Growth vat

The growth vat is a building added by the Biotech DLC. It allows the gestation and accelerated aging of babies and children.

Acquisition

Growth vats can be constructed once the Growth vats research project has been completed. Each requires 150 Steel, 4 Components and 8,000 ticks (2.22 mins) of work.

Summary

While hosting a human, growth vats require a constant 200W of power as well as nutrition. Both raw and processed foods, including nutrient paste, can be inserted.^[Hay?] None of the usual mood bonuses or maluses from different food types, such as from human meat, are applied. Hosting an embryo costs 6 nutrition per day and aging a child costs 3 nutrition per day. The vat's contents can be ejected immediately by the player by canceling vat growth; if it was an embryo, it will be destroyed. When no pawn is inside, the power consumption reduces to 80W

If the pod has no power or nutrition, the being inside will enter Biostarvation, increasing in severity by 50% per day starved, and decreasing 10% per day properly supplied. Biostarvation increases nutrition consumption in a vat by +10% at all severities, and kills at 100%. If a biostarved pawn escapes the vat, then hunger rate will be increased by +50%.

Baby creation

Growth vats be used to grow an embryo in 9 days, twice as fast as natural pregnancy, and regardless of either parent's Fertility (as long as it's above 0%). This comes without risk to the mother, but the baby can still arrive sick.

Growth vats have a birth quality of 70%. There is roughly an 89.1% chance for the baby to be born healthy.

Children

Colonists under 18 can also have their aging sped up by 20x, i.e., it takes 3 days to age 1 year. This ignores the default 4x aging multiplier for babies and children, so a vat is 5x faster than that. While in the vat, a pawn's needs are frozen like in cryptosleep, and children will not gain growth points. Every 3 days inside the vat, they will gain a small amount of skill, even if a baby.^[Rate?]

Non-psychopath parents (including surrogates) will have a −4 My child is in a growth vat moodlet while their kid is inside. This can be altered by ideoligion.

Biological Age	Time in vat
Biological Age	Base	Growth Vats: Essential
+1 Year	3 days	2.3 days
+3 Years	9 days	6.9 days
+5 Years	15 days	11.5 days
+18 Years	54 days	41.5 days

Ideology

Ideoligions can have an optional Growth Vats precept with two options:

"Growth vats: Essential" boosts grow vat speed by +30% (~6.9 days to grow an embryo, children grow 26x faster) and removes the mood penalty. It gives parents +2 mood for their own child in a vat.^[Verify] When expectations are moderate or higher, it gives parents a −2 Child not in growth vat mood for their child not being in a vat (stacking up to 3 times), pregnant pawns gain a −5 Natural pregnancy mood when pregnant, and all colonists gain a −3 No growth vats moodlet if the colony has no growth vats.^[Verify]
"Growth vats: Prohibited" gives negative mood for growth vats in your colony, and when any embryo or child is in a growth vat. The My child is in a growth vat increases to −8 (stacking 3 times, nullified by the psychopath trait), and gives a +1 Child not in growth vat mood for their child not being in a vat (stacking 3 times). All colonists gain a −3 Growth vat moodlet if the colony has a growth vat.

If neither precept is chosen, the ideoligion has no effect.

Analysis

If the Learning need is nonexistent, then growth vats will not negatively impact a pawn's development:

Babies (0-3) can be placed in the growth vat to speed up reaching toddler age. There are no apparent ill effects on the baby, and they even train an age-3 valid skill (Shooting, Melee, Social).
- However, parents who dislike growth vats gain the −4 moodlet, and it negates the mood buffs from having a happy baby in the colony.
If a child (3-13) is at growth tier 8, then no more growth points can be obtained, though children can learn from Work Watching or Lessons. Either way, the benefits are minor: these children will be a few days from growing up naturally.
Aging a teen (13-17) to 18 has no ill effect, and removes the body size and work penalties from being underaged. This costs up to 15 days of an almost-adult's time.

In these cases, vats exchange time for the cost of nutrition and power. Each vat doesn't consume much power, while nutrition can usually be solved by simply growing more food. For reference, an embryo is roughly equal to 4 colonists worth of food, consuming 60 simple meals over the 9 days. Growing a child is equal to 2 colonists.

On the other hand, fully vatgrown baseliners end up being fairly weak pawns. A vatgrown child will end up with 0 passions, very weak skills, and 3 random traits - a wanderer or just about any prisoner recruit is likely to just be better, without consuming nearly as much nutrition. Regardless, vatgrown children will ignore the game's natural population curve, and will always be able to fight, haul, and clean competently. Of these, hauling and cleaning can be accomplished with lifters and cleansweepers, both which are cheap and very early on the mechanitor progression path.

Nutrition

While raw food can be put into the dispenser, virtually any means of cooking a meal gives more nutrition per food item. The absolute best way to prepare food is the nutrient paste meal, which triples nutrition. However, colonists won't automatically dispense nutrient paste for a growth vat; they will only haul meals on the floor to it. See Nutrient paste#Manually producing meals for how you can stockpile nutrient paste.

Without nutrient paste researched, or if you don't want to micromanage everything, baby food is the next best way to prepare vegetables. Simple meals are the next best way to prepare other food items.

There are no penalties to anyone for using insect meat, already-butchered human meat, or other usually undesirable food items in a vat.

Version History

Biotech DLC Release - Introduced.