We know that population growth is so massive as to always put us at the 200M population growth cap, thereby rendering population growth racial bonuses meaningless. Using scenarios, I did some playing around with the "PopulationGrowth" variable to try and determine the mechanics of population growth and make the game a bit more realistic. The following info can be used by players to edit scenarios for themselves, and will hopefully be considered as a way to rebalance the population growth values.

As far as I can tell, the actual growth mechanics are fine, but the values are totally out of whack. The default setting for "PopulationGrowth" is 50. By creating a scenario and editing the value, then testing in game, I determined that a setting of 50 seems to represent 100% population growth, though this is further modified by planetary happiness to be a smaller percentage somewhere in the range of 50% to 80% actual growth. To get 0% population growth, you actually have to set the "PopulationGrowth" value to -50. A setting of lower than -50, and population will actually shrink on happy planets.

I've played a scenario with a -40 "PopulationGrowth" value, and one with a -44 value, which corresponds to 10% and 6% base growth. I modified the racial population special ability to add 2%, 4%, 6%, and 14% instead of the 10% to 70% default. I also modified Aphrodisiac to give a 10% bonus instead of a 50% bonus. Some of the "event" modifications might have to be considered as well -- there was one event in my "-44" game that put one of my planets at -2% population growth.

The net effect of these changes were significantly slower colony growth, and a weaker early economic base. I enjoy this style of play, though it is probably not for everyone. Eventually the colonies will get to the point where growth is at the 200 cap, but it takes a looong time to get there. Racial bonuses to population growth are very visible as long as there is room on the planet for expansion. For example, the Torian took a clear population lead in both games with their racial bonus (modified to 6% from 30% default).

Here are the ways that gameplay was affected:

1) Population must be considered when loading colony ships. If you send out 100M, the colonies will grow very very slowly. Ferrying population from populated to underpopulated worlds will be desirable in some situations.

2) Lower population growth across your colonies means you have to carefully balance your manufacturing / research capacity with your economic base. It is really easy to overbuild capacity.

3) Racial growth bonuses are meaningful.

4) Small colonies (less than 4-5 should be used sparingly for loading up troop transports.

5) Invaded worlds actually take a while to recover their population. (Don't you hate it when an invasion fails and the world completely recovers its population.)

6) Planetary happiness has a significant impact on growth during the early stages of the game.


I think this model would work for people who want a slower paced game with a more realistic population growth rate. There is more strategy involved in planning out your empire. It DOES slow down the early part of the game a bit. I'm not sure what was originally intended for population growth, but the static 200 growth is not real interesting. I do think the cap is useful for big planets, but it is just silly that small colonies hyper-explode to 5B in about 25 turns.

Hopefully this has been helpful to anyone who wants to play with custom scenarios in ..\GalCiv2\Data\English\Scenarios

Just remember, you have to take it upon yourself to try and balance out some of the other population modifiers in the game -- weird things might happen -- this was just a proof of concept experiment I was doing until I get more info on how to properly modify the game. These changes are not hard to make for anyone who was already inclined to examine and tweak the xml data. The rest should wait for the official mod guide -- please don't mess up your installed game.