Elephants crossing the seas!
It is not an infectious disease, but it is a plague upon the world.
For it spawns villains. And not your garden variety villains, but epic villains, master villains of the most dangerous kind Evil Geniuses.
Pnathic sorcery has existed for ages, crudely used by magi who no idea the true forces they were fumbling with.
An article concerning the nature and role of druids in an RPG enviroment.
Plagues and other great diseases are important parts of history and some settings. They defy man and may even defy God in their swift and terrible punishment upon the body of society.
"Ladies and Gentlemen of Worth, please come closer and have a look... " In a little stand with numerous maps, the human Advantos sells land-rights with a shining smile and jovial talk at bargain prices. He sells even squatter rights (first to settle is the owner). About 20% of the lands do not exist or belong to someone else. About 30% do not have even that value, or have other problems attached- swampy, cursed, haunted, Old Indian/Pet Cemetery (tm)... Be assured you will not see this man in the same city twice.