Silo (2023) is a great series; it is set in a seemingly post-apocalyptic world in which 10,000 people live in a ‘silo’ or underground vault. The silo is entirely self-sustaining, across its 144 floors everything is covered, from food to electricity production, to maintenance, medical care, and security, to anything else you can think of, anything which would be necessary to keep the population self-sustained. Through carefully monitoring and sanctioning of childbearing this 10,000-population number is kept static.

This got me thinking about how difficult it would be to maintain a stable population within a closed system. As we can see from population statistics, childbearing from one generation to the next is not at all stable. In the United States, women are having on average 1.62 children; this number has halved since the early 1960s. The replacement rate is 2.1; that is the number to replace the father and the mother, with the .1 accounting for child mortality, women who cannot reproduce, or women who die before they do so. As such, if a woman has fewer than 2.1 children, they are contributing to population decline.

If we assume life expectancy is 77 (I’m not sure if in an underground vault in which everyone’s needs are accommodated for, we should assume a lower or higher life expectancy than the current national average). I’m also assuming no individual autonomy; this would all have to be managed planned-economy style. I’m also assuming that all childbearing is done by women aged 20 to 30—if you’re going to manage this directly, it’s probably best to target the optimal fertility window.

So, the calculation would be 10,000 / 2 = 5000 women. 5000 women / 77 ≈ 65 women per age group. 65 * the 10 optimal fertility years = 650 women at any given time aimiing to have their approximate 2.1 children within their fertility window. In such a limited system, maintaining a stable population is not as simple as meeting replacement rates, however. Genetic variability must also be carefully managed to avoid inbreeding and ensure long-term viability. Additionally, a static system of this size would be highly susceptible to the effects of sudden mortality events, such as disease or disasters. These risks make it imperative to regularly monitor and modulate the population at a granular level.

This would be a good idea for a computer game. Many games are based on exploration, base building, and resource exploitation, but what about a game in which all of that is already done, and the objective is just to maintain the population, optimize for genetic traits, educate and deploy individuals to work within a closed system of this kind.

Game Design Document

Vaultborne: A Matchmaker’s Dilemma
In Vaultborne, you take on the role of population manager for an isolated colony of 10,000 individuals living in a self-contained underground vault. Built to preserve humanity after a global catastrophe, the vault is a sealed, self-sustaining ecosystem where every resource and individual must be carefully managed to ensure survival.

Through strategic matchmaking, education programs, and job allocation, you must maintain genetic diversity, balance labor needs, and preserve the vault’s long-term viability. The simulation evolves dynamically, presenting challenges like resource scarcity, genetic drift, and cultural conflicts, ensuring every decision has far-reaching consequences.

Core Gameplay

1. Matchmaking
   • Pair individuals for reproduction to optimize genetic diversity and enhance desirable traits.
   • Manage risks like inbreeding and genetic stagnation while responding to mutations or disease outbreaks.
   • Balance societal preferences, such as prioritizing strength, creativity, or discipline, based on the vault’s needs.
2. Education
   • Design and manage educational programs to train individuals for critical roles, such as engineers, doctors, and farmers.
   • Choose between broad-based education (generalists) or specialized training (experts) to address immediate and future needs.
   • Shape cultural values, emphasizing traits like innovation or obedience.
3. Labor Management
   • Assign individuals to jobs across sectors like agriculture, energy, medicine, security, and governance.
   • Reassign workers during crises, balancing efficiency with morale and long-term consequences.
4. Morale and Culture
   • Make decisions that influence cultural trends, like valuing collectivism over individualism or creativity over discipline.
   • Maintain morale through fair policies, festivals, and cultural initiatives—or risk rebellion and productivity loss.

Setting and Themes

Setting:
A sealed underground vault designed for long-term human survival. Limited resources, environmental maintenance, and psychological challenges define the colony’s existence.

Themes:

• Survival: Navigate the balance between short-term needs and generational stability.
• Ethics: Make tough decisions about individuals vs. the collective good.
• Legacy: Shape the genetic and cultural future of humanity.

Dynamic Events

• Genetic Crises: Disease outbreaks or harmful mutations threaten the vault’s survival.
• Resource Failures: Systems break down, requiring creative problem-solving.
• Cultural Conflicts: Competing ideologies within the vault create social unrest.
• Ethical Dilemmas: Choose between sacrificing individuals or jeopardizing the population.

Key Features

• Dynamic Population Simulation: Every individual has unique genetic and cultural traits. Generational growth is directly affected by your matchmaking and educational decisions.
• Indirect Control: Use policy sliders and targeted actions to influence the vault without direct micromanagement.
• Long-Term Strategy: Plan for generations while addressing immediate crises.
• Emergent Narratives: Follow influential families or key individuals as their traits and ideologies shape the vault.

Art and Sound Direction

Visual Style:

• A clean, data-driven interface complemented by isometric views of the vault.
• Detailed family trees and individual portraits highlight generational evolution.

Sound:

• Ambient soundscapes (e.g., machinery, distant chatter) create an immersive environment.
• Adaptive music shifts with the vault’s morale or major events.

Target Audience

• Fans of management sims like Oxygen Not Included, Frostpunk, or Surviving Mars.
• Players who enjoy generational strategy games like Crusader Kings.
• Gamers drawn to ethical dilemmas and long-term planning.