delericho
Legend
One interesting thing is how Sunless Citadel occasionally is mentioned as a classic. SC is a pretty decent adventure but nothing out of the ordinary. However, since SC was the first adventure in the 3E line it gets a mention anyway. I think people wish SC was great even though it wasn't (please feel free to disagree).
Okay.
The reason "Sunless Citadel" is a great adventure is not because it's anything out of the ordinary, or because of the stunning plot, or excellent characterisation, or anything else. In fact, it's precisely because it is ordinary.
"Sunless Citadel" encapsulated a large part of the iconic D&D experience in a very neat package. It's a competent (if not exceptional) dungeon crawl, featuring nasty monsters, dangerous traps, and treasures to be found. It even manages to cram in opportunities for roleplaying (Meepo, and that gnome), and interesting choices (do the PCs ally with the goblins? The kobolds? Both? Neither?).
It's certainly not a perfect adventure. And it's almost certainly not an adventure that I'd run for experienced players.
However, if someone needed a first-level adventure to run for new players as an introduction to the game, I would recommend it without hesitation. If for no other reason than that I ran it for new players as an introduction to the game, and they loved it.