I wrote a program to do this a long time ago, and actually thought about writing a blog entry about the method I came up with.

Anyway, the method I devised is this:

Lookup the age category/life expectancy for the race involved.

Assume that for your population that there is an even distribution, across age.

If you had a pop. of 1000, and the life expectancy was 100, then that would be 10 people at age 1, 10 at age 2, etc. (math= pop divided by life expectancy)

Multiply this by the % of females in the population (50% for humans). This gets us 5 for a distribution.

Now look at the age categories, and figure out the breeding year range. This is basically the begining of adult hood, to the beginning of the last age bracket. Let's say for humans that's 20-80, which is 60 years. If you had to estimate, assume 1/2 or 2/3 of the life expectancy. This is the span.

Now folks don't crank out babies every year, it's simplest to statistically spread them over their breeding span. Divive the breeding span (60) by the age of maturity (20). We get 3. THat's basically 3 kids per person.

Multiply that by the first number, you get 15.

That means for a population of 1,000, whose life expectancy is 100 years, they will crank out 15 people next year. This seems plausible for humans.

Repeat that math for each year you want to pass.

The interesting mechanic is that a shorter lived race has a lower maturity, and they will basically crank out kids like candy.

Let's say you got 1,000 Kobolds that live to age 30, and mature at age 15.
1000/30*.5=16.67 population distribution
30/2=15 = breeding span
16.67*15=250baby kobolds next year


Now this formula is far from realistic or precise, but it's close enough, and the results compare well against real humans, and produces more babies for short lived races, less babies for long lived races. If you actually plug in real human numbers, it is remarkably close to American growth rate (at least it was when I designed it 15 years ago).

The mortality rate is sort of effectively applied by virtue of the life expectancy. Since Kobolds have a short life expectancy, it is already assumed lots of kobolds are dieing.

I designed this formula years ago, when I had an elven nation that had lost a lot of people in a war, and time was passing, so I needed to know how big they would grow back to, after 100 years after the war (barring other cataclysms).

If you're just looking for a generic answer to "time passed, how many people are in this empire or city?" it is close enough for government work.

Hint: Applying multiple years is easier if you write a small program to loop through the math and add it all up...or just stick it in a spreadsheet.

Janx

Way of the Tiger

Tora Meijin Lo Huang founded Tora No Do (“Way of the Tiger”) 200 hundred years when he was lost in the mountain hills. He searched for the way for hours when he caught glimpse of a white tiger. He followed the tiger, loosing sight of it, only to see it again as it led him. Finally he found himself on a road leading to his village. The tiger was no where to be seen. He arrived in his village to see invaders from the Dragon Clan attacking. He took cover, hoping to see an opening where he could save his people. From out of nowhere, the white tiger sprang into the center of the invading men and began tearing them to pieces. Lo Huang knew then that his time to strike had come. He leaped in among the men and fought with such ferocity that few of the Dragon Clan survived to run away. Villagers say that day that they saw only one tiger that day, and it was Lo Huang, savior of their village.



The Tora No Do style is an aggressive style preferring quick strikes against the enemy over advanced grappling, dodging and throws. Practitioners of this style are skilled in hunting their prey, having patience to wait for the opportune moment, and then to attack with full force and disregard for pain and injury, just as the tiger would.



As students advance in skill, they are recognized by being allowed to wear belts of the appropriate color. A student advances to a higher ranking by defeating a fellow student of equal ranking in an honor duel, the Shoushin Sainou.

The rankings are as follows:

Ranking, Monk Level, Belt, Title
Jukyu, 1, White, Tabite
Kukyu, 2, Yellow, Wakamono
Hachikyu, 3, Yellow 1 tassel,
Sichikyu, 4, Yellow 2 tassels,
Rokkyu, 5, Green, Wakamusha
Gokyu, 6, Green 1 tassel,
Yonkyu, 7, Green 2 tassels,
Sankyu, 8, Brown, Bushi
Nikyu, 9, Brown 1 tassel,
Ikkyu, 10, Brown 2 tassels,
Shodan, 11, Black, Sensai
Nidan, 13, Black 1 tassel,
Sandan, 15, Black 2 tassels,
Yondan, 17, Black 3 tassels,
Godan, 19, Black 4 tassels,
Rodan, 21, Red & White, Meijin
Sichidan, 23, Red & White 1 tassel,
Hachidan, 25, Red & White 2 tassels, Meijin Sensai
Kudan, 27 Red & White 3 tassels,
Judan, 30, White 1 tassel, Tora Meijin


One common misconception is that belt level rankings match a character’s level in Monk. The table above indicates an approximate Monk class level to a given belt level. Typically, a character must reach that level, before being allowed to participate in Shoushin Sainou. It is even possible for a character to be higher Monk level than belt level.



Basic Etiquette

Always bow before entering the dojo

Always remove shoes before entering a building (home or dojo)

Always bow to superior before speaking

Never interrupt a superior, wait to be acknowledged before beginning

Always bow when before leaving

Always address a superior by their title, not their name


The Shoushin Sainou

Each martial artist strives to attain mental and physical discipline. Their achievements are recognized by the Shoushin Sainou. It is a contest where all eligible students for a belt rank fight each other. The combat is non-lethal but brutal. The victorious student is promoted to the next level and the master puts a new belt or adds a tassle to the student’s belt. Some Shoushin Sainou have many students vying for the honor, and each round pits two students against each other in elimination tournament style.



The Batsu Fumeiyo

Honor is what binds society. Honor is gained through loyalty, duty, respect, and service to others. When that honor is forsaken, the Batsu Fumeiyo must be undertaken. As there are four ways of wind, there are four paths to honor, thus there are four parts to restoring one’s honor: Sacrifice, Pain, Humiliation, and Redemption. The Batsu Fumeiyo is required of one who has committed the greatest crimes. Few survive the ritual, but all have their honor redeemed.



Basic Combat Techniques (below black belt):

Punch
Reverse Punch
Back Fist
Spinning Back Fist
Uppercut
Reverse Uppercut
Throat Strike
Ridge Hand Strike
Reverse Ridge Hand Strike
Knife Hand Strike
Palm Strike
Double Palm Strike
Clenched Fist Strike
Elbow Strike
Round House Kick
Side Kick
Front Kick
Thrust Kick
Stomp Kick
Hook Kick
Axe Kick
Crescent Kick
Spinning Back Kick
Spinning Side Kick
Spinning Round House Kick
Spinning Hook Kick
Spinning Crescent Kick
Jump Front Kick
Jump Side Kick
Jump Round House Kick


Basic Blocks:

Overhead Forearm block
Middle Forearm Block
Downward Forearm Block
Double Forearm Block
Knife Hand Block
Double Knife Hand Block
Leg Check
Knee Block
Wrist Block
Double Wrist Block
High X Block
Low X Block


Dojos of Tora No Do

There are several dojos that teach the Way of the Tiger. They were formed by former students of Lo Huang and they have spread to distant lands.



Dojo of the White Claw

One such dojo is the Dojo of the White Claw. It is led by Meijin Shin Yu. The dojo teachs the philosophy of the Tao-Dan. There are 50 students at this dojo, of various ranks. Many of Master Yu’s pupils join the Navy Corps to serve as marines. The Dojo of the White Claw is located in the Wu Kyen province on the Tarais Island.



Resources:
http://japanese.about.com/blbeginkanji.htm

http://www.karatebc.org/history/

Janx