Odhanan
Adventurer
For me, the "Old School" tag has much more to do with the presentation of the adventures and the kind of details that are emphasized within the module than its actual events or locations.
An old school module can have some plot, no plot at all, that's not what actually makes it "old school" for me. It has to do with short, to-the-point descriptions of locations and NPCs. It leaves a lot for the DM to adjudicate, to describe on his own. It provides a frame for adventuring, not the adventure itself. It doesn't present a "story", but paths/locations/rooms in which the actual adventure can happen. It's also more focussing on action (as opposed to events and things occuring out of camera). It sometimes has to do with threats that are real threats to the PCs, with confrontations against some impossible odds at times (demon lords, truly deadly traps, and so on).
It's more about the way the adventure is thought out, then written by the author and finally how the reader/DM perceives it.
An old school module can have some plot, no plot at all, that's not what actually makes it "old school" for me. It has to do with short, to-the-point descriptions of locations and NPCs. It leaves a lot for the DM to adjudicate, to describe on his own. It provides a frame for adventuring, not the adventure itself. It doesn't present a "story", but paths/locations/rooms in which the actual adventure can happen. It's also more focussing on action (as opposed to events and things occuring out of camera). It sometimes has to do with threats that are real threats to the PCs, with confrontations against some impossible odds at times (demon lords, truly deadly traps, and so on).
It's more about the way the adventure is thought out, then written by the author and finally how the reader/DM perceives it.