S3-Expedition to the Barrier Peaks.

[Porphyre]

As I understand it, S3 was originally a tournament convention module, and strongly tied to MA publication.
 
Now, has someone already played it, not just as a "one-shot" adventure, not as a "out-of genre experience" in an overall "vanilla fantasy" campaign, but as the starting point of whole campaign-change? 

[flightcommander]

I was really hoping somebody would chime in here and report that, YES! they did in fact use S3 as a sort of pivot-point in their campaign. I can only report that we played it pretty much straight up, with whatever characters folks decided to bring to the table, in our own vaguely (ie, barely) "Greyhawk-ish" play sessions. It was fun! The Mind Flayers were a big deal, as I recall, as it was our first encounter with them as players. I think trying to incorporate the psionics rules jack-knifed further adoption of the setting implications for my group, as they added complexity and silliness without adding anything else, and just slowed down the game. Also, we had already started playing 1st Ed Gamma World and the sensation of connecting the two didn't sit well somehow — we either wanted to play one or the other.

S3 is such a peculiar scenario that I'm sure everybody who's played or DM'd it has a unique and memorable experience of it — I think that's my fondest memory of this module! It was kind of a revelation to a kid who entered the hobby via The Hobbit and Holmes Basic. It's definitely (though obliquely) informed my scenario design ever since.

[bobjester0e]

The "module" is dense enough to be its own campaign bridging fantasy & science fiction and could do so without even stepping a toe into MA or GW systems.

Truthfully, I haven't read it since the mid-80's, although I thumbed through my originals once I picked up Goodman Games' Barrier Peaks coffee table 5e conversion version.