In creating an adventure, there will be a major meterological event causing massive damage to the town's infrastructure. In the aftermath, there will be a pretty significant outbreak of at least one disease or plague. I've looked, but haven't found any statistics on plagues. I know Paladins are immune to normal disease, and some spells can cure disease, but nothing on actually getting infected, suffering from, or dying from any disease.
I have a rough idea on what it might do, but don't know if what I think will happen would be mild, significant, deadly, or TPK (besides the paladin).
Assuming the characters survive this (which I think will be somewhat difficult), do they get XP for surviving? How would I determine how much XP they should get for surviving? I figure some characters will get infected, and others may or may not get infected at all.
Best Answer
Yes, for D&D 3.5 the Pathfinder Adventure Path "Curse of the Crimson Throne" deals with a plague in the city of Korvosa and they've published some various rules for diseases and plagues. Specifically, Seven Days to the Grave has an article entitled "Plague and Pestilence: Diseases of Fantasy and Reality", which besides having diseases and gear relevant to diseases has some treatment of larger scale plagues (outbreaks, epidemics, and pandemics). Then they updated those rules to Pathfinder as part of the Affliction rules in general and added a lot of real-world tropical diseases in the recent Heart of the Jungle supplement.
And lucky for you, a lot of that has found its way into the Disease section of the Pathfinder SRD!
Here's how it works, I'll illustrate with my favorite sample disease, dysentery.
This means that when you're exposed you have to make a Fort save DC 16 or else you get the disease and it manifests symptoms in 1d3 days. You make a new save every day once it manifests and if you fail you take 1d6 nonlethal and are fatigued and staggered. You have to make 2 consecutive saves to get better; with this one it doesn't run its course otherwise.