A Conversation About Population Size

[tman2000]

I've been working on a mod that makes the town-city ecosystem work better IMO, part of which involves having more towns and making cities harder to get. The first step in this process has been to increase growth rates, so that growth is actually sensitive to food and food buildings actually trade-off with other building types. The result has been a Civ III style of play with 20 towns in antiquity that get to 12-20 in size with a couple 30 sized cities. If you play it on the modded map that was one size bigger than what's available in vanilla, it's perfect. It feels really good.

The problem is, it inherently breaks the exploration and modern ages. This speaks to the design flaw behind the age system, which is meant to prevent snowballing, but snowballing in the expansionist Civ III style is fun. Of course V dialed that back for a tall style, but I genuinely believe that having a difference between towns and cities renders the tall v wide debate moot. The game should be calibrated for Civ III style wide, but trading off with investment into cities if tall is preferred. I also think this means cities need to go a lot taller, with 5 tile radius and without the nerfed growth rates. Where setting up farming towns can actually skyrocket city growth, and with other town specializations that are very good and painful to trade off from in order to grow cities. That's the balance that seems right, at least philosophically.

What hinders growth, so that "food doesn't matter" is the game's age calibration where food actually does finally matter in the modern age. In order to prevent snowballing, they have to calibrate it so that food cannot matter until the end. This means the 4th age is already broken since food "takes off" in the modern age. Then, they have to tighten up growth and make food worthless in antiquity. This is so settlements which reach growth limits of a given age can then keep growing even bigger in the next age. You can see this with the overbuilding in terms of the art direction, where each age's buildings are a bit taller than previous ages so they stand out. I like that art decision, but I disagree with the mathematics.

Here's a question: do settlements need to be larger as ages progress?

Rome was 1-2 million people. Antioch 500,000, Alexandria 200,000. Medieval Baghdad was 900,000. Paris was 700,000. Chinese capitals were pretty consistently around 1 million. Edo Japan was 1 million. Paris didn't reach 1 million until 1850 and never got past 2 million.

In the modern era (up to 1950), you start to get 2+ million up to around 10 million. Obviously there are monster cities 20-40 million today.

Maybe population should shrink in the exploration/antiquity age transition?

There are other nuances. Rome was so large because it was fed by hundreds of farming settlements. That's sort of in the game, although the tight growth rates nullify that. If Rome was 1-2 million, that's modern Paris. So if a Modern Age city will get to 35-45 pop, then that means Rome in antiquity, if you max out farming towns, should get to around 40 in size. See what I mean? The current growth curves don't support that.

On the other hand, medieval populations were much larger than antiquity because of things like the steel plow. However, the population was distributed.

Here are some takeaways from this information:

• City growth rates should not be nerfed in antiquity relative to modern. Growth should be sensitive to food in Antiquity as it is in Modern
• Maybe Antiquity towns need population caps, but removing or lightening settlement caps for towns.
• In Exploration, town population caps will be raised, representing a critical difference.
• In Modern, not much has changed except there are much better food buildings.

I also don't get ageless warehouses. It feels like there was intent there to create a foundation of how settlements produce yields, with an early baseline scaling premise, but I'm not sure it works anymore and people hate the ageless buildings. I should have an antiquity powered granary I'm desperate to build over with a gristmill. In Modern I should have massive industrial grain silos, maybe two tiers, that boost farm productivity. It should always have been more food that makes later ages grow better, not modified growth rates.

The problem is, when you're talking about tight maps and balanced game for online play, you just can't have that much growth. But this is 4X, this is Civilization. There should be runaway growth by the end. Antiquity mega cities should have their population reduced and be half ruin at the start of Exploration. Some ruined urban tiles should have farms built over them for the entirety of the Exploration Age. In many ways, if Antiquity civilization was about consolidating technology and knowledge in cities, centralizing their effect, Medieval civilization distributed those technologies (monasteries, writing, crafts) which then allowed for modularity and colonization.

Another way to look at this problem is that in past Civ games, population can shrink. There's a demand for food, and it can be met, exceeded, or fall short. In 7, if I want to represent why Antiquity towns are smaller than in Medieval, it would have to do with antiquity having buildings with smaller food yields. However, that translates into fewer tiles developed and slower growth which isn't the point. Antiquity farming wasn't about growth rates, it was about max capacity (which 7 has no system for). Meanwhile, to mitigate slower growth as a calibration, that's what builders used to be about in how they could connect in farther flung resources. How do you work this into Civ.

