“ 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”
“ After a long night of reveling and merriment celebrating their latest victory, one of the PCs awakens with his/her head shaved and a large ornate tattoo on top of their head. Tacky, yes but also a painstaking work of art that has left them with a headache to beat their hangover. The kicker? It is a huge symbol of the god of Evil, Assassins, the Drow, Munchkins, something really really offensive”
“ Weapons or equipment that is heavily relied on can be 'named'. Then the equipment begins to gain abilities beyond those of normal equipment. They might siphon off some of the experiances of their owners (1 to 5%) and level up on thier own. Could be an unintenitional way of creating artifacts. Ships could become sturdier or seem to just barely outrun the worse of a storm that would have surely sunk another vessle, swords could fumble less or resist dulling more, a farmers plow could turn stones aside easier. Anything that is depended on as much as an inividual can depend on as much as another individual could be 'named'.”