Reproduction Rate - True?

[CombatSquirrel]

I have been through the old threads and FAQs but could not seem to find the defineative answers all in one place.

I am focusing on reproduction rate here. Please correct the misconceptions I've gathered, and help fill in the blanks.

1) Reproduction rate is a percentage of current plantary population.
2) Planetary population increases by the reproduction rate per year(default), in whole units of population only. Fractions of population units are discarded and not carried forward.
3) "Reproduction Check Frequency" in Settings.txt adjusts the rate at which the Reproduction Rate is added to planetary population (default :=1 is once a year; :=2 is every other year; :=10 every 10 years).
4) The rate of reproduction is calculated and applied only on the turn that "Reproduction Check Frequency" calls for it to be applied. The rate at any other time before that turn is irrelevant.
5) "Empire Starting Percent Reproduction" (default :=10) in Settings.txt is the starting base reproduction rate, and all modifiers apply to this base.
6) All modifiers to "Empire Starting Percent Reproduction" are ADDED to this base, sequentially to finally acheive the reproduction rate.
7) The racial characteristic Reproduction adds or subtracts directly to the reproduction rate. Every point over 100 in this characteristic adds one point to the reproduction rate, every point under 100 subtracts one point.
8) The Happiness level of a planet's population also affects the reproduction rate. A Jubilant state adds 5 points to the reproduction rate, a Happy state adds 2 points, an Unhappy state subtracts 2 points, an Angry state subtracts 5 points.
9) A Rioting planet will always have 0% reproduction rate.
10) Climate (planetary conditions) also affects reproduction rate.
11) Conditions on each planet range from 1 (Deadly) to 100 (Optimal). At some midpoint range, there is no modifier on reproduction rate, but every 5 point increment above that range adds 1 point to reproduction rate for that planet. Every 5 point increment below that range subtracts 1 point from reproduction rate.
12) The racial characteristic Environmental Resistance affects the planetary conditions as perceived by the population. A race that has a 110% trait in Environmental Resistance will perceive a world with a planetary condition of 60 as if it were a 70. The effect of this is that each 5% of Environmental Resistance translates to a 1 point increase in reproduction rate, and -5% Environmental Resistance will be a 1 point decrease in reproduction.

This is all that I have been able to glean...

The question: is this true? Is there more?

CombatSquirrel

[Suicide Junkie]

3) "Reproduction Check Frequency" in Settings.txt adjusts the rate at which the Reproduction Rate is added to planetary population (default :=1 is once a year; :=2 is every other year; :=10 every 10 years).

Years are 10 turns long. default := 1 is 10 times per year, or every turn.

[Fyron]

2) Planetary population increases by the reproduction rate per year(default), in whole units of population only. Fractions of population units are discarded and not carried forward.

Fractions are rounded off, not discarded. Otherwise, a planet with 1 million population would never grow.

11) Conditions on each planet range from 1 (Deadly) to 100 (Optimal). At some midpoint range, there is no modifier on reproduction rate, but every 5 point increment above that range adds 1 point to reproduction rate for that planet. Every 5 point increment below that range subtracts 1 point from reproduction rate.

Actually, the conditions value ranges from 0.0 to 1.5. Deadly is from 0.0 to about 0.5 (or 0.6, I forget which). Optimal is like 1.4 or higher. Each class of conditions (Deadly, Harsh, Unpleasant, Mild, Good, Optimal) has a 2% difference in reproduction (except Optimal, which gets 1 extra point). With default rerproduction characteristics, you get this:
Optimal 17%
Good 14%
Mild 12%
Unpleasant 10%
Deadly 0%

Happiness levels also affect reproduction. The above levels are for a Happy population. Each lower level of happiness also lowers the reproduction rate by 2%. Jubliant, as Optimal, adds 3% instead of 2% to the Happy reproduction rate.

[ November 07, 2002, 22:06: Message edited by: Imperator Fyron ]

[Sinapus]

What seems to happen is that everytime the population check is done, it multiplies the current population by 1/10 of the population growth level and rounds fractions up. So everytime the population check runs, a planet will gain at least 1M population.

Changing the population check number (like to 10 in Proportions) will slow that growth down a bit. (Though personally, my own mod's current setting of 4 is painful enough.)

[dogscoff]

Encyclopedia Malfadorica - Population Growth

This is the EM's page on this subject. It's pretty comprehensive, but feel free to edit it if there is information here that is not listed in the EM.

[CombatSquirrel]

Thanks for the input... gave me enough to set up the tests.


(Corrected through experimentation. This I believe to be true and demonstratable.)

1) Population growth on each planet is determined by that planet's reproduction rate and how often the reproduction cycle is checked.

2) Every reproduction cycle, on every planet, each race of a planet's population increases by [current race population units * (Reproduction Rate/10)]. Fractions of whole units are rounded up to next whole unit.

3) "Reproduction Check Frequency" in Settings.txt adjusts the rate at which the population growth is added to planetary population (default :=1 is once a turn; :=2 is every other turn; :=10 every 10 turns (1 year)).

4) The Reproduction Rate is applied only on the turn that "Reproduction Check Frequency" specifies. The rate at any other time in the cycle is irrelevant. Population growth is calculated and added to planetary population immediately after an empire's turn, but before the next empire's turn begins.

5) "Empire Starting Percent Reproduction" (default :=10) in Settings.txt is the starting base reproduction rate for all empires and all planets. All modifiers are added to this base.

6) The Reproduction rate displayed with a planet is the current total of the Empire Starting Percentage Reproduction, racial characteristic modifiers, system modifiers and all modifiers for that individual planet. Any negative reproduction rate will always be displayed and treated as 0%.

7) The racial characteristic Reproduction adds or subtracts directly to the reproduction rate. Every point over 100 in this characteristic adds one point to the reproduction rate, every point under 100 subtracts one point.

8) The Happiness level of a planet's population also affects the reproduction rate. A Jubilant state adds 5 points to the reproduction rate, a Happy state adds 2 points, an Unhappy state subtracts 2 points, an Angry state subtracts 5 points.

9) A Rioting planet will always have 0% reproduction rate.

10) Climate (planetary conditions) also affects reproduction rate. Optimal (1.5) adds 5 points, Good (1.3-1.4) adds 2 points, Unpleasant (0.5-0.9) subtracts 2 points, Harsh (0.3-0.4) subtracts 5 points, and Deadly (0.0-0.2) subtracts 20 points.

11) Environmental Resistance has no effect on a population's perception of a planet's condition (Climate), nor any effect on happiness under any circumstance that I could detect. All that it does is grant a 1 point increase/decrease in reproduction rate for every 5 points that the Environmental Resistance characteristic is increased/decreased.


This is all that I have been able to glean...

The question: is this true? Is there more?

CombatSquirrel

[ November 08, 2002, 15:37: Message edited by: CombatSquirrel ]

[dogscoff]

Squirrel, that all looks true and correct to me. Please would you update the encyclopedia to include your findings? Just click the link in my previous post and hit "edit". If it asks you for a username just put in your name. There's no need for a password but usernames must have at least 2 capital letters in them.

If you can't be arsed to do all that, would it be OK for me to do so? It's just the kind of data the EM needs.

[ November 08, 2002, 16:24: Message edited by: dogscoff ]