“ Pick up a pathology/microbiology book, and add the diseases/syndroms to your game. Your players will freak out.
Coughed at? Diphteria. or tuberculosis?
Drunk from a muddy stream? Or just walked through? Well, let us introduce you to schistosomiasis...
Hit by a stream of energy? Too moch mana is ust like too much radioactivity - perhaps all mages could develop cancer early if too powerful...”
“ Head priests of a order are buried sitting up with their skeletal hand sticking out of the ground so worshippers can still kiss his hand for a blessing.”
“ A Deity of some sort has unleashed a plague of bookworms or something like that in the area. Almost all spellbooks are destroyed, along with bardic and historical books.”