“ It is traditional for two warlike countries to each give their first-born royal prince as a hostage to each other to prevent war. One of the princes has been murdered, and the PCs have a few days to rescue the prince in the other country to save him from being executed and a bloodthirsty war from breaking out.”
“ 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...”
“ The PC's end up in a strange world where the very rocks are made of gold and jewels.As such gold and jewels is worth very little, but the iron in their swords and belt buckles is suddenly worth a LOT.”