Lord of the Hidden Layer
Black Death engulfs Medieval Europe, the PCs are in its path, and that section of the 1e DMG gets some actual use.On the subject of disease, there are definitely time periods and settings that, if I were basing a campaign in them, I'd be including notable disease events. I'm not entirely sure I'd trot out the 1e DMG's disease/parasitic infection checks... but you never know.
(That kind of campaign ceased being interesting to me ... just under two years ago now. We have to IRL a distorted variant.)