“ Rather than making a baddy impossible to hit, consider giving it mega-hit points.
Super hard to hit leads to great player frustration. Allowing them to do damage leads to a sense of accomplishment. another variation of this would be to give the bad guy a forcefield that shows damage.You could also give them a mastermind ability that sluffs the damage of to minions who should be easy to kill.Once in a while a super high to hit encounter is ok ,but it should be few and far between.
Your mileage may vary”
“ Somewhere along the line, someone very powerful lost their marbles. Literally. Possessing a marble allows incredible clarity of thought about a particular related subject.”
“ 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.”