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Tanuki Tales
2014-02-02, 01:21 PM
So, enormous cities are a recurring theme in many fictions and tabletop games, sometimes getting as large as countries or even entire demiplanes at times. But using as much logic and verisimilitude as possible, how large can a city actually get before it would be impossible for it to function, leading to a fracturing and anarchy?

oudeis
2014-02-02, 01:37 PM
This table gives a pretty comprehensive picture of cities through the ages:

http://en.wikipedia.org/wiki/Historical_urban_community_sizes

Ravens_cry
2014-02-02, 02:16 PM
You more have to worry about food and water i think. That's something that most fantasy tends to forget is that cities don't grow practically all their own food, and so need huge amounts to survive. Since farming was more inefficient for manpower, you'd need huge tracts of land to provide enough food to feed the farmers, the support infrastructure for things they couldn't make themselves, save enough for replanting, and then, on the relatively small surplus, feed the cities. And that's not getting into things like feudal lords taxes and religious tithes.
In the city, you'll need waste management. It doesn't have to be sewers, but all those people, horses and other animals will mean a lot of crap. Besides, all that waste can be sold to tanners and farmers, so it makes sense to collect it.

veti
2014-02-02, 05:56 PM
What are the limiting factors on city size? I can think of:

Food
Water
Waste
Politics & economics

Food and water are both about "how much land is there around the city that it can draw food and water from?" Transport infrastructure is crucial in determining from how far away you can bring food into the city to sell it. Geography and geology will determine how much water you can draw from wells within the city (past the most rudimentary tech level, any river is most likely not going to be fit to drink).

Waste: rivers help enormously here. If there are large parts of your city that don't have easy access to a river, then you need some other solution, otherwise it'll rapidly become quite unlivable.

Of course, you can manage these factors away by throwing "magic" at them. But that sort of handwaving is a bit harder with the political/economic considerations. Basically: for any given community of 'N' thousand people, you need a sufficiently large segment of 'aristocrats' to draw the ruling class from. And for good social reasons, this segment will be largely hereditary (members of the class will tend only to trust people who've been born and raised within it), and non-working, at least not in the sense of anything we'd normally call "work". Where do these people get their (astronomical amounts of) money from?

Historically, the answer is "land" - they'd own large country estates, where they rent out land to the same farmers who produce the surplus that feeds the cities. But if the city doesn't have a large attached belt of agricultural land, you need some other system.

Urban landlords are the obvious answer, but that's a very different type of role from the traditional 'agricultural landlord'. Urban areas tend to change, quite quickly, and buildings need to be much more actively maintained (knocked down and replaced much more often) than happens in rural areas. So an urban landlord is a more active role, requiring significantly more work and time. (On the other hand, it's also incredibly lucrative.) The aristocrats in this case will have to be either (a) quite industrious and willing to get their hands, metaphorically at least, dirty, or (b) willing to trust their managers with large parts of their wealth and estates, in which case those managers will probably become the next generation of aristocrats.

If you want to get away from "landlords" as the focus of wealth, then the next stage is "capitalists". These are like urban landlords but more so - they need to take a very active interest in their businesses, and can't really afford to outsource their work to a "manager" class at all. Moreover, once you get to capitalism, you're in a world where technology and fashion are moving quite rapidly, and businesses will rise and fall - wealth is no longer guaranteed. That changes the dynamic of the ruling class, and it means a strict hereditary aristocracy/nobility isn't going to work any longer. Then the question becomes "how is this class selected?" Just "having money" isn't enough - you also need to know what to do with it and how to play the political system, which takes education and connections.

(In 19th century Britain, this is the problem that "public schools" were created to solve. If you'd made money in industry, you didn't buy your way directly into the aristocracy; instead, you bought an education for your children alongside the children of the existing nobility, meaning the next generation all mixed and networked and grew up together. However, this system has two obvious drawbacks: it's slow, and it depends on wealth being hereditary, which means the people who benefit from money are not the same as the people who made it. America's answer - "democracy", with all its mess and waste and attendant corruption - proved more flexible. But "democracy" ties power very closely to technology - you can only, realistically, buy/cajole/coax votes out of people you can reach, who have heard of you, and who think there is a chance you might do something for them. That limits the size of constituencies you can maintain depending on your communications technology.)

