Eberron`s internal consistency.

[S'mon]

I also find the military demographics of most fantasy worlds to be laughable. In ancient times, the Romans likely had over 1,000,000 soldiers spread across their empire.

Assuming you're not talking about the 1st century BC Civil Wars period & counting all the (opposing) Roman armies, this is incorrect. During the empire a generous estimate would be 250,000 troops, including auxiliaries, naval, & Praetorian forces. The remaining Roman legions after Teutoburger Wald numbered 23 AIR, with about 3,000 Legionaries on average in each (nominally 5,000, in practice this was never achieved).

I don't have a quibble about fantasy city sizes, the place designers usually fall down is in it not having nearly enough rural population to support the cities they do have, with unrealistically low population densities in settled rural areas. Food-growing humans will have a village every few miles (2-4 miles) down the track, with rural population density 100/square mile or so in wheat-growing areas. Even if much terrain is unfarmed moors & mountains, like medieval Britain, you'll still get a population of 2-4 million in 100,000 square miles, ie _minimum_ average population density over the realm is around 20/square mile. A flat, fertile realm like medieval France or Oerth's Great Kingdom will have a much higher density - France had ca 25 million over 200,000 square miles, or 125/square mile, with 90% or so of this being rural population.
I don't see anything in fantasy demographics that would change this - most fantasy countries still seem based on peasant agriculture with little magical interference.

 

[S'mon]

BTW, I would not hold too much faith in the numbers given that Xerxes invaded ancient Greece with a million men. Ancient and medieval sources loved to boost the numbers in their histories, so while it was formidable it may not have been a million.

Thucydides actually put Xerxes' army at 2.5 million + 2.5 million camp followers, or 5 million!! Modern estimates put it at ca 600,000, still the largest single army ever fielded in the ancient world AFAIK. Personally I suspect it might have been smaller, but probably still in the hundreds of thousands. If the figure really was 600,000 I think the Persian empire must have needed a population base of ca 50 million to support these numbers, but I don't think that's implausible, eg the fertile crescent was a lot more lush in those days than currently.
Of course medieval armies were different in nature and far smaller than these ancient imperial armies; in 1000 AD europe 10,000 men really was a huge army; William conquered England in 1066 with little over half that.

 

[Gez]

i think the continent's demographics as a whole are far too low, even given the major war that just ended. i think someone in another thread estimated that the population density of the continent was around 2 people per square mile.

that's lower than the population density of the Gobi Desert or the Sahara.

obviously, Eberron includes vast tracts of lightly-populated wilderness, but i'd be interested in seeing what the population densities of the settled lands are. i have a feeling they'll be much, much lower than even post-Black Plague Europe.

Are monsters (owlbears, winter wolves, gray renders, etc.) counted as population? It's a D&D world. It needs a lot of space for monsters.

Are monstrous humanoids and giants counted as population?

For sheer internal consistency, the population density can't be equal to that of Earth in historic time. The ecosystem can't support a Renaissance-era population density plus monsters and dragons. Given the wide variety of various predatory monsters, you probably have to give them between one-half and three-quarters of the territory and game.

Which means you must divide population density by at least two, and probably more.

 

[S'mon]

"For sheer internal consistency, the population density can't be equal to that of Earth in historic time. The ecosystem can't support a Renaissance-era population density plus monsters and dragons. Given the wide variety of various predatory monsters, you probably have to give them between one-half and three-quarters of the territory and game."

- So monster-inhabited fertile territory is 'unihabited' wilderness, just likes deserts, swamps etc. This doesn't change the fact that human-inhabited, monsterless territory (ie likely all the habitable territory within state borders, otherwise those states are unable to protect their populations) ought to have much higher population densities than the given figures.

 

[Thengil]

I was under the impression that London had something like 45,000 inhabitants in the Roman era, and 18,000 inhabitants in the 13th century?

 

[Gez]

- So monster-inhabited fertile territory is 'unihabited' wilderness, just likes deserts, swamps etc. This doesn't change the fact that human-inhabited, monsterless territory (ie likely all the habitable territory within state borders, otherwise those states are unable to protect their populations) ought to have much higher population densities than the given figures.

Usually in D&D, there are monster-infested zones within countries.

I haven't Eberron, so I don't know if, in this setting, there are clear-cut "Here Be Monsters" no-man's-land and Guaranteed-100%-Monster-Free nations, but I kinda doubt it.

Protecting the population, in D&D, is usually building high walls around cities, patrolling roads, and hiring adventurers to periodically clean up the Ghost Ruins of the Dried Tears, the Sinister Slug Swamps, the Sulfur Mines of the Fiery Abysses, and the Friendly Local Dark Temple of Unspeakable Insane Horrors From Beyond Reality.

My point stands.

 

[d4]

For sheer internal consistency, the population density can't be equal to that of Earth in historic time. The ecosystem can't support a Renaissance-era population density plus monsters and dragons.

but to support a Renaissance-era type of civilization, a certain amount of infrastructure (including settled and cultivated land) is required. at the population densities we're talking about here (2-4 people per square mile) it becomes much, much harder to support.

also, that land must usually be rather compactly connected. if a nation did have large swaths of monster-haunted wasteland within its borders, it'd be very hard for it to remain a unified nation. trade and communication are vital for a nation. if a city is cut off from its rural hinterland, it starves to death. if the rural hinterlands are cut off from the city, they lose their source of manufactured goods and regress.

that's why i've asked before about determining the amount of settled land on the continent. obviously taking the civilized population and the total area of the continent is going to give a very skewed result. i'd like to see what the population density of the actual settled regions is.

Given the wide variety of various predatory monsters, you probably have to give them between one-half and three-quarters of the territory and game.

that's quite high, i'd think. if powerful predatory creatures were so common that they needed that much room, i'd think there wouldn't be any civilization left -- or hardly any prey for that matter.

 

[S'mon]

that's quite high, i'd think. if powerful predatory creatures were so common that they needed that much room, i'd think there wouldn't be any civilization left -- or hardly any prey for that matter.

That would be my feeling too - states may claim areas of unsettled monster-haunted wilderness (or for that matter wilderness inhabited by humans outside the state's control, like the tribal areas in NW Pakistan or the Scots highlands through much of the middle ages), within their nominal borders that they don't really control, but these will be frontier areas away from the main internal arteries of trade, commerce, pilgrimage & troop movement. If that takes up 1/2 the state's nominal area that seems high, but ok. Population in the _settled_ areas of the state still needs to be around 20-40/square mile, not 2-4. Most of Australia is, of course, effectively uninhabited wilderness.

 

[Hand of Evil]

I like the population numbers, by keeping them down you do not run into that 20th level wizard in every town issue of the FR.

I have to find the numbers but on earth population was constaint until the industrial revolution. Up until then population would migrate, moving to a new area then blooming and yet being reduced in others, then flatten out.

 

[Hand of Evil]

that's quite high, i'd think. if powerful predatory creatures were so common that they needed that much room, i'd think there wouldn't be any civilization left -- or hardly any prey for that matter.

Ratio is 20/80 (real world) meaning that 20% of your wildlife is predators. Predators share the area with their prey, conflict arise when predators compete for the same prey. The larger the hunting area the less chance of conflict.

The question is in what group do you put the core races.