Disease Model v1.3

[Lord God Jinnai]

http://clash.apolyton.net/models/Model-Disease.shtml

Previous discussion:

http://apolyton.net/forums/showthrea...threadid=12194

[Lord God Jinnai]

Name/ viral, bacterial / rate / Location Code
Bubonic Plague / B / 15-30% / plains near India I

^Cholera / B / 10-20% / Arabia J

^Dysentery / B / 10-20% / Most likely Africa H

$Dengue Fever / V / 10-20% / Most likely Africa B

^Diphtheria / B / 5-10% / Most likely Africa F

Hantavirus / V / 15-30% / plains near India H

Influenza / V / 1-20% / Europe A

Leprosy / B / 1-2% / Arabia A

$Malaria / V / 5-10% / African jungles C

Measles / V / 1-5% / Arabia/Egypt A

$Sleeping Sickness / V / 5-10% / African jungles B

Smallpox / B / 5-10% / Arabia/Egypt D

Syphilis / B / 1-5% / America/Caribbean A

^Tuberculosis / B / 5-10% / Europe E

^Typhus / B / 5-10% / Europe C

Whooping Cough / V / 1-5% / Europe C

$Yellow Fever / V / 5-10% / Most likely Africa B

my only comment is i think some of these diseases are paracitical, ie not baterica or viruses

[LDiCesare]

While reading the Guns germs and Steel book and checking the disease model at work when I could squeeze some time, I mailed myself a few comments to post here later.
Roughly, I think that many things modelled in the disease model could use the same underlying mechanisms as the tech model uses (applications being diseases, with a corresponding tech, and additional techs reducing their effects). The main difference with regular techs being that diseases are probably to be checked province-wise and not civ-wise.

Here are my comments on the model:

Reading the Disease model alongside Guns Germs and Steel, I had a few
ideas.
One is: Diseases could use the tech model. In that sense, disease
resistance is like a tech which increases if you are in contact with other
civs knowing the tech, and which would receive RPs when you suffer deaths
from it (roughly as Military Tactics does when you suffer deaths from
fights).

That way, disease resistance would be a direct function of disease
resistance tech level, which in turn would be increased by biology/medical
research, if the tech is known. It would have helpers in biology...
Diseases would be applications, with a disease tech and a helper tech like
domestication (more cattle = more diseases). Here I disagree with the model
that say higher domestication tech means less disease. It is the proportion
of the population that handles animals which is important (thus 1- number
of farmers 2-use of animals in fields/transportation).

What do you think?
Can the tech model provide all the figures needed to make out diseases? Does it provide a sufficient framework to account for diseases, or does disease need its own model to check for evolution of diseases/resistances, and then how does it handle its relationships with techs like medicine/domestication?

I also think the model should have steepest resistance effects, like:
Initial epidemic damage dealt by smallpox = 30% of population for
resistance 1. Resistance grows to 2, epidemic damage reduced to 15%. If
resistance of population beats disease resistance, risk of epidemia is effectively eradicated.

Current model:
Disease damage outside epidemics = str+5-resistance + random (varies with disease inside 0-4 range) heads/10 million.

General Critics:
Disease pools: As said, balanced but not very realistic?
Province based: Looks good to me.
Jungle based: No. Many diseases don't stem from ungles.
Emerging: OK.
Measles, smallpox, flu should have higher epidemic damage because they did kill whole populations. It is not because they are currently benign or eradicated that they are not deadly.

I suggest disease virulence (damage it deals, e.g. smallpox 30% - ebola 40% - flu 10%) to be fixed, then strength to vary with strains, and mutations/whatever. Strength is to be compared with resistance, the idea being that :
Epidemics damage = virulence/resistance(resistance min 1). Chance of occurring = F(strength-resistance).
Non epidemic damage = G(strength-resistance) * virulence

If str-resistance is too big, then str can change towards resistance.

Resistance should diminish if sanitation is poor. Disease resistance should be an application dependant on the corresponding tech and existing infrastructure. Problem is that this tech would be province-wise rather than civ-wise.

[Mark_Everson]

Hi Laurent:

That is an interesting idea. Personally I have doubts that the tech model can be mutilated sufficiently to support disease handling without making the code pretty opaque and confusing. However some of the code might be used in setting up the disease model through the expedient of taking the relevant tech code and then heavily modifying it. (Not through inheritance but by making new classes.)

In terms of the basic way that disease functions, I do think that keeping it as close to tech as possible would be an intriguing way to give the game fewer complicated models that the power players will want to understand.

[LDiCesare]

I thought more of taking the parameter classes (those which make computation of a level based on a lot of other stuff) common to both models, along with the formula which increases the level (through RPs in the tech model).
The idea is to share code, not duplicate it, so there is less to modify, and so it is easier for tech to affect disease model (the same tech affects military without the military actually doing much beyond providing a few RPs here and using the tech dependant parameters).

[Mark_Everson]

Hi Laurent:

Well, if your idea can be made to work without introducing undesired consequences it would help to reduce the coding burden. I guess we'll just have to see what the person who ends up coding it thinks is the most practical approach.

[Lord God Jinnai]

I think the idea could work well...with some modifications...
1> it should be very hard for disease to be downgraded at all in potency....not impossible, but even harder than tech slideback.

2> only more restitant strains should give neighbor rps to the same disease of equal or lesser stength.

3> Deaths shouldn't be the only thing to measure...in fact death should get negative...or atleast no bonus. Here's my reason why:
Diseases are similar to parasites...in fact some are. A parasite only survives contentidly so long as its host survives contentidly so the longer it can stay alive and multily the better. Diseases that kill too quickly don't get too far.

4> humans can 'weaponize' diseases as well as make new ones.

5> Climate should also affect rps for disease...it doesn't for techs...except for few specific ones...but colder, dryer climates have less disease than wetter hotter climates.



As far as origins...yes and no...many [non-water borne] diseases in ealier time periods start in jungles, old-growth forest and wetlands....there were exceptions of course.

In modern times, diseases also origin in densly populated areas, including densly populated farms.