“ You receive a vision of a rooftop 'somewhere close by', where a rare moss grows; in the vision, you know the moss is suitable for greatly enhancing the effects of certain types of potions. Now go and find that rooftop. Don't fall off. (Of course, rooftop runners *will* be taken for miscreants by the local City Watch....)”
“ If you want to add a 'supernatural' touch to your campaign, define the rules of magic and the universe. Make your players comfortable with those rules. Then your new supernatural creatures must then break those rules.”