Tanuki Tales
2014-02-02, 08:44 PM
Well, couldn't also raw power suffice in the place of economic disparity? Like a slumbering physical god originally established the first community center that became the current city and the ruling class are its varying mortal offspring and descendants?

veti
2014-02-02, 09:16 PM
Well, couldn't also raw power suffice in the place of economic disparity? Like a slumbering physical god originally established the first community center that became the current city and the ruling class are its varying mortal offspring and descendants?

For the ruling class to - well, rule - they need to have some way of converting their "raw power" into favours for lesser beings. (Which is why the other people will, mostly and most of the time, do as they're told.) In our world, that's done with money. If you can think of a similar mechanism that works for "raw power", then you might be on to something there.

Tanuki Tales
2014-02-02, 10:09 PM
For the ruling class to - well, rule - they need to have some way of converting their "raw power" into favours for lesser beings. (Which is why the other people will, mostly and most of the time, do as they're told.) In our world, that's done with money. If you can think of a similar mechanism that works for "raw power", then you might be on to something there.

Don't dictatorships usually run on overwhelming force and fear though? I would think that unassailable raw power (either used to subjugate or as a protection racket from outside force) would be sufficient by itself, wouldn't it?

Lamech
2014-02-02, 10:12 PM
For the ruling class to - well, rule - they need to have some way of converting their "raw power" into favours for lesser beings. (Which is why the other people will, mostly and most of the time, do as they're told.) In our world, that's done with money. If you can think of a similar mechanism that works for "raw power", then you might be on to something there.
Perhaps they can magically create food, water, and medicine.

Mastikator
2014-02-02, 11:41 PM
Don't dictatorships usually run on overwhelming force and fear though? I would think that unassailable raw power (either used to subjugate or as a protection racket from outside force) would be sufficient by itself, wouldn't it?

Depends on what you mean by "raw power". A dictatorship would never be able to be maintained by the raw power of a thermonuclear bomb, even though that right there is a boatload of raw power. You're also gonna need to be able to dish it out in very small portions in very tactically precise locations all the time. Basically you need to spy on your citizens and have jack booted thugs kick in the door of anyone who thinks they can do better.
Unassailable raw power is however very useful against outside groups of equal power and size to your city that would want to invade and conquer.

Red Fel
2014-02-02, 11:57 PM
Don't dictatorships usually run on overwhelming force and fear though? I would think that unassailable raw power (either used to subjugate or as a protection racket from outside force) would be sufficient by itself, wouldn't it?

You're suggesting that the city is kept in line by enforcement. Possible, but it creates a new problem - instead of maintaining a unified city, you're trying to maintain a unified military force. A common issue with that is the possibility of military coup - after all, if the military is the source of all of your power, why shouldn't the military wield that power instead of you?

Further, a military is limited by resources. Suppose you have a massive city, a truly sprawling metropolis the size of a small state. Suppose there are rebellions and riots across that city. Your legions of terror can't be everywhere at once; there is a saturation point beyond which you cannot enforce your will everywhere.

Think of a city like an organism, then. Organisms have limits, internal limits and external ones, based upon their ability to grow. They grow to a certain, sustainable size, based upon access to nourishment and available surrounding space and hazards, and then cease to grow further. They continue to produce, of course, and that excess is sloughed off, either as digestive waste or as other waste byproduct, such as shed skin cells.

So, you have your city. It grows to fill the available area, either until it runs out of space in the countryside or until it can no longer sustain itself. Replace "nourishment" for the city with "resources" for the people; the inhabitants need space, food and water, waste disposal and other services, and a reigning government of some kind imposing order. While there is an abundance of all of the above, the population will grow. Once there is no longer an abundance, growth will equalize. Occasional surges will be offset by occasional drops, just as the body releases excess as waste.

What you're asking is whether a massive city can be held together by force; that answer, barring major magical shenanigans, is likely no. If a city is forced to grow beyond its means, it will collapse. A stable city or city-state is one which hits its saturation point and stops. There is enough government, enough food and water, enough public works to sustain the existing community. You get diminishing returns beyond that; even if you could provide more, you'd not be able to do so efficiently for the growing population. The city would fracture into sectors which have sufficient means and those which lack it, and troubles would start.

Coidzor
2014-02-03, 12:06 AM
Well, couldn't also raw power suffice in the place of economic disparity? Like a slumbering physical god originally established the first community center that became the current city and the ruling class are its varying mortal offspring and descendants?

At the risk of becoming more and more obsolete as society grew beyond them, I suppose so, yes. I'd wonder why these demigods weren't also entrenched as a wealthy hereditary aristocracy too though.

