As much as I would love to get into a debate with Nik on the plague its causes so on I will keep it on topic to the game implications. Nice to see though there are people whom like good debate!
Some Stats I dug up:
In Chapter 5 of A Distant Mirror, by Barbara Tuchman provides the following statistics:
·While the plague raged, Pisa and Vienna lost 500 people a day.
·Florence, Venice, Hamburg and Bremen lost a minimum of 60% of their populations.
·At the peak of the epidemic, Paris lost 800 people a day, and by the end of its long run with the disease (which lasted there until 1349), half its population of 100,000 people had died.
http://users.cybercity.dk/~dko12530/blackdeath.htm
The Link above is a obscure corner of the web, the author doesn’t list resources for his statistics but makes a couple of decent points regarding record keeping of the time. The Clergy did most of the scribing in the middle ages and one has to wonder if the plagues effects and tolls weren’t somewhat exaggerated by said clergy for psychological and populace manipulation purposes.
http://www.hopkins-biodefense.org/pages/agents/agentplague.html
“In 1346, the second plague pandemic, also known as the Black Death or the Great Pestilence, erupted and within 5 years had ravaged the Middle East and killed more than 13 million in China and 20-30 million in Europe, one third of the European population”
The above quote and link are from the John Hopkins university website.
So in game terms the plague of 1347-???? Would have to be completely devastating to a economic and social structure of an effected region, particularly provinces with ports and high commerce. Based on historical documentation or more accurately historical interpretation based on hypothesis, it has to be a major factor in the game. Because it would happen so late in the game play most majors would already be carved out, houses/dynasties roots formed. The plague could really splinter a nation into smaller groups or estates and weaken a dynasties line. My preference would be for this to actually happen as I stated, for revolts, secession of provinces by other lords (as hinted at by Nik in his comment about estates widening). You would have 75 years roughly to tie things up before the end of the game, and then the file could be transferred to the EUII game with the dynastic claims in tact from the fallout of the plague.
Just some thoughts.
Odin