Are Billions](https://store.steampowered.com/app/644930/) · © Numantian Games / Numantian Games. All rights reserved.

1. Walls hold back the advancing crowd
2. Base structures stand behind the defensive line

- Allow recovery time between waves and expose weak points in the perimeter.

- [They Are Billions](https://store.steampowered.com/app/644930/)

## How it works

Waves test a base's resilience while preparation and repair split limited resources between current and future threats.

## Variants

### Mechanic variants

<a id="t085-variants"></a>

- Wave scouting reveals the upcoming composition. <a id="t085-v1"></a>
- Repairs compete with buying additional defenses. <a id="t085-v2"></a>
- Sieges attack specific structural weaknesses. <a id="t085-v3"></a>
- Respite allows relocating defensive equipment. <a id="t085-v4"></a>

## Design example

After an aerial wave, the player repairs a roof and postpones strengthening the ground gate.

Prototype check: Test recovery after a hard wave so a surviving base is not inevitably lost without further decisions.

## Context and limits

Tactics and defense turn positioning, action order and preparation into limited resources. Each overview separates player actions, state changes and alternative rules. Examples are hypothetical design scenarios, not claims about a named game. A prototype check states an observable question for the next iteration. Existing detailed references remain separately linked from the direction map.

## Connected materials


## Sources and provenance

Original bilingual editorial overviews authored for gamemechanics.pro on 2026-10-20 and reviewed on 2026-10-21. Scenarios are hypothetical design examples; prototype checks describe work to perform, not completed playtests. Primary sources support the stated techniques and implementation context, not every proposed variant.

- [OpenRA](https://www.openra.net/) (id: source-32d0598945d8807a)
- [They Are Billions](https://store.steampowered.com/app/644930/) (id: source-950c2d068141427b)

CC-BY-4.0 · gamemechanics.pro contributors