Reproduction

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Reproduction is the means by which human babies are created.

Note: Due to the continuous nature of the subject matter, this page covers from conception to the age of three.

Acquisition

Babies can be obtained via several different methods:

Note that with the exception of the last point, these methods become unavailable if "Disable children" is toggled on in the storyteller settings.

Natural

Pawns have a chance to get pregnant when they initiate lovin'. Note that pawns must share a two-person bed, bedroll, or sleeping spot to initate lovin' but do not require one to avoid the "sleeping alone" mood debuff.

Chance

The prospective parents' chance of successfully reproducing is primarily controlled by their Fertility stat. The player has three options to adjust pregnancy rates from Lovin' in any relationship. By opening the social tab, to the right of a Lover, Fiancee, or Spouse, you can see a button that lets you change the couple's strategy for having kids.

Normal.png Normal (Default) x1 pregnancy chance.
AvoidPregnancy.png Avoid pregnancy x0.25 pregnancy chance.
TryForBaby.png Try for baby x4 pregnancy chance.

Therefore, the total chance of pregnancy in one relationship is likely:

Pregnancy chance per relationship = Mother's fertility x Father's fertility x Baby strategy x Times Lovin'

The actual chance that a pair of pawns will do Lovin' each night varies, but it requires them to share the same bed and sleep at the same time. Their chance of Lovin' varies by age, as seen in this chart. The low libido and high libido genes will also alter this. There have been reports that colonist mood and opinions of each other also influence the chance of doing Lovin'.

Pregnancy

Pregnancy lasts for 18 days, broken into three 6 day trimesters. The pregnant pawn will gain penalties to movement, manipulation, and hunger rate, increasing each trimester as seen in the chart below.

Stage Effects
First trimester
  • Hunger rate offset: +10%
Second trimester
Third trimester

Throughout their pregnancy, they will also occasionally gain mood buffs or debuffs due to hormonal induced mood swings.[Detail needed] They may also receive the "morning sickness" condition, which lasts 4 to 8 ingame hours.

Morning sickness:

Note that Pawns in the character selection menu can begin the game already pregnant.

It is impossible for a mother that is lactating to have another child under any circumstances, even via surrogacy.

Birth

The player will recieve 1 notification when the mother hits the third trimester. Labor will happen roughly 6 days after,

Once labor begins, the birthing procedure can be initiated by clicking on the mother, and selecting the "Begin birth" option. This allows the player to select participants and a Doctor, much like Ideology's rituals. Presence of loved ones and a skilled doctor increase chance of a healthy birth. They will gather at a bed or equivalent. The quality of the procedure affects the probability that the baby will be born healthy, and can be improved by the presence of a skilled doctor and a loved one of the mother. The procedure will take place at a bed or sleeping spot, chosen automatically (preferring medical beds) if the player did not choose a bed themselves by starting the procedure via one.

The progress of labor can be tracked in the mother's health tab. Each successive stage of labor results in an increasing amount of pain, quickly incapacitating the pawn. Once birth is complete, the baby will appear on an adjacent tile, and the mother will be incapacitated by exhaustion for up to a full day. At this point, a pawn with the Childcare work enabled can be instructed to either move the baby to a safe space, or to deliver it to the mother for breastfeeding.

Outcomes

The baby can be born healthy, sickly, or die during birth. There is also a chance that the mother can die during childbirth. This is impacted by the quality of the room, the cleanliness, the quality of the bed, the quality of the doctor and if loved ones are around. The baby's first and last names can be changed within 1 game-day of birth, though nickname can always be changed.

If the baby is born sick, they are affected by a form of infant illness, which can start at a variable intensity. If left untreated before 10 days is up, the baby dies, but if it lives through 10 days after birth, the illness will no longer affect the baby.

Pawns that successfully give birth (regardless if healthy or sick) then lactate and can feed their child milk. After 10 days of not breastfeeding a child, they cease to lactate.

Assisted Reproductive Techniques

After Fertility Procedures has been researched, an ovum can be extracted from a fertile female pawn, be they colonist, prisoner, or slaveContent added by the Ideology DLC,. It may then fertilized by a fertile male colonist or slave (but not prisoner) to produce an embryo. The resulting embryo can then be implanted in female pawns (may be prisoner, colonist, or slave) to initiate a pregnancy, placed in a growth vat, or sold.

Surrogacy

With the Fertillity Procedures research, you can create and fertilize embryos. They can then be implanted into a pawn for a chance to become pregnant. The chance of success depends on the surrogate's own Fertility.

Embryos can be created from 2 pawns with any Fertility above 0%. Even if they did not supply the ovum, the surrogate will be considered the birth mother. Otherwise, it will act as a regular pregnancy.[Verify].

Growth vats

Growth vats are a complete alternative to pregnancy. They require the Growth vats research to make, as well as the Fertility procedures and 2 pawns with > 0% Fertility to actually create embryos.

They allow an embryo to be born in 9 days, half the time of a natural pregnancy. Active vats must be given a constant supply of 200 W of power and 6 nutrition per day - or around 6.5 simple meals - to ensure survival of the fetus. If lacking either, then the fetus will undergo biostarvation, increasing by 50% per day. If biostarvation reaches 100%, the fetus will be destroyed.

Growth vat births always have a quality of 70%, which affects the chance of the baby being born healthy. As it avoids natural birth, the mother won't be weighed down, and there is no risk of them dying. However, it also deprives pawns of the natural joys, or moodlets, of birth.

