A sickness is destroying the crops. A town, wishing to avoid past horrors, seeks out daring folk to try and stop this trouble at its source. Can they find who’s to blame?
A local Wizard, rumored to have lost his mind, like he has his hand, Has issued a Challenge and a prize for all. Simple-Enter his tower and find him to claim your prize.
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