Of course, doing the research necessary to find out how common a large city should be, or how common castles are, or how many shoemakers can be found in a town, can take up time not all GMs have available. To the end of more plausible and satisfying world design, I've prepared this article.

The information her is distilled from a variety of historical sources, focusing on results, rather than on the thousands of details that create them. The rules here are meant to serve as a baseline, to be deviated from at need, not to cast numbers into iron - halve things, double things, or otherwise fiddle with them to suit the feel you're going for. The figures employ documented data from time periods ranging from the 12th-14th centuries, and from locales as varied as Russia, England, France, Germany and Italy. When a "default" was needed, rather than an average, I opted for late-medieval France more often than not, and the latest, most developed periods in general.

Population Density: How Many In That Kingdom?

Unless the kingdom is quite young, it is likely riddled with villages, a mile or so apart, covering every inch of the countryside. Agrarian communities on the scale of the village or hamlet are not self-supporting in any real sense; they exist in vast networks. The only notable exception to this rule is frontier country, where isolated towns have no choice but to exist. But these towns will tend to be large and walled—a people huddled together for safety. On the frontier, food and goods are usually delivered by merchant caravans rather than produced by local agriculture. The presence of monsters would almost certainly magnify these effects.

The average population density for a fully-developed medieval country is from 30 per square mile (for countries with lots of rocks, lots of rain, and lots of ice—or a slave-driving Mad King) to a limit of about 120 per square mile, for a land with rich soil and favorable seasons. No land is wasted if it can be settled and farmed. There are many factors that determine the population density of a land, but none as important as arability and climate. If food will grow, so will peasants. If desired, exact density can be rolled randomly, and land arability reverse-engineered from the result. A roll of 6d4, multiplied by five, will do the trick nicely. Reduce the multiple by any amount down to 1 to represent a much less developed land, or to represent countries depopulated by invasions, plagues or other calamities.

Some Historical Comparisons: Medieval France tops the list, with a 14th-century density in the neighborhood of 105 people/sq. mile. The French were blessed with an abundance of arable countryside, waiting to be farmed. Modern France has more than twice this many people. Germany, with a slightly less perfect climate and a lower percentage of arable land, averaged 87 people per square mile. Italy was similar (lots of hills and rocky areas) with 86. The British Isles were the least populous, with only 42 people per square mile, most of them clustered in the southern half of the isles.

Hexes: It may be important for some GMs using this article to know how much land is in a hexagonal area! To determine the area of a hex, multiply its width by 0.9306049, and square the result. Thus, if your game-map has hexes 30 miles across, each hex represents about 780 square miles. Put a hex like that in the middle of 14th century Germany, and it supports an average of 67,800 people (and it's a convenient size for travel-times, since 30 miles is a good rule of thumb for a day's road travel on foot or horseback).

Town and City Population: How Many In Those Walls?

For purposes of this article, settlements will be divided into Villages, Towns, Cities and Big Cities (known as "supercities" in the parlance of urban historians).

Villages range from 20 to 1,000 people. Most kingdoms will have thousands of them. Villages are agrarian communities within the safe folds of civilization. They provide the basic source of food and land-stability in a feudal system. Usually, a village that supports orchards (instead of grainfields) is called a "hamlet." Occasionally, game writers use the term to apply to a very small village, regardless of what food it produces.

Towns range in population from 1,000-8,000 people. Culturally, these are the equivalent to the smaller American cities that line the interstates. Cities and towns tend to have walls only if they are frequently threatened.

Cities tend to be from 8,000-12,000 people, with an average in the middle of that range. A typical large kingdom will have only a few cities in this population range. Centers of scholarly pursuits (the Universities) tend to be in cities of this size, with only the rare exception thriving in a Big City.

Big Cities range from 12,000-100,000 people, with some exceptional cities exceeding this scale. Some historical examples include London (25,000-40,000), Paris (50,000-80,000), Genoa (75,000-100,000), and Venice (100,000+). Moscow in the 15th century had a population in excess of 200,000!

Large population centers of any scale are the result of traffic. Coastlines, navigable rivers and overland trade-routes form a criss-crossing pattern of trade-arteries, and the towns and cities grow along those lines. The larger the artery, the larger the town. And where several large arteries converge, you have a city. Villages are scattered densely through the country between the larger settlements.

Population Spread

Okay, so you know how big your kingdom is, and how many people live there. How many people live in the cities, and how many cities are there? How many live in villages?