The city would still need to be administrated, blood would thin, and the things that are necessary for a city to survive or prosper would still need to be there and be done.

Tanuki Tales
2014-02-03, 01:13 AM
At the risk of becoming more and more obsolete as society grew beyond them, I suppose so, yes. I'd wonder why these demigods weren't also entrenched as a wealthy hereditary aristocracy too though.

I was just throwing out a hypothetical source of a ruling cast that wasn't based on land ownership or capitalism. It was the first thing to come to mind.

jedipotter
2014-02-03, 01:36 AM
So, enormous cities are a recurring theme in many fictions and tabletop games, sometimes getting as large as countries or even entire demiplanes at times. But using as much logic and verisimilitude as possible, how large can a city actually get before it would be impossible for it to function, leading to a fracturing and anarchy?

There is no limit. After all a ''country'' and a ''city'' are just words. For example we call Huston a ''city'' and Texas a ''State'', but we could call Texas a ''city''. So that Huston and Dallas are just ''neighborhoods'' of the ''city'' of Texas. You could even call America a ''city''.

Sidmen
2014-02-03, 02:55 AM
There is no limit. After all a ''country'' and a ''city'' are just words. For example we call Huston a ''city'' and Texas a ''State'', but we could call Texas a ''city''. So that Huston and Dallas are just ''neighborhoods'' of the ''city'' of Texas. You could even call America a ''city''.

If you called Texas a city, everyone else would be confused. Because words have meanings, and when you use a word in a way that isn't its meaning you are using it incorrectly.

"City" is a word that everyone knows the meaning for - it means a large continuous population center.

TuggyNE
2014-02-03, 03:00 AM
There is no limit. After all a ''country'' and a ''city'' are just words. For example we call Huston a ''city'' and Texas a ''State'', but we could call Texas a ''city''. So that Huston and Dallas are just ''neighborhoods'' of the ''city'' of Texas. You could even call America a ''city''.

:smallconfused:Four. Just because you call a tail a leg doesn't make it a leg.

TheStranger
2014-02-03, 08:58 AM
As others have noted, the generous application of magic (or sufficiently advanced technology) can remove pretty much all the upper limits on city size except for the political ones. (Sufficiently widespread mind-affecting magic could probably solve those, too, but let's leave that alone for now).

There actually is some gray area in how you define a city, though. For instance, if you have a contiguous urban area, but it's divided into multiple autonomous sections, is it still a single city? Does it matter if the sections are nominally under a central government but are effectively autonomous? What if the people don't think of themselves as being part of the same society as people in other parts of the city?

Any type of top-down power structure runs into a problem as city size increases towards the fantastical; it's literally impossible for any one person or group of people to deal with anything but the broadest policy issues, simply because of time constraints. So you have to insert more layers of government between the ruler(s) and what's happening on the ground, add some bureaucracy to handle it, and hope for the best. The bigger you get, the more intermediate levels you need. At some point, it becomes fiendishly hard to keep all those people moving in the same direction, and you start getting coups or outright civil war. Or the middle manager in charge of water supply for sector ZT-76 realizes that nobody's actually watching him and decides to set up his own little fiefdom.

All of which is to say, the human element is the real problem with this. Sooner or later (probably sooner), somebody is going to do something other than what they're "supposed" to, and things are going to get messy. If you're relying on extensive and fragile magic/sci-fi logistics systems to solve your food/water/waste problems, those systems are going to be disrupted.

Red Fel
2014-02-03, 09:22 AM
As others have noted, the generous application of magic (or sufficiently advanced technology) can remove pretty much all the upper limits on city size except for the political ones. (Sufficiently widespread mind-affecting magic could probably solve those, too, but let's leave that alone for now).

That's true. The Tippyverse is particularly famous for this - the use of massive teleportation methods and Create Food/Water resetting magic traps takes care of the vast majority of logistics, allowing entirely self-contained cities.


There actually is some gray area in how you define a city, though. For instance, if you have a contiguous urban area, but it's divided into multiple autonomous sections, is it still a single city? Does it matter if the sections are nominally under a central government but are effectively autonomous? What if the people don't think of themselves as being part of the same society as people in other parts of the city?

Also this. Consider, for example, New York City. It's divided into five boroughs, each one quite distinct in terms of culture and environment, each one in turn composed of many smaller yet equally distinct neighborhoods. Several are also geographically divided, such as Staten Island, Manhattan and the Bronx. They have different population levels, different industries, different income levels. In fact, some of the boroughs would probably qualify as populous cities on their own, but for the fact that they're considered part of the greater New York City. And that's all ostensibly within the "city," before you even start looking into the areas on the periphery. Other cities, such as Tokyo, may be even more elaborate.