I have a solution here:

• Antiquity towns are only 2 tile radius, at which point they cannot grow or be set to growing.
• Cities always have 5 tile radius for tall play.
• No settlement cap, distance from capital based settlement limits (so you can build many towns if they're close together, to mitigate smaller town radii to capture resources).
• Exploration halves city sizes, leaving ruins. Towns disappear but legacy effects let you replace some of them.
• Exploration towns now have 3 tile radius.
• Farming towns in exploration NO LONGER send food to cities. They specifically convert food to gold.
• Cities now have higher gold maintenance costs and will shrink without gold.
• Modern returns to the antiquity growth model, but with substantial boosts to food production.

Exploration is what will throttle the game to prevent snowballing, and with distant lands, has plenty of room for expansion to mitigate for the throttled city sizes. And, the fourth age, whatever it is, will introduce skyscrapers and things to accommodate population density, where you can actually convert farms back to nature from inherently high food production. Ideally, food production is almost trivial in this last age and social policies become more important.

Anyway, what do you think about population, growth, age theming, balance, design premise?

 

[Marla_Singer]

Paris didn't reach 1 million until 1850 and never got past 2 million.

Sorry to correct that but the administrative city of Paris only represents a very small area that is the city center of a very tight and dense built-up area of 12 million inhabitants.

If you believe that Paris is a 2-million city like Denver or Kansas City, you risk being very surprized when landing there.

 

[evonannoredars]

I don't understand where you're coming from with food being useless in antiquity at all. Having several dedicated farming towns does cause city populations to skyrocket in antiquity. Are growth rates even actually modified per age?

 

[tman2000]

I don't understand where you're coming from with food being useless in antiquity at all. Having several dedicated farming towns does cause city populations to skyrocket in antiquity. Are growth rates even actually modified per age?

Yes growth becomes easier with each age, the curve flattens from a smaller exponent.

Food is useless in antiquity. Food buildings especially. Farming towns can promote growth, but it's only a few growth events over the course of the entire age more than if you just stuck with a few farms in the city.

If you grow towns instead of specializing them, you can increase gold revenues. The margins on usefulness for towns is small. The only exception people bring up is in Modern (when growth rates are already more forgiving and food buildings much better), and when using fish factories (which is a known bug anyway).

This is the antiquity growth threshold breakdown:
30
34
46
77
139
248
418 Pop 7
666
1009
1466
2055
2795
3707
4810
6127
7678
9486
11572 Pop 18 - here growth becomes trivial, you're starting to look at 10-20 turns for an event with full farm support, pushing up to the end of the age.
13960
16674
19736
23171
27003
31257

 

[tman2000]

Sorry to correct that but the administrative city of Paris only represents a very small area that is the city center of a very tight and dense built-up area of 12 million inhabitants.

If you believe that Paris is a 2-million city like Denver or Kansas City, you risk being very surprized when landing there.

That's a good point, although if you look at before post-war sprawl, especially the Victorian Era (which the Modern Age represents), then Paris is about the size of Ancient Rome, having been much much smaller before then.

 

[tman2000]

Sorry to correct that but the administrative city of Paris only represents a very small area that is the city center of a very tight and dense built-up area of 12 million inhabitants.

If you believe that Paris is a 2-million city like Denver or Kansas City, you risk being very surprized when landing there.

If I calibrated 2 million inhabitants to 40 pop at 3-5 tile radius, then 10 million late 20th century sprawl would be 200 pop at 5-10 tile radius. This would mean surrounding towns are absorbed into suburbs, maybe into the urban core itself. This is also consistent with history.

A fourth age should have this feature, where city sprawl completely surrounding towns converts them into suburban centers where there's a little mini-icon that retains the suburb's name.