• First, determine the population of the largest city in the kingdom. This is equal to (P times M), where P is equal to the square root of the country's population, and M is equal to a random roll of 2d4+10 (the average roll is 15).
• The second-ranking city will be from 20-80% the size of the largest city. To randomly determine this, roll 2d4 times 10% (the average result is 50%)
• Each remaining city or town will be from 10% to 40% smaller than the previous one (2d4 times 5% - the average result is 25%); continue listing them until you hit a town with a population below 1,700. Once you do, you'll have a complete list of every urban center in your kingdom, ranging from the largest city to the smallest of the notable towns.

The remainder of the population will be rural, living in villages and hamlets and huts and so on. Individual village populations should be determined randomly or by fiat (the average will be from 100 to 600 or so depending on cultural and climate factors). From 2-5% of the country's populus will live in settlements too small to be called villages—isolated dwellings, or collections of huts with a total population of under 20—or will be itinerant workers and wanderers.

An Example Kingdom: Chamlek

Chamlek is a smallish island kingdom with an area of 70,000 square miles, with a good climate and only a few rocky hills disturbing a well-watered countryside. Her population is 5.25 million, for an average density of about 75 people per square mile (an average roll of the dice using the recommended range for a developed land).

Using similarly average rolls for city sizes, we can determine the following about Chamlek: It's largest city, Restagg, has a population of 34,000. The next-ranking major cities and towns are Volthyrm (17,000), McClannach (13,000), Cormidigar (10,000), and Oberthrush (7,000). There are 4 cities and 6 towns all told, with a total population of around 98,000 (nearly 2% of the kingdom). The rest is rural. Keeping all rolls average but varying the starting population density, Chamlek could have from 4-5 towns and from 1-5 cities.

Merchants and Services

In a village of 400 people, just how many inns and taverns are realistic? Not very many. Maybe not even one. When traveling across the countryside, characters should not run into a convenient sign saying "Motel: Free Cable and Swimming Pool" every 3 leagues. For the most part, they will have to camp on their own or seek shelter in people's homes.

Provided they are friendly, the latter option should be no trouble. A farmer can live in a single place all his life, and he will welcome news and stories of adventures, not to mention any money the heroes might offer!

Each type of business is given a Support Value (SV). This is the number of people it takes to support a single business of that sort. For instance, the SV for shoemakers (by far the most common trade in towns) is 150. This means that there will be one shoemaker for every 150 people in an area. These numbers can vary by up to 60% in either direction, but provide a useful baseline for GMs. Think about the nature of the town or city to decide if the numbers need to be changed. A port, for instance, will have more fishmongers than the table indicates.

To find the number of, say, inns in a city, divide the population of the city by the SV value for inns (2,000). For a village of 400 people, this reveals only 20% of an inn! This means that there is a 20% chance of there being one at all. And even if there is one, it will be smaller and less impressive than an urban inn. The SV for taverns is 400, so there will be a single tavern.

Some other figures: There will be one noble household per 200 population, one lawyer ("advocate") per 650, one clergyman per 40 and one priest per 25-30 clergy.

Businesses not listed here will most likely have an SV from 5,000 to 25,000! The "Magic Shop" means a shop where wizards can purchase spell ingredients, scroll paper and the like, not a place to buy magic swords off the shelf.

Agriculture

At the medieval level of technology, a square mile of settled land (including requisite roads, villages and towns, as well as crops and pastureland) will support 180 people. This takes into account normal blights, rats, drought, and theft, all of which are common in most worlds. If magic is common, the GM may decide a square mile of land can support many more people. Please note that the number of people a square mile of agricultural land will support is not the same as the maximum population density for a kingdom.

Once you have decided the ability of the land to support people, you can determine the amount of wilderness/unfarmable country in the kingdom by working backwards. Take the example kingdom of Chamlek again, the island kingdom with 70,000 square miles and 5.25 million citizens. With one square mile supporting 180 people, that means there is approximately 29,200 square miles of developed agrarian land — about 42% of the total area of the isle. This offers a graphic example of just how sparse the population really is. The remaining 58% of the country is wilderness, rivers and lakes.

Even if Chamlek had the maximum population density (120 people per square mile), the farmland would be a whopping 2/3rds of the total land, leaving one-third of the country to wilderness (mostly forested hills between the farms) and waterways. This is the maximum achieved on Earth, though higher is theoretically possible if the GM determines that the entire country is arable.

While the average distance between population centers can be derived from the total land area, the average walking distance from one village to the next is more realistically determined by considering only the settled land. Villages and towns tend to cluster tightly along the arteries of travel defined by the lines between the cities — leaving gaps of wilderness in the middle.

Castles

Okay, we now completely understand the lay of the land as regards civilization, the cities and farms. Nearer to the heart of the adventurer, however, is the castle, or better still, the ruined castle. Once again, how many should there be?