In other words, it's rather difficult to tell what's a "neighborhood," what's a "borough," what's a "city," what's a "state," and even what's a "nation," by various metrics.


Any type of top-down power structure runs into a problem as city size increases towards the fantastical; it's literally impossible for any one person or group of people to deal with anything but the broadest policy issues, simply because of time constraints. So you have to insert more layers of government between the ruler(s) and what's happening on the ground, add some bureaucracy to handle it, and hope for the best. The bigger you get, the more intermediate levels you need. At some point, it becomes fiendishly hard to keep all those people moving in the same direction, and you start getting coups or outright civil war. Or the middle manager in charge of water supply for sector ZT-76 realizes that nobody's actually watching him and decides to set up his own little fiefdom.

Which is how states secede from a union, or colonies declare their independence, or, or, or... and so on. All it takes is for a single, reasonably self-identifying (even if not self-sufficient!) area to feel that it is no longer represented in or supported by the whole, and to take action to remove itself.


All of which is to say, the human element is the real problem with this. Sooner or later (probably sooner), somebody is going to do something other than what they're "supposed" to, and things are going to get messy. If you're relying on extensive and fragile magic/sci-fi logistics systems to solve your food/water/waste problems, those systems are going to be disrupted.

Yeah. Those darn humans make everything difficult. :smallwink:

TheStranger
2014-02-03, 11:06 AM
Another angle to think about is how the city got so big in the first place. In many ways, cities are about the aggregation of wealth. Real-world cities tend to crop up in places where wealth and power (which are largely interchangeable) accumulate for whatever reason, and they grow because people go to the city in the hopes that some of that wealth and power will make its way into their hands. Some of that wealth is created by the work of people in the city, some is created by people outside the city and accumulated in the city through trade, taxes, etc. So one practical limit on city size is the amount of wealth available; if people in the city are poor, people outside the city won't move there.

Anyway, that process of amassing wealth is a relatively slow one. Most of the world's major cities have been growing for hundreds, if not thousands, of years, and none of them have reached the absurdly large levels of genre fiction cities. And the size of modern cities is really only possible because of technology - not just because it solves some of the logistical problems, but because it aids in creating and accumulating the wealth that drives urban growth.

What I'm getting at is that cities don't just keep growing indefinitely without a good reason. To support a massive fantasy/sci-fi city, you need a proportionally massive amount of "not the city" to support it - not just in the sense of providing food and other resources, but to provide the wealth that drives the growth of the city and the people that migrate to it. And you need sufficiently advanced and ubiquitous magic/technology (mostly in the communications/transportation areas) that all of that wealth gets funneled into a single large city instead of creating numerous smaller cities. Then you need a vastly long period of time for that wealth to accumulate without any truly major disruptions.

All of that, however, is true primarily for conventional cities. It's possible that a tipping point occurs if a city can make all of its food and goods internally, but that's obviously not something we have any real-world experience with. If you can do that, you're asking what would happen if we could create an arbitrarily large amount of wealth from nothing. My guess is that you could see unchecked urban growth at that point, but it would still take a great deal of time, and your population is completely dependent on whatever systems you're using to create this wealth.

jedipotter
2014-02-03, 12:11 PM
If you called Texas a city, everyone else would be confused. Because words have meanings, and when you use a word in a way that isn't its meaning you are using it incorrectly.

"City" is a word that everyone knows the meaning for - it means a large continuous population center.

But the word City has no ''official'' size. A city is just a relatively large and permanent human settlement. San Dimas is a City that only has 33,000 people, but Chicago is a city with 2,700,000 some people. Both are cites, but one is much larger then the other. The city of Parker, Pennsylvania only has 800 people.

So Chicago is many times the size of Parker, but both are cities. Now picture a city that is as big as Chicago is to Parker. The city of Megatronea would have a population of 9,000,000,000 some. That is more then America......

Brother Oni
2014-02-03, 02:20 PM
But the word City has no ''official'' size.

If population numbers are your only metric for defining what a city is, then you're correct.
In reality, political and administrative factors decide what 'level' a population centre is.

