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Disease Model
Disease Model
Disease Pools
To determine what diseases a culture starts with, disease pools will have to be established first. There would be 12 disease pools. Distribution would begin at the tropics. Each tropical pool would get 2 jungle diseases and 1 water-borne disease. Each of the temperate pools would get 1 of the 2 remaining water-borne diseases and 2 other diseases. Then the arctic pools would get 2 diseases from the remaining 5 and would share the last one. Then each culture would get it's number of initial diseases from it's disease pool. If a culture is in 2 or more disease pools, it will select from the pools it was in.
Here is an example of what one game's disease pools might look like:
sub/arctic 1(Influenza, Bubonic Plague, Typhus) 7(Whooping Cough, Leprosy, Measles)
temperate 2(Diphtheria, Hantavirus, Measles) 8(Tuberculosis, Syphilis, Influenza)
sub/tropical 3(Malaria, Yellow Fever, Cholera) 9(Yellow Fever, Dengue Fever, Diphtheria)
sub/tropical 4(Sleeping Sickness, Dengue Fever, Dysentery)10(Sleeping Sickness, Malaria, Cholera)
temperate 5(Tuberculosis, Smallpox, Leprosy) 11(Dysentery, Bubonic Plague,Smallpox)
sub/arctic 6(Syphilis, Whooping Cough, Typhus) 12(Typhus, Hantavirus, Measles)
Initial Diseases
Initial Diseases will represent those the people have previously been exposed to. Every province of every Civ. and barbarian "Culture" in the game will start with 1-3 diseases from the 19 modeled in the game. This assumes that each different cluster of any barbarian culture will be treated as a different province (ex. If culture #17 is divided by Roman territory, each half would be treated as a different province). By modeling every province rather than the Civ/Culture as a whole we can allow for greater diversity and realism in the system with only a few extra calculations.
To calculate the number of initial diseases a civ has, we would generate a number (1-10) then modify it by population density and climate. Climate would modify the number based on the zone the Province is located in:
Climate Zone{Modifier(+/-)}[#of DiseasePools]
Sub-arctic/Arctic {3} [4 pools]
sub-arctic/Temperate {2}(a culture would use this modifier if it overlaped both zones listed)
Temperate {1} [4 pools]
Temperate/subtropical {-2} (a culture would use this modifier if it overlaped both zones listed)
Subtropical/Tropical {-3} [4 pools]
Once modified for climate zone and density, the number of diseases is as follows:
Modified Number /Number of Diseases
1 or less / 3 Diseases
2-4 / 2 Diseases
5 or more / 1 Disease
Disease Table
Disease / Mortality rate / Str. Increase
Bubonic Plague B /15-30%/ 2
^Cholera B /10-20%/ 3
^Dysentery B /10-20%/ 5
$Dengue Fever V /10-20%/ 4
^Diphtheria B /5-10%/ 5
$Ebola V /15-30%/ 2
Hantavirus V /15-30%/ 3
$HIV/AIDS V /1-5%/ 4
Influenza V /1-20%/ 4
Leprosy B /1-2%/ 5
$Malaria V /5-10%/ 3
Measles V /1-5%/ 5
$Sleeping Sickness V /5-10%/ 3
Smallpox V /5-10%/ 4
Syphilis B /1-5%/ 5
^Tuberculosis B /5-10%/ 3
Typhus B /5-10%/ 3
Whooping Cough V /1-5%/ 4
$Yellow Fever V /5-10%/ 4
^ = water-borne;
$ = jungle;
* = Ebola and HIV/AIDS are never initial diseases but come in later in the game to preserve some history to disease.
V = viral
B = bacterial
How Disease Works
For every disease a culture has it will also have a resistance number for that disease. Every disease will also have a strength(str.). It is by comparing these two numbers we will determine what effects a disease will have:
-If disease str. is less than the culture's resistance there is no effect.
-If disease str. is equal to or greater than the culture's resistance, a "check" is made. (A check is a random number, 1-100, that is generated for str. then str. is subtracted from it; the same is done for the resistance. The lower number is the winner.)
An example of how the check works:
---Disease str. is 35 and Resistance is 30; a 15 is generated for str. and a 36 for Resistance; after subtracting str. from 15 you get -20 and 36-30 is 6, so the disease "wins" the check and has it's effect.
-If the resistance wins the disease has no effect.
-If the disease wins there is an epidemic, and a loss of population equal to the mortality rate of the disease. This loss is for one turn only! When an epidemic occurs, resistance increases by 1-5
-If it is a tie, then nothing happens and a check is made again next turn.
Some other things to keep in mind:
-Base resistance is 25 for all diseases, except initial diseases, which is 50.
-Base disease str. is 15-25 (Regardless of what str. it is at when transmitted to a new culture, a new str. will be determined. However, the range on it will be the difference between the numbers above and actual disease str. For example, if transmitted at str. 55 the disease str. for the new culture would be 40-30, or 30-40.)
