“ 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”
“ Alchemical Gold - popular in the weapons of the nobility, this allows for gold to be used in their swords and lances without the fear of the metal bending, deforming or otherwise breaking in combat.”
“ What if cancer is not an ailment if one has a will powerful enough, and knows what do do. What if one using the right techniques could control it and use it to become immortal, or to grow into something else?”