# Population Density Shift Mechanism

From the rulebook, “ACKS generally assumes that between 10% of the population lives in urban communities and that around 20% of the realm’s urban population lives in its largest settlement.”

In the example given in the book the kingdom has a advanced society that causeed you to shift the down on the table which increased the percentage from 10% to 50%.

How did you arrive at that number or how do recalculate the percentage if you shift up?

The math behind some of these tables is hard to determine, even with the examples provided.

OK,

Here is the example for the book that I am having a problem with.

EXAMPLE: The Judge wants to create the realm of Achea, a city-state ruled by a powerful overlord. He has determined that Achea has a population of 40,000 families (200,000 people), controlling about 5,000 square miles (making it a large duchy in ACKS.) With a peasant population of 40,000 families, Achea would normally have an urban population of about 4,000 families, while the largest settlement would normally be a town of around 800 families.

However, Achea is an advanced urban realm, so the Judge shifts downward 2 rows on the Urban Population column, and gives Achea an urban population of 20,000 families (50% of its total). An urban population of 20,000 families would normally mean the largest urban settlement is a Large City of about 4,000 families.

Since Achea is a city state, the Judge shifts 2 rows downward on the Largest Settlement column and gives Achea a single Large City of 10,000 families (Class II).

I bolded the part I am having an issue with.

How did you determine it was 50% of its total?

Does each shift up and down have a incremental value?

It is not clear at all in the book about this and I searched these forums and I have yet to find an anwser.

The judge in the provided example picked values within the ranges provided on each row - he or she wasn't using a system - which is a completely valid way to do it.  He or she decided to go 50% all the way down.

So the short answer is that the percentages don't matter as long as you're picking something within the ranges on the new row.

The values given on each row are just guidelines to show you what would be generally expected.

So, Achea has 40,000 families, and an original assumption that 10% of that, 4,000, is the urban population. That puts it at Row 7 on the Villages/Towns/Cities placement table, bolded and italicized:

 Realm/Domain ``````

Population

(families)

Urban

Population

(families)

Largest

Settlement

(families)

Monthly

Income

Market

Class

31,250-62,499

3,125-6,249

Large town (625-1,249)

370-739gp

Class IV

62,500-124,999

6,250-12,499

Small city (1,250-2,499)

740-1,474gp

Class IV

125,000-249,999

12,500-24,999

City (2,500-4,999)

1,475-2,950gp

Class III

``````

Note each row gives you ranges of 10% of the total population for Urban Population, then 20% of that for the Largest Settlement.

We want more folks in the urban areas, so we shift down two rows, from Row 7, in the Urban Population Column.

 Realm/Domain ``````

Population

(families)

Urban

Population

(families)

Largest

Settlement

(families)

Monthly

Income

Market

Class

31,250-62,499

3,125-6,249

Large town (625-1,249)

370-739gp

Class IV

62,500-124,999

6,250-12,499

Small city (1,250-2,499)

740-1,474gp

Class IV

125,000-249,999

12,500-24,999

City (2,500-4,999)

1,475-2,950gp

Class III

``````

Implied there is a shift downward on the Largest Settlement size as well - it's more people living in the same number of urban settlements, not more urban settlements over all (though you could do that)

At this step, there's a few ways to figure out your new Urban Population

You could do it by making it up, that's what happened here. The Judge pegged his new Urban Population at 20K families, which is 50% of his total population of 40K. Picking pretty much anything within that range of 12.5K->24.9K would be fine.

You could also do it by ratio - which is what I do because I'm OCD about dumb stuff - we originally said 40K/4K rural and urban. 4,000 urban families is 28% through the 3125-6249 range of Urban Population in Row 7. So, by ratio, 28% through the 12.5K-25K range in Row 9 would be about 16K urban families.

The second step down takes our Largest Settlement to Row 11.

 Realm/Domain ``````

Population

(families)

Urban

Population

(families)

Largest

Settlement

(families)

Monthly

Income

Market

Class

31,250-62,499

3,125-6,249

Large town (625-1,249)

370-739gp

Class IV

62,500-124,999

6,250-12,499

Small city (1,250-2,499)

740-1,474gp

Class IV

125,000-249,999

12,500-24,999

City (2,500-4,999)

1,475-2,950gp

Class III

250,000-499,999

25,000-49,999

Large city (5,000-9,999)

4,700-9,399gp

Class II

500,000-749,999

50,000-74,999

Large city (10,000-14,999)

9,400-14,099gp

Class II

``````

Again, in the book, the presiding Judge decided to wing it and pick 10K families, going with 50% again.

By our previously calculated 28%, I would set my largest settlement size at 11.4K families. (28% of the range of 5000 on Row 11)

In a default 40K realm, the urban population is 10% of the total (4K) , and 20% (800 families) of the urban population lives in the largest settlement.

The Judge in the book took a 40K family domain, and gave it a total urban population of 20K families (50%) with a Large City of 10K families (50% of that).

My method took that 40K domain, gave it a total urban population of 16K (40%) and a Large City of 11.4K families (71% of that).

They're both within the general ranges, though I like mine better because it's much more City-State-y.

Thanks Man,

I am OCD and an accountant and it was driving me crazy. I like the ratio and will go with that.