Watching Stranger Things the very 80s horror/sci-fi Netflix series last night gave me an idea. I won't be discussing a lot of plot detials here, but I will mention some setting/situation stuff, so the absolutely spoiler averse should beware...
So strange things are afoot in a small town, that seem to involve another dimension/universe whose walls have been breached by a nefarious research organization and D&D-playing kids investigating these goings. What if the other world was something more like a "realm of Dungeons & Dragons," as the Dungeon Master in the old cartoon used to say?
Somehow (psychic powers, I'm guessing, but maybe a device), a gaming group gets transported to this parallel realm that is a distorted mirror or their home town, filled with the trapping and set-dressing of setting-nebulous D&D. Like, geographically, where the nefarious corporations facility is, there's a mountain where evil creatures dwell. The sublevels beneath the facility are (of course) dungeons. The corporations video archive room might be a forbidden library, etc. The kids aren't transported into this realm to stay, like the D&D cartoon or Joel Rosenberg's Guardians of the Flame novels, but instead visit there in sessions and return to the regular mundane world at other times.
The kids are trying to solve a mystery of some sort in the real world. The forays into D&D fantasyland would need to serve this mystery somehow, allowing them to gain information or get access to places that they couldn't get to "in the real world." While the presentation would be different things would work pretty much the same as the Matrix/real world divide in the Matrix films.
You could run a campaign with two systems (or at least two settings) in tandem. The players would play kids in the real world 80s small town, but also kids playing D&D characters in a more conventional D&D game. The goal of adventuring in the D&D world would be to ultimately solve the mystery in the real world. Both worlds would be essentially mystery sandboxes.
2 hours ago