 

[kaspergm]

Without having read all the details of your post, I think you have some really important ideas and insights in some of the problems with the current design philosophy. Some random thoughts:

• I think the fact that cities can't lose population and don't need food to sustain their population in Civ7 is absurd and one of the worst design decisions ever.
• I love the idea of town (and city!) workable radius increasing with era. Imo. Towns should be something like 2-2-3 (or 1-2-3?), and cities should be 3-4-5 with eras (or even more). Yes to towns being absorbed into megapolises in modern age.
• I think food support for your population should be a serious limiting factor on city growth - NOT JUST stupid filling buckets for new population that then magically supports itself.
• I think food yields from farms (and also yields from other improvements) should increase significantly with technology (better tools, fertilizers, etc.). This should have the important result that you need fewer towns to support a city of similar size in later eras, possibly allowing you a higher city:town ratio in modern era than in ancient era (although modern mega cities should still require food from several towns).
• Modern technology like fertilizers should increase range with which a town can send food to a city (might already be a feature in the game).
• You should be able to control which city a town sends its resources to.

 

[Marla_Singer]

That's a good point, although if you look at before post-war sprawl, especially the Victorian Era (which the Modern Age represents), then Paris is about the size of Ancient Rome, having been much much smaller before then.

If I calibrated 2 million inhabitants to 40 pop at 3-5 tile radius, then 10 million late 20th century sprawl would be 200 pop at 5-10 tile radius. This would mean surrounding towns are absorbed into suburbs, maybe into the urban core itself. This is also consistent with history.

A fourth age should have this feature, where city sprawl completely surrounding towns converts them into suburban centers where there's a little mini-icon that retains the suburb's name.

Sorry but I'm sure you could find better example as the Victorian Era is what we could consider Paris Golden Age. It was the time when the city was entirely reshaped with large boulevards and Haussmanian buildings. It's also the time when was built the Eiffel Tower and the Paris metro. The city had 4 million inhabitants by 1900 in a very packed area (see graph below from Wikipedia). We're not talking about US-like sprawl in here, but 7-floor residential buildings.

Now talking about urban modelization in Civ7 is difficult to me as the sprawl on which it is based doesn't really make sense before the advent of rail and freeways. Before that it was very difficult to transit both people and goods. Therefore cities grew mostly on themselves with only taller buildings and narrower streets, and people were living in their workplace. That is also the reason why it was difficult for cities to really exceed 1 million people before the industrial revolution.

 

[tman2000]

• I think the fact that cities can't lose population and don't need food to sustain their population in Civ7 is absurd and one of the worst design decisions ever.

Yeah it turns out to be really important to making food management an actual trade-off, and they've had to make food irrelevant for most of the game to facilitate getting rid of it. Still, it's meant to create less micromanagement and I think we can work with their changes. That's the key though, population can't go backwards, so the city never has to be "fed", so you have to limit growth because all a city can do is become overpopulated.

• I love the idea of town (and city!) workable radius increasing with era. Imo. Towns should be something like 2-2-3 (or 1-2-3?), and cities should be 3-4-5 with eras (or even more). Yes to towns being absorbed into megapolises in modern age.

Yeah I know I said the thing about smaller Antiquity towns, but you've sold me on the idea over all. I think towns should be 2-3-4, and cities should be 4-3-5. If there's a 4th age, yeah, I think cities should grow to 10 tile radius and absorb other settlements, some policies enhancing it to 15. You wouldn't be able to grow all your cities that much (unless you're China!)

• I think food support for your population should be a serious limiting factor on city growth - NOT JUST stupid filling buckets for new population that then magically supports itself.

Yeah, but it is what it is. It's kind of abstracted. We're assuming that the peasants are supplying their own food and our yields are a surplus that administrators work with.

• I think food yields from farms (and also yields from other improvements) should increase significantly with technology (better tools, fertilizers, etc.). This should have the important result that you need fewer towns to support a city of similar size in later eras, possibly allowing you a higher city:town ratio in modern era than in ancient era (although modern mega cities should still require food from several towns).

Yeah, that's the idea. But interesting idea for a 4th age to drop towns altogether and just have cities and megacities. My idea is for antiquity and modern to have food grow cities, but in Exploration, due to peasantry, town food yields convert to gold, and cities consume gold for population purposes. I also think that Exploration cities can and should have depopulation events: plague, revolt, migration - if you can't sustain the gold. An exception would be Edo Japan which historically was unique in some ways for paying taxes in food, which became a monetary system. I think European feudalists sold their grain to a local market.

• Modern technology like fertilizers should increase range with which a town can send food to a city (might already be a feature in the game).