Historically in the UK, a population centre needed certain buildings before it could be considered to be a city, town or village (a cathedral, a market and a church respectively): link (http://en.wikipedia.org/wiki/City_status_in_the_United_Kingdom).
These days it's arbitrary - compare Exeter (http://en.wikipedia.org/wiki/Exeter), a city of ~118 thousand covering ~18 sq miles, to Milton Keynes (http://en.wikipedia.org/wiki/Milton_keynes), a town of ~230 thousand covering 34 sq miles.

Tanuki Tales
2014-02-03, 04:12 PM
What I'm finding amusing is that the ultimate definition for what a city is, for Webster, is a city. I sifted through the connecting words and got it nailed down to "urban", which just is defined as "of, relating to, characteristic of, or constituting a city".

Nice work there dictionary folks. :smallwink:

Coidzor
2014-02-03, 04:17 PM
What I'm finding amusing is that the ultimate definition for what a city is, for Webster, is a city. I sifted through the connecting words and got it nailed down to "urban", which just is defined as "of, relating to, characteristic of, or constituting a city".

Nice work there dictionary folks. :smallwink:

It's like obscenity, you know it when you see it. There's a reason why the Sprawl in the U.S. is made of lots of different municipalities though, and not just out of tradition and the need for some semblance of the occasional greenbelt.

At the end of the day there's infrastructure and organization and the interrelationship between the two. As long as you can satisfy those, then you're good. The real question is where you draw the line for when you have to have faster than real time processing of information in order to keep up with the amount of input.

Ravens_cry
2014-02-03, 05:02 PM
Don't dictatorships usually run on overwhelming force and fear though? I would think that unassailable raw power (either used to subjugate or as a protection racket from outside force) would be sufficient by itself, wouldn't it?
You still need to have something they nominally want and they need to have something you nominally want. A successful dictator still needs to provide some measure of security to their subjects. You might be a slave but a slave needs to be fed, clothed, and housed, however poorly. In a world full of monsters roaming the country side, that might be enough to keep people in your city. Maybe.

Red Fel
2014-02-03, 06:59 PM
You still need to have something they nominally want and they need to have something you nominally want. A successful dictator still needs to provide some measure of security to their subjects. You might be a slave but a slave needs to be fed, clothed, and housed, however poorly. In a world full of monsters roaming the country side, that might be enough to keep people in your city. Maybe.

That's the whole concept of an effective LE tyrant. Or Caldwell B. Cladwell (http://en.wikipedia.org/wiki/Urinetown). Yes, they impose draconian measures on the people. Yes, their form of punishment may be grossly disproportionate. And yes, citizens are expected to be almost mindlessly loyal and obedient, or else they will suffer.

But the tyrant provides something in return. He ensures order. The Fascists made the trains run on time. Vlad the Impaler reduced crime within his realm, and kept the Ottomans at bay for years. A smart tyrant may even provide additional measures for his citizens, such as schools, hospitals, fitness and other services. This isn't out of altruism, but practicality - an educated, well-fed and healthy citizenry is a hard-working and loyal citizenry.

And Oceania has always been at war with Eastasia. (http://tvtropes.org/pmwiki/pmwiki.php/Literature/NineteenEightyFour)

genmoose
2014-02-03, 07:01 PM
Folks here have already done a very good job bringing up functions such as food, water, waste management, and most can be waved away with either a little magic or proper civil engineering (depending on the tech level of your game).

One point I want to raise as a factor in city size is why would people want to live there? In my experience living in a city trades certain problems (traffic, higher costs, higher crime, etc) for certain benefits (culture, job opportunities, entertainment, etc). If benefits > problems, the city grows [New York] if benefits < problems, the city will fracture or shrink [Detroit].

So depending on your setting, I'd look at what benefits a giant city may bring. Here are a few ideas:

1. Transportation hub. Perhaps the city is located on a major river or other natural highway. Or maybe it is a hub for teleportation or extra dimensional travel. You could have a giant sheltered, deep water port, or the only pass through steep mountains.

2. Cheap, plentiful energy. This could depend on your technology level but perhaps the city is on a giant waterfall and it provides huge amounts of hydro power. You could have a steady lava flow that allows for cheap forges. Or perhaps the city is located on some mystical energy source that cheaply powers spells and items.

3. Economics. Through the reasons above or something else, people who work in the city make significantly more money than those folks in the countryside. This could be due to trade, natural resources [fish, gold, ore, etc], magic, synergistic cooperation or a combination of all.

4. Safety. Despite all the crap that comes with urban living, being outside the wall is far worse. At least in the city, people are relatively safe against whatever unknown horror exists in the wilderness.