“ If mana recovered slowly enough, and mages could pass it on freely between them, the ephemeral force would become a valuable trading commodity on its own.”
“ The PCs have been traveling for a long time down the same stretch or round with no sign of anything suspicious. As they cross over to the next hill they see a gigantic splater of blood with a bleached dragons scull in the center of it. It the dragon skull's mouth is a tattered backpack with something wiggling inside of it.”
“ What if the sources of precious metal in the realm all failed, so that the only sources for gold and other precious metal were hostile foreign lands? Gold coinage might become increasingly rare, resulting in hoarding. Player characters that appear with masses of treasure might be suspected of being in the pay of foreign powers.”