Now I'm sure plenty of us on here have seen Stranger Things recently (honestly I'm surprised I haven't seen a question like this yet) and it's whole premise about the Vale of Shadows has me intrigued. For those who haven't seen it or don't know, look here!
Based off of an earlier question of mine (here) I'd like to know what we currently know about the Vale of Shadows (or whatever it is actually called, as through some research, people have been calling it various different things). Are there any official sources that describe a plane similar to the Vale of Shadows and a little more specifically, what monsters live on that plane?
Ideally the focus would be on 5th Edition but I'll accept any information available as I'm sure the premise of the plane can easily be converted.
Best Answer
We know nothing “D&D official” about the Vale of Shadows, because it's not an official D&D place. It was made up for the show. It's normal for real DMs to create unique worlds for their groups to adventure in (the 5th edition DMG even says that the official D&D settings and planes are only suggestions that a DM could use), and that's all that the Vale of Shadows is: a place made up by the DM in the show that's tailor-made for the campaign they want (er, the script writers wanted to portray him wanting) to run.
Yes, the article speculates that if you squint at it you can sorta imagine that it's supposed to be the Shadowfell or something like it, but it's a stretch to start with. The more obvious answer of “it's made up” is far less of a stretch. Even if it's inspired by the Shadowfell, it's going to be different enough to become unrelated, because of inconvenient legal reasons…
The “it's made up” resolution is also supported by a simple practical point: they likely aren't paying Hasbro dumptrucks of money for the right to use D&D Intellectual Property in the show. The concept of Demogorgon, by comparison, is not owned by Hasbro, nor are troglodytes — and notice that the kids' dialogue carefully avoids describing any details about troglodytes or Demogorgon that would uniquely describe the D&D version of those concepts (hence why that Geek and Sundry article explaining what the show implies to D&D players needed to be written). Everything about D&D in the show is going to be implied by common words or un-owned names or new made-up names, and the dialogue carefully tailored to not let any of it uniquely match anything owned by Hasbro.