Guide:Population Management

Overview

Population Management refers to the methods of increasing or decreasing the overall number of sapiens in your tribe. This guide outlines the mechanics in the game that allow some level of control over how large or small your population is, as well as advanced control through the configuration file.

Increasing Tribe Population

The following describes net positive population mechanics in the game that will increase your tribe population.

Pregnancy and Births

A pregnant female Sapien

Sapiens are able to mate and give birth to children. Within the game, there is a periodic check to see if a pregnancy will occur based on a set of rules. This process is influenced by both in-game conditions and settings in the `config.lua` file, which can limit birth rates as populations grow.

Rules for Pregnancy

The game evaluates potential mothers and fathers based on specific criteria:

Rules for the Female

1. The Sapien must be female.
2. The female must not already be pregnant or have a baby.
3. The female cannot be a nomad.
4. The female must be an adult, but not an elder.
5. The female must be young enough that the pregnancy will not extend until they become an elder (younger than 52).
6. The female's loyalty mood must be at least Mildly Negative (3 Stars) or higher.
7. The female must not be very hungry (food desire < strong).
8. The tribe must have at least 5 food units in storage.
9. The tribe must allow population growth (controlled by game settings or `config.lua`).

Rules for the Male

Once a female Sapien meets the above criteria, the game checks for a suitable father:

1. The Sapien must be male.
2. The male must be an adult or elder (15 years or older).
3. The male must not have a close family relationship with the female (e.g., not a parent, sibling, or child).
4. The male must have a sufficient relationship score with the female (short-term bond + mood based on recent interactions within the last 5 minutes).
5. The male must have been seen recently by the female.

Pregnancy Check Process

If both female and male criteria are met, the game evaluates additional conditions:

• Food Availability: The tribe’s food storage is assessed. A food count fraction (food units divided by tribe population + 1, clamped between 0 and 1) influences the pregnancy delay timer.
• Population Limits: Birth rates are suppressed based on tribe and global population soft caps set in `config.lua`. For the tribe, suppression starts at 80% of the `populationLimitPerTribeSoftCap` (default 200) and fully prevents births at 120%. Globally, suppression starts at 80% of `populationLimitGlobalSoftCap` (default 500) and fully prevents births at 120% for all player tribes.
• Timer: A pregnancy delay timer (`pregnancyOrBabyTimer`) accumulates based on food availability and population suppression. It must reach 1.0 (default 5 game days, adjusted by food and population factors) for a pregnancy to occur.

If all conditions are met, the female becomes pregnant, and the father contributes genes for skin color, hair color, and eye color to determine the baby’s characteristics. The pregnancy lasts approximately 20 game days, after which a baby is born. The baby remains with the mother for about 40 game days before becoming a child Sapien.

Tips for Maximizing Pregnancy Chances

Births alone are not sufficient to significantly increase population due to their slow rate and dependency on population caps. Without nomadic recruitment, the population may decline over time. To maximize pregnancies:

1. Pair young female and male couples by assigning them adjacent beds to improve their relationship scores through proximity during idle time.
2. Reduce workloads for planned pairs to increase idle time together.
3. Maintain high mood levels with musicians and ensure food needs are met (food desire < strong).
4. Ensure at least 5 food units are in storage to avoid blocking pregnancy checks.
5. Adjust `config.lua` settings to increase `populationLimitPerTribeSoftCap` or `populationLimitGlobalSoftCap` if birth rates are too low due to population suppression (see Managing Population via Configuration File).

Nomadic Tribe Recruitment

A tribe of 3 nomads approaching a Sapien settlement.

Notification when nomads join the player's tribe.

Recruiting wandering nomadic tribes is the fastest way to increase your tribe’s population, as large groups can sometimes join at once.

Once a nomadic tribe is spotted, engage them by pressing the Enter key while the notification is active in the top right corner. Pause the game, select a nomad, and choose "Recruit" from the radial menu. A Sapien with the Diplomacy skill will attempt to recruit the nomad, and if successful, the entire nomadic tribe joins.

Rules for Nomadic Tribe Spawning

Every 0.5 to 1.5 game days, the game attempts to spawn a nomadic tribe 300m from your Sapiens. The spawn fails if:

• Water is between the spawn point and your Sapiens.
• The spawn point is not at least 280m from a Sapien.
• Specific conditions for the tribe’s intention are not met (e.g., food storage requirements).

Nomadic tribes have different intentions, affecting their behavior:

1. Food Raid: Targets a storage area with at least 5 food. (Spawn fails without valid food storage.)
2. Friendly Visit: Heads toward a Campfire or nearby position.
3. Join: Heads toward a Campfire. (Spawn fails if average tribe mood is very negative or no food storage has at least 10 food.)
4. Cautious Visit: Heads toward a Campfire or nearby position.
5. Just Passing Through: Walks through your village.
6. Leave: Walks away and despawns.