Okay I love this. I wanted a system for Antiquity where instead of settlement cap, distance from capital is mainly what affects your growth limits. I also want limits on how far towns can send food. Having that be unlocked in the Modern era via refrigeration and rail or something where you start being able to send food anywhere (so a continental bread basket can feed your entire global empire and you only need farms in two plains cities for like 50 settlements worldwide).

• You should be able to control which city a town sends its resources to.

Yeah absolutely, that's part of my mod concept. I want to target growing cities one at a time, or hyperfocus on a city to add specialists, or otherwise balance as I desire. Farming towns are kind of weak because of growth rate being tight, and my adjustments to growth rate go in the other direction and make farming towns less necessary. However, if you could control yields and combine the yields of many smaller farming towns, then you would have a reason to not keep growing them.

 

[tman2000]

Sorry but I'm sure you could find better example as the Victorian Era is what we could consider Paris Golden Age. It was the time when the city was entirely reshaped with large boulevards and Haussmanian buildings. It's also the time when was built the Eiffel Tower and the Paris metro. The city had 4 million inhabitants by 1900 in a very packed area (see graph below from Wikipedia). We're not talking about US-like sprawl in here, but 7-floor residential buildings.

Now talking about urban modelization in Civ7 is difficult to me as the sprawl on which it is based doesn't really make sense before the advent of rail and freeways. Before that it was very difficult to transit both people and goods. Therefore cities grew mostly on themselves with only taller buildings and narrower streets, and people were living in their workplace. That is also the reason why it was difficult for cities to really exceed 1 million people before the industrial revolution.

Thanks, that's great data. If Modern Age starts around 1850, Paris would begin around 2 million which let's say was Rome's size, in Civ 7 terms, 40 pop.

Then, halfway through Modern Age in 1900, the size has doubled. 80 pop. Then by 1950 it grows that same amount over again. 120 pop. This is about the end of the Modern Age.

I love the idea of rail unlocking city tile range increases, that's really perfect.

 

[UWHabs]

Definitely some interesting points here. If I could add a few potential suggestions:
-I feel that the settlement cap should adjust city/town balance too. Even something as simple as settlements counting 1 to your cap and cities counting 2 could give a little bit more of a "tall vs wide" balance feel.
-Towns having a smaller radius is great too. You probably don't even need to change the space between cities, it probably just means that right now where you leave gaps in your empire, those become the little feeder towns to fill in
-I love the idea of towns being able to basically being abandoned between eras. Maybe it could be something like when the era transitions, every town gets cut in half, and spawns a number of migrants equal to like half their previous era population. But maybe those town migrants can have a special ability that they can also found a new town within 1 tile of their previous location. So basically, on the era transition, the town goes away, and either the population can move to the nearest city, or else you can re-found a new town either in the same spot or close to where it used to be. You'd probably have to add a functionality so that when a town expands onto a tile with a previously abandoned building, maybe you pay a small price to "restore" it if you want.

Some of those are probably bigger changes that wouldn't be moddable, and would be more features for the civ devs. Definitely some ways to shift the balance even more between towns/cities and the age reset could add some fun changes.

 

[tman2000]

-I love the idea of towns being able to basically being abandoned between eras. Maybe it could be something like when the era transitions, every town gets cut in half, and spawns a number of migrants equal to like half their previous era population. But maybe those town migrants can have a special ability that they can also found a new town within 1 tile of their previous location. So basically, on the era transition, the town goes away, and either the population can move to the nearest city, or else you can re-found a new town either in the same spot or close to where it used to be. You'd probably have to add a functionality so that when a town expands onto a tile with a previously abandoned building, maybe you pay a small price to "restore" it if you want.

Yeah I was thinking that Antiquity should have 2-tile towns with a 2-tile min separation for settlements. Then, on age transition, the min separation raises to 3 and so all towns that don't qualify are deleted, and furthermore more towns are deleted half of all towns are deleted (although former cities don't get deleted). City populations are halved, including the capital, unless you get some legacy bonus to prevent this. Then, for each town you deleted you can replace them with a renamed town at the appropriate distance from other settlements, and for the population deleted from towns, you replace them into the new towns. Maybe even taking half the population deleted from cities (1/4 of the former pop) and adding them into towns as well.

The idea for exploration is that cities will be smaller, but can still grow rather large, and tall gameplay is less about absolute size, but instead about specialists and boosted yields that are well supported with appropriate buildings and maybe some support towns.