Ruins, first of all, depend on the age of the region. The following formula is only a guide. The frequency of ruins in Europe varied greatly depending on military history and remoteness of the area. To determine the approximate number of ruined fortifications, divide the kingdom's population by five million. Multiply the result by the square root of the kingdom's age. If the kingdom has changed hands a lot, use the total age—the number of years that castle-building people have lived there, regardless of the Royal Lineage.

Chamlek, our island kingdom, has five-and-quarter million people today. Chamlek has been populated by castle-building folk for 300 years. She has 18.19 ruined forts or castles, which means 18 for sure, and a 19% chance of one more.

Active castles are much more common; ruins are rare because the solid ones are constantly put back into service! Assume one functioning castle for every 50,000 people. The age of the kingdom is not really a factor. Chamlek would have 105 active castles of various stripes, approximately.

75% of all castles will be in the civilized (settled) areas of a kingdom. The other 25% will be in the "wilderness," along borders, etc.

The role of these castles is something too world-oriented to be reduced to formula. Most will mark the landholdings of Barons and Dukes, but some may be bandit strongholds, or the outposts of Goblin warlords. It is all up to the GM.

Miscellany

City Size: Cities and towns of the Middle Ages cover one square mile of land per 38,850 people, on average. This is a density of about 61 per acre or 150 per hectare, so the land within the walls of a typical city of 10,000 would be 165 acres—hardly a city by modern standards, in terms of population OR size. Some very large cities may have had up to twice this density.

Law Enforcement: A well-kept medieval city will have 1 law officer (guardsman, watchman, etc.) for every 150 citizens. Slack cities will have half this number. A few rare cities will have more.

Institutions of Higher Learning: There will be one University for every 27.3 million people. This should be computed by continent, not by town! This figure assumes entirely scholarly universities, not those dedicated to the arcane arts. Whether or not magical universities are separate institutions, and how common they are, is a matter for GM decision.

Livestock: The livestock population, on the whole, will equal 2.2 times the human population, but 68% percent of this will be fowl (chickens, geese and ducks). The rest will be dairy cows and "meat animals:" Pigs are superior as food animals, since they eat less individually, and are not picky eaters. Sheep will be extremely common if the region has a wool market (like medieval England, which was built on wool). Cattle for labor and milk will be found occasionally, but cattle raised specifically for meat are only found in very prosperous areas.

Bibliography

The SV list was taken (mostly) from the tax list of Paris in 1292, and checked against other sources for accuracy. This list can be found in Life in a Medieval City by Joseph and Francis Geis (Harper and Row, 1981). This is a fine book by amateur historians, which includes some fascinating descriptions of medieval city life and layout. Other books consulted include:

Medieval Cities, by Henri Pirenne. Doubleday.

The Castle Story, by Sheila Sancha. Harper Colophon.

The Medieval Town, by John H. Mundy and Peter Riesenberg. Robert E. Krieger Publishing Company.

The Medieval Town, by Fritz Rörig. University of California Press.

Medieval Regions and Their Cities, by Josiah Cox Russel. David & Charles press.

Questions about the article? Visit the Blue Room FAQ; I have an entire section devoted to this article. Please read the FAQ before emailing.

This piece has really made the rounds . . . The earliest version was rejected by Dragon magazine back in 1993. I dusted it off, expanded it, and submitted it to Pyramid after that (no response at all). I improved it further for my own use, then sold it to The Familiar - just in time for them to vanish. After the obligatory touches of improvement, I sold it again, to Shadis, just in time for them to vanish! Now, I've given it a home where it can rest, and hopefully be discovered by people that won't reject it, ignore it, or go out of business after touching it (and, just recently, another popular gaming magazine approached me wanting to publish it, so I guess there's no rest for the wicked)!

Demographic Spreadsheets: A nice chap named Marcus Hulings has designed a spreadsheet inspired by earlier versions of this article. This handy ZIP archive (26k) contains the file in both Excel and Quattro Pro formats. Another nice chap, Anthony M. Plum, did a spreadsheet, too; it's available from his site by clicking here (29k ZIP, Excel format).

Online Demographics Calculators: Brandon Blackmoor has created an excellent Javascript version of the material; I can't use it in my primitive old browser, but I've heard nothing but nice things about it! An Australian gamer named Bronwyn Evans created two online calculators likewise based on the material here (one for general kingdom-scale stats, and another for city businesses). Douglas Schulz made an outstandingly groovy online calculator that doesn't require any kind of browser voodoo at all. If you're reading this page at all his calculator will probably work perfectly - including a great implementation of the random values (which I highly recommend, and the Schulz calculator uses by default).

Demographics in French: French gamer Antoine Dinimant has placed la Démographie médiévale facile on the Web for those who dig French to enjoy. It's a translation of this article, with additional notes added from our correspondence!