I like what we have so far, just to flesh things out, the inn owner sees how good they were in the bar room brawl and asks them to clear out the giant rat problem he is having in his cellar. Once there, they see that the rats are coming in from a hidden passage that leads to the dungeon.
A few tropes I would like to include:
- The place was built by a mad wizard for no discernible reason
- There are guys out the front charging entrance to the place. You have to pay money to get entry and explore for loot. Steve Jackson used this one a bit in the early days if I remember correctly. The idea of a dungeon of a mad wizard being a tourist attraction for adventurers is just so absurd I love it.
- A latrine that serve no purpose but to house an Ortyugh (sp?) it also strangely has lots of treasure in it. Other latrines have treasure but not the monster, who knows why.
- A messed up ecosystem with goblins living next door to harpies and rust monsters for no apparent reason.
- An absurdly powerful item, preferably a ring of wish or a Deck of Many Things that can completely break the game. It is not the object of the quest, just off in a side room for some reason.
- A door that takes 4 gems to open, one of each element, of course they are guarded in themed rooms for each element.
- Definitely a magic mouth riddle door, as we previously mentioned
- A chessboard room of course
- A mirror that changes alignment, or creates dopplegangers
- Mimics, but also rug monsters, stalagtite lurker things and a dark mantle pretending to be the roof.
- Potions of different colors, unlabeled with no way to tell what they do