Troth Glenbeard was a dwarf with a mission. And that was destruction.
From there, things happened. And the Irondeeps got a Subterranean-Transport-System-That-Moves-Things-Around-Faster-Than-Equine-Means (aka, in modern-speak, a subway).
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...