“ Mining in a certain area turns all exposed skin (maybe just parts that are actively disturbing the chemicals that cause the reaction) of the those doing the mining to a dark blue color. Will wear off taking as many years/days spent in the mine. ... meeting a party of blue-skinned humans armed with pick-axes etc. Strange disease? Demon offspring? Curse? If they meet only one ex-worker, they will very carefully listen to any stories he says, no matter if drunken or insane, or just makes up to get a beer.”
“ You realize a group of men is going right to you. The man in front has a hard determined look on his face, the two men behind follow him with some uneasiness. He stops before you, holding the handle of his sword in one hand, and slaps (choose person carefully) with leather gloves he carries in the other hand. 'Rhadagald Thinvoice, I challenge You to a duel to dea...' Stopping abruptly, he realizes this is the wrong person.”
“ 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.”