-Disease str. and resistance can never exceed 100 (except if strains are used, then disease str. can reach 110, but only during flare-ups.)
-Disease str. increases by 1 every number of turns listed on the chart.
Spreading Disease
Whenever any kind of contact is made between two civs/cultures (merchants, armies, migrations, etc.) there would be a chance, equal to the home culture's resistance, of the disease spreading. Also when a civ encounters jungle, there would be a chance (equal to the disease str. in that region) of them catching a jungle disease and possibly bringing it back home.
Ebola and Aids will have a 25% chance of infecting anyone who travels in the jungle, however only after whatever turn the year 1900 occurs on.
Note: When Migrations occur, add +1% per head, or fraction thereof, for the percentage chance of disease spreading.
Modifiers to Resistance/Mortality Rate
-improvements: temples (of religions that care for sick), hospitals, etc. will each have individual effects
-famine will reduce resistance temporarily, while famine continues, by -3 per turn (cumulative).
-technology- some will have individual effects on diseases, chance of spreading or Mortality rates (like vaccinations will cure some diseases).
-overcrowding, -3 for every province with 1,000,000 of population, and an additional -1 for every 500,000 afterwards.
Strains
*This is just an idea I'd like to get some feedback on though it may be just a bit too complicated for the game*
Each disease will have several strains active until sufficient contact has turned it into a single strain. An example would best explain this:
The Greeks have smallpox (strain one) and the Egyptians have smallpox also (but strain two). Upon contact & transfer of both strains between the 2 civs, there would be a flare-up (+10 to disease str. for one turn) of the disease as the two disease pools collide and meet new cultures. Then these two strains would be annialated and would become strain three (a new strain) within both civs.
Now if the Greeks had given the Romans strain one previously but no longer had contact with them, strain one would survive with the Romans but the Greeks and Egyptians would have strain three (strain two would be annialated). But if the Greeks again contacted the Romans and transmitted strain three, and they still had good contact with the Egyptians, all three would then have strain four, and strains one, two and three would have been annialated.
Strains would never be seen by the player, they would only help simulate flare-ups of disease as disease pools collide. They would also simulate a decrease in flare-ups as sufficient contacts are made between cultures thereby increasing the size of the disease pools.
Agricultural Disease
[This message has been edited by Toubabo_Koomi (edited January 05, 2000).]
[This message has been edited by Toubabo_Koomi (edited January 05, 2000).]
Disease Pools
To determine what diseases a culture starts with, disease pools will have to be established first. There would be 12 disease pools. Distribution would begin at the tropics. Each tropical pool would get 2 jungle diseases and 1 water-borne disease. Each of the temperate pools would get 1 of the 2 remaining water-borne diseases and 2 other diseases. Then the arctic pools would get 2 diseases from the remaining 5 and would share the last one. Then each culture would get it's number of initial diseases from it's disease pool. If a culture is in 2 or more disease pools, it will select from the pools it was in.
Here is an example of what one game's disease pools might look like:
sub/arctic 1(Influenza, Bubonic Plague, Typhus) 7(Whooping Cough, Leprosy, Measles)
temperate 2(Diphtheria, Hantavirus, Measles) 8(Tuberculosis, Syphilis, Influenza)
sub/tropical 3(Malaria, Yellow Fever, Cholera) 9(Yellow Fever, Dengue Fever, Diphtheria)
sub/tropical 4(Sleeping Sickness, Dengue Fever, Dysentery)10(Sleeping Sickness, Malaria, Cholera)
temperate 5(Tuberculosis, Smallpox, Leprosy) 11(Dysentery, Bubonic Plague,Smallpox)
sub/arctic 6(Syphilis, Whooping Cough, Typhus) 12(Typhus, Hantavirus, Measles)
Initial Diseases
Initial Diseases will represent those the people have previously been exposed to. Every province of every Civ. and barbarian "Culture" in the game will start with 1-3 diseases from the 19 modeled in the game. This assumes that each different cluster of any barbarian culture will be treated as a different province (ex. If culture #17 is divided by Roman territory, each half would be treated as a different province). By modeling every province rather than the Civ/Culture as a whole we can allow for greater diversity and realism in the system with only a few extra calculations.