Maximizing Nomad Recruitment

To increase recruitment success:

1. Avoid settling near rivers or coasts, as water reduces spawn chances. Small islands may prevent spawns entirely.
2. Assign adults (not elders) to the Diplomacy role, as elders are slower and may fail to reach nomads in time.
3. Ensure diplomats are not pregnant or mourning, as this slows them down.
4. Clear other tasks for diplomats to ensure prompt recruitment attempts.
5. Maintain a food storage with at least 10 food units and an average tribe mood of at least Moderately Negative to enable "Join" spawns.
6. Re-recruit Sapiens who left due to low loyalty (0), but address the underlying issues quickly to prevent repeated departures.

Decreasing Tribe Population

The following describes net negative population mechanics that reduce the number of sapiens in your tribe. Setting a low `populationLimitPerTribeSoftCap` in the `config.lua` file can also limit births, effectively capping population growth (see Managing Population via Configuration File).

Old Age

Sapiens age through life stages (child, adult, elder). Elders eventually die of old age (65 Years), reducing the tribe’s population. Notifications are sent when a Sapien dies, and friends or family may experience mood penalties.

Disease and Injury

Sapiens can contract viruses or sustain injuries (minor, major, or critical), which may lead to death if untreated. Viruses spread among close Sapiens, and injuries occur randomly through various tasks (ie. Wood Cutting). Burns can also be fatal. Please note the likelihood that a sapien dies from an untreated medical ailment is low, and will most likely result in part of your workforce be out of commission for an extended time before they heal naturally.

Leaving the Tribe and Exiling Tribe Members

Sapiens with severe negative loyalty (below Mildly Negative) may leave the tribe after a 1440-second timer (approximately 1 game day).

Managing Population via Configuration File

In addition to in-game mechanics, you can control your tribe’s population by modifying the `config.lua` file in your world’s save folder. This file allows you to set soft caps on population growth, influencing birth rates to manage tribe size and game performance. Access it via the "Saves" menu by clicking on the "Files Location -->" button.

Steps to Configure Population Limits

1. Locate the `config.lua` File: Find it in your world’s save folder.

2. Edit the File: Open `config.lua` in a text editor. Look for two commented-out (--) parameters:

  -- populationLimitGlobalSoftCap: Sets a global limit for all player-controlled tribes in multiplayer or server settings.
  -- populationLimitPerTribeSoftCap: Sets a limit for your specific tribe.

3. Uncomment and Set Values: PLEASE NOTE! Any line in the file that begins with '--' are ignored. To change a setting, you must delete the two '-' characters from the start of the line, otherwise it will be ignored and overwritten with the default. The edited lines should look like this without '--' at the beginning of the lines:

  populationLimitGlobalSoftCap = 500, --As the global population of player-controlled loaded sapiens gets closer to this level, birth rate decreases globally
  populationLimitPerTribeSoftCap = 50, --For a player-controlled tribe, birth rate reduces until at around this level the population won't grow any further

4. Save and Reload: Save the file and reload your game for changes to take effect.

How Population Limits Work

The `config.lua` settings introduce a suppression mechanism for birth rates based on population size:

• Global Soft Cap: When the total population of player-controlled Sapiens nears `populationLimitGlobalSoftCap` (default 500), birth rates decrease globally. Suppression starts at 80% of the cap (e.g., 400) and fully prevents births at 120% (e.g., 600). This helps manage server performance in multiplayer.
• Per-Tribe Soft Cap: When your tribe’s population approaches `populationLimitPerTribeSoftCap` (default 200), its birth rate slows. Suppression begins at 80% (e.g., 160) and stops growth at 120% (e.g., 240). This stabilizes your tribe’s size.
• Suppression Mechanism: The game calculates a suppression fraction based on how close the population is to these caps. This fraction reduces the `pregnancyOrBabyTimer` progression, delaying or preventing pregnancies. For example, at 100% of the cap, the timer slows significantly, and at 120%, it effectively halts.
• Performance Impact: Higher populations can cause lag on weaker hardware. Adjust caps to balance growth and performance.

Tips for Effective Use

• Balance Growth and Performance: Use conservative caps (e.g., 300 global, 100 per tribe) to prevent lag. Increase them if your hardware can handle larger populations.
• Monitor Birth Rates: Check pregnancy notifications to gauge if caps are too restrictive. Adjust `populationLimitPerTribeSoftCap` upward if births are rare.
• Test Adjustments: Experiment with values and reload the game to find optimal settings for your playstyle and hardware.
• Combine with In-Game Mechanics: Use `config.lua` settings alongside pregnancy optimization and nomadic recruitment for precise population control.