Rich Countries are wealthy countries. Their wealth gives their population access to better drugs which slows down the infection rates of the player's plague, and they typically have ten research facilities, making their medical funding contribute greatly to the Cure. However, not all countries with ten research facilities are rich countries. Drug Resistance 1 helps to moderately speed up infection in rich countries while Drug Resistance 2 virtually negates the fact that the country is rich all together making it a very useful trait when playing in a more aggressive fashion. Drug Resistance 3 and Drug immunity are only available in certain plague types, making Drug Resistance 2 the highest level of drug resistance one can get, mostly. Surprisingly, Drug Resistance 3 and Drug immunity are actually cheaper than the previous, making them highly recommended, should one be in a game in which they are available.