Keeping Encounters Fresh

Do you remember the first time you encountered a troll without knowing what it was? The horror at realizing that nothing you were doing to it was sticking? The mad scramble to find damage that would stick? Pleading the with the GM for a clue?

Fast forward a few campaigns and suddenly when the party encounters a troll, the appropriate gear comes out. Fire and acid become the words of the day and the party mage is lambasted if they don't have fire spells.

How can you keep the thrill of discovery and the tension of encounters alive after many campaigns? Whether players intend to or not, previous knowledge comes into play, and that excitement is lost. I feel that what the players feel translates to their characters and can enhance their experience. So no matter how well the players can roleplay they will not have the experience that they once did.

So how can the GM help the players?

By changing monsters. Trolls don't have to be green in your world. Hell, trolls can have two heads in your world and mechanically function exactly the same. As far as game mechanics are concerned the description is meaningless, so have it be what you want. Make your Hill Giants look like Clay Golems, keep your players on their toes.

Give monsters meaningless abilities, non mechanical ability. Have one or two orcs in a fight constantly smoldering. Have a skeleton show up oozing black ichor that smokes when it hits the ground. Let your players believe that they are more than what they are and the entire tenor of the fight will change.

If you don't have the time, or aren't willing to invest the effort in redefining lots of monsters, there is another options. Look to expansion splat books or 3rd party supplements for additional monsters or templates.

My players have been playing for some time, the Monster Manual is fairly well known. This has also led me pull from Monster Manuals 2, 3, 4, and 5. My players are only familiar with what I've thrown at them so all of these books are valuable resources.