Heredity

When an embryo is conceived, it will inherit some of the genes of both parents.

Genes which can be passed down come from the germline DNA, and are called endogenes. Pawns may modify themselves with xenogenes, but as it's not part of a pawn's germline DNA, it cannot be passed down. If an endogene is only present in one parent, it has a small chance to be passed down.[What's the chance?] However if an endogene is present in both parents, it will always be passed down.

Generally, all pawns will have at least one hair color and skin color endogene. Offspring will always pick one hair color and skin color endogene from their parents. If no hair/skin color endogene can be found in either parent, such as if they were two highmates, a random hair/skin color endogene will be picked from the natural list of hair/skin colors instead.

If a pawn has multiple cosmetic genes within a category, like body type, one random gene will override the others. This will be the gene represented on the pawn. For non-cosmetic genes within a category there is a fixed priority for overrides, usually favored towards the negative variations. For example, an awful shooting aptitude will override all other shooting aptitudes. Xenogenes will always take priority over endogenes. Thus, even though the Slow runner endogene overrides their Fast runner endogene, the Fast runner xenogene will override the Slow runner endogene. Note that overridden endogenes can still be passed down as normal.

If a child is born from an incestuous relationship, there's a risk of them becoming inbred. [Verify]

Inbred

Gene Inbred.png

Fertility

Fertility is the main pawn stat and is a percentage multiplier on pregnancy chances. Pregnancy chance is dependent on the fertility of both partners. Fertility affects more than just the chance of a natural pregnancy, it affects all types of reproduction. It also affects the chance of successfully implanting an embryo in a surrogate, and sterility prevents both the extraction and fertilization of ova for IVF.

This stat is affected by a variety of factors, such as age and genes. For baseline humans without fertility-modifying genes, both men and women start becoming fertile after age 14; women's fertility increases until it reaches 100% through ages 20-28, then drops steadily from 100% to 0% at age 50, while men's fertility increases until it reaches 100% through ages 18-50, then starts dropping before reaching 0% at age 90. Fertility is also affected by contraceptives and genes. The Fertile gene doubles fertility and the Sterile gene completely nullifies it.

Regardless of fertility, a pawn must be at least 16 in order to participate in reproduction.

Female Fertility
Male Fertility

Contraceptives

The simplest way in the game to prevent pregnancy is to not give pawns a double bed to themselves. However, it deprives them of the mood bonuses of Lovin' in the first place. You can set pairs to avoid pregnancy in the Social tab, which reduces the rate by -75%. If a pawn is lactating (from having given birth before), then it is impossible for them to have a child under any circumstances.

The Fertility Procedures research gives access to multiple ways to stop pregnancy. These surgeries can be applied to any pawn age 16 and up, and can be performed even if the pawn is already infertile.

IUD

You can stop a female pawn from becoming pregnant with the "Implant IUD" operation. It lasts indefinitely, with the operation requiring Medicine 1 Medicine. You can later remove it through the "Remove IUD" medical operation, also for and Medicine 1 Medicine. Women may embark with IUDs already implanted. If either of these operations is botched, the patient will become permanently sterile.

IUDs also stop pregnancies in the first trimester.

Vasectomy

You can stop a male pawn from impregnating others with the "Perform vasectomy" operation. It lasts indefinitely, with the operation requiring Medicine 1 Medicine. You can later remove it through the "Reverse vasectomy" medical operation, also for and Medicine 1 Medicine. Men may embark with the operation already performed.[Verify] If either of these operations is botched, the patient will become permanently sterile.

Tubal Ligation

This permanently stops a female pawn from being able to reproduce. "Perform tubal ligation" is a medical operation requiring Medicine 1 Medicine of any type.

Termination

If the pawn has already become pregnant past the first trimester, the only option left is to terminate the pregnancy. This can be achieved through the medical operation "Terminate pregnancy" requiring Medicine 1 Medicine after which the pawn will no longer be pregnant. However, this will upset the affected pawn.[How much?]

Babies

The end result of pregnancy is a human baby. Babies are helpless creatures that cannot walk or do anything by themselves. They only have three basic needs: play, sleep, and food. Keeping the babies in the colony happy provided a decent mood boost for your colonies, by up to +8. The opposite is also true: crying babies can reduce mood by -8. Parents are less bothered by their baby crying, and happier when their baby is giggling.

Under the default storyteller settings, babies and other pawns under 18 will age 4x faster than normal. Growth vats can speed up a baby's growth by 20x an adult, or 5x faster than default. Using a growth vat seems to have no ill effects on a baby or its development, at least until it exits the baby stage.[Not thoroughly tested] However, parents gain a −4 moodlet.

Food

Babies have limited options when it comes to food. The easiest way to feed them is by having their mother or other lactating pawn breastfeed them. Another option is cook baby food from vegetable ingredients, or feeding them milk or insect jelly.

Sleep

Babies sleep in a crib when they are tired. Force-sleeping or feeding might wake them up, keeping them unhappy from being tired.

Play

Babies need to be played with, in place of standard Recreation. As long as there is a pawn with a high priority on child care, this will happen automatically once the needs bar is almost empty. There are differnt activities that will fulfill the baby's play need. A toy box and baby decoration increases the quality of play.

Giggling and crying

Babies can giggle and cry which gives a mood boost or penalty to other colonists up to (?) tiles away. The ratio between giggling and crying is directly related with the baby's mood.

Giggling occurance
Crying occurance
Giggling to crying ratio (higher is better)