To calculate the number of initial diseases a civ has, we would generate a number (1-10) then modify it by population density and climate. Climate would modify the number based on the zone the Province is located in:
Climate Zone{Modifier(+/-)}[#of DiseasePools]
Sub-arctic/Arctic {3} [4 pools]
sub-arctic/Temperate {2}(a culture would use this modifier if it overlaped both zones listed)
Temperate {1} [4 pools]
Temperate/subtropical {-2} (a culture would use this modifier if it overlaped both zones listed)
Subtropical/Tropical {-3} [4 pools]
Once modified for climate zone and density, the number of diseases is as follows:
Modified Number /Number of Diseases
1 or less / 3 Diseases
2-4 / 2 Diseases
5 or more / 1 Disease
Disease Table
Disease / Mortality rate / Str. Increase
Bubonic Plague B /15-30%/ 2
^Cholera B /10-20%/ 3
^Dysentery B /10-20%/ 5
$Dengue Fever V /10-20%/ 4
^Diphtheria B /5-10%/ 5
$Ebola V /15-30%/ 2
Hantavirus V /15-30%/ 3
$HIV/AIDS V /1-5%/ 4
Influenza V /1-20%/ 4
Leprosy B /1-2%/ 5
$Malaria V /5-10%/ 3
Measles V /1-5%/ 5
$Sleeping Sickness V /5-10%/ 3
Smallpox V /5-10%/ 4
Syphilis B /1-5%/ 5
^Tuberculosis B /5-10%/ 3
Typhus B /5-10%/ 3
Whooping Cough V /1-5%/ 4
$Yellow Fever V /5-10%/ 4
^ = water-borne;
$ = jungle;
* = Ebola and HIV/AIDS are never initial diseases but come in later in the game to preserve some history to disease.
V = viral
B = bacterial
How Disease Works
For every disease a culture has it will also have a resistance number for that disease. Every disease will also have a strength(str.). It is by comparing these two numbers we will determine what effects a disease will have:
-If disease str. is less than the culture's resistance there is no effect.
-If disease str. is equal to or greater than the culture's resistance, a "check" is made. (A check is a random number, 1-100, that is generated for str. then str. is subtracted from it; the same is done for the resistance. The lower number is the winner.)
An example of how the check works:
---Disease str. is 35 and Resistance is 30; a 15 is generated for str. and a 36 for Resistance; after subtracting str. from 15 you get -20 and 36-30 is 6, so the disease "wins" the check and has it's effect.
-If the resistance wins the disease has no effect.
-If the disease wins there is an epidemic, and a loss of population equal to the mortality rate of the disease. This loss is for one turn only! When an epidemic occurs, resistance increases by 1-5
-If it is a tie, then nothing happens and a check is made again next turn.
Some other things to keep in mind:
-Base resistance is 25 for all diseases, except initial diseases, which is 50.
-Base disease str. is 15-25 (Regardless of what str. it is at when transmitted to a new culture, a new str. will be determined. However, the range on it will be the difference between the numbers above and actual disease str. For example, if transmitted at str. 55 the disease str. for the new culture would be 40-30, or 30-40.)
-Disease str. and resistance can never exceed 100 (except if strains are used, then disease str. can reach 110, but only during flare-ups.)
-Disease str. increases by 1 every number of turns listed on the chart.
Spreading Disease
Whenever any kind of contact is made between two civs/cultures (merchants, armies, migrations, etc.) there would be a chance, equal to the home culture's resistance, of the disease spreading. Also when a civ encounters jungle, there would be a chance (equal to the disease str. in that region) of them catching a jungle disease and possibly bringing it back home.
Ebola and Aids will have a 25% chance of infecting anyone who travels in the jungle, however only after whatever turn the year 1900 occurs on.
Note: When Migrations occur, add +1% per head, or fraction thereof, for the percentage chance of disease spreading.
Modifiers to Resistance/Mortality Rate
-improvements: temples (of religions that care for sick), hospitals, etc. will each have individual effects
-famine will reduce resistance temporarily, while famine continues, by -3 per turn (cumulative).
-technology- some will have individual effects on diseases, chance of spreading or Mortality rates (like vaccinations will cure some diseases).
-overcrowding, -3 for every province with 1,000,000 of population, and an additional -1 for every 500,000 afterwards.
Strains
*This is just an idea I'd like to get some feedback on though it may be just a bit too complicated for the game*
Each disease will have several strains active until sufficient contact has turned it into a single strain. An example would best explain this:
The Greeks have smallpox (strain one) and the Egyptians have smallpox also (but strain two). Upon contact & transfer of both strains between the 2 civs, there would be a flare-up (+10 to disease str. for one turn) of the disease as the two disease pools collide and meet new cultures. Then these two strains would be annialated and would become strain three (a new strain) within both civs.
Now if the Greeks had given the Romans strain one previously but no longer had contact with them, strain one would survive with the Romans but the Greeks and Egyptians would have strain three (strain two would be annialated). But if the Greeks again contacted the Romans and transmitted strain three, and they still had good contact with the Egyptians, all three would then have strain four, and strains one, two and three would have been annialated.
Strains would never be seen by the player, they would only help simulate flare-ups of disease as disease pools collide. They would also simulate a decrease in flare-ups as sufficient contacts are made between cultures thereby increasing the size of the disease pools.
Agricultural Disease
[This message has been edited by Toubabo_Koomi (edited January 05, 2000).]
[This message has been edited by Toubabo_Koomi (edited January 05, 2000).]
A refined description of reality is IMO not necessary, especially if it complicates things with relatively little added fun for the player. No player is going to care if his flu outbreak is Sydney A Influenza, or the Michigan strain!
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