But this raises many questions:
1) how do they sprout
2) how do they spread
3) how does the population becomes inmune naturally
4) how do you find a cure or vaccine to inmunize artificially
5) how to use it as a weapon
suggested answers:
1) flood plains in the earlier game, or randomly. I only know for sure how emerging diseases such as ebola HF and HIV sprout: by colonizing virgin jungle areas (the other side of the tourist resort coin)
2) trade routes. geographical closeness. great merchants. even rivers.
3) aqueducts, sewage, TIME, food resources, and perhaps MEDICAL Resources such as quinine for malaria!!! that's a good one for when a vaccine can't be yet discovered.
4) pretty obvious, by discovering the technology
5) terrorists obviously, but also by founding a city in a foreign continent you should be able to infect those civilizations with your germs, and viceversa, but one is gonna be worse than the other.
1) Indeed, virgin jungle is the most obvious origin, but this would lead to a balancing issue, so it might need tweaking. The only other option that I can think of would be to make incredibly unhealthy cities sprout disease but then it becomes easily avoidable.
2) yes TRADE ROUTES, rivers, proximity, etc.
3) I don't know if immune is the right word, chances are your population will decimated and so the disease will retreat naturally but without having researched it properly it could return. But yes aqueducts, sewers, medicine.
4) I imagined when one of your cities becomes infected you gain the option to research that disease, after the first round of testing you would slow its spread because you understand how it is transferred. You then get to research its treatment and its eradication.
5)I don't think you should need to found a city to spread it, nor need to be a "terrorist", it is only considered terrorism because biological warfare has been outlawed. Give the in game UN the power to outlaw biological weapons and add some. A few for example would be an espionage mission, a missile/warhead like a cruise missile that can be loaded onto a sub, or an ICBM, or a unit (would need to be built in an infected city) and would have a high chance to infect any city it go close to.
Where was it I was talking about giving spies promotions, I already mentioned a hacker promotion but a terrorist promotion could give an increased chance of success for destroy building missions. And you could just add a suicidal option for sabotage production and destroy building, and I guess the spread disease mission too, it would greatly increase chance of success and lower the espionage cost, it would just sacrifice the spy of course.
Just thought of this whilst I was writing
my answers to those questions, it would be nice if you could divide your research amongst different topics, of course dividing it equally doesn't make sense (you could research two techs in the same time and finish one earlier). So instead your civ specialises, it has biologists, chemists and physicists, if you fund biologists more then your biology research
recruitment improves to the detriment of your other lines and so the rate you can research biological technologies improves. This would add a team aspect where two civs can get together and suggest one concentrates on biology and chemistry and the other the other focuses on physics and they trade techs. Now my example of the breakdown isn't great, perhaps instead it should be scientific, mathematical and philosophical. Basically I want to be able to research different things at the same time, it came from the thought that you might have a tech that is going to take ages to research like curing Aids but you don't want to stop everything else just put it on the back burner. So I think I came up with two ideas there. I'm going to start a new thread.