"It's a part of the universe that is about like combining outer space with heaven."
"Oh, cool. Okay. Got it."
Did you miss the part - which would not surprise me at all at this point - where I said that the GM and player can engage in a conversation through their questions? I'm not sure why, nor have you done a good job, in explaining how evocative language is required for communicating this sort of information. And when people don't know a term or thing, then you attempt to find a frame of reference that would potentially be more familiar for the person. Which is what normal people do in normal conversations about everything. I don't necessarily think the point is to get "anyone's heart aflutter" but to communicate the context and stakes in which their actions take place.
Hussar, my D&D group for the past few years was with four other people who had never played D&D before. I think that you underestimate, if not vastly exaggerate, the problem of communicating the basic ideas of the game. And we usually have a basic awareness of some cognitive contexts that our gaming group will likely have experienced.
So, your putative conversation is going to be nothing but modern references and not a single bit of "flowery language"? Githyanki are green space aliens, like Romulans only with swords?
I'm pretty sure that the four poeple, while they've never played D&D before, have been exposed to enough genre fiction and other media that they have a fair bit of context.
But, I've seen a lot of cases where, because the descriptions and language from the DM is so poor that everyone at the table has a different idea of what's going on and are working cross purposes because everyone's coming from completely different directions. I mean, the Astral Sea is outer space and heaven? So, it's filled with angels? Githyanki are good then right? After all, there's no evil in Heaven. Why are they attacking me? You said they were from heaven. I'm a good aligned character, they should be welcoming me with open arms and helping me.
I really don't think I'm underestimating anything. I've spent far, far too long dealing with non-native English speakers who do not share our culture to take any description for granted. Every single reference you've made presumes a native English speaker (or near native anyway) with a deep grounding in western Judeo-Christian culture. As soon as you lose that background, none of your allegorical explanations are going to work. Imagine teaching D&D to ten year olds and you're trying to reference Men In Black - a 20 year old movie they've likely never seen.
Look, I get that you don't feel the need to do this. I think it's very bad advice to tell DM's that no, they shouldn't pay attention to word craft. That the only thing that matters is the situation. This leads to very bland games, IMO, where it doesn't really matter what game you're actually playing. You could be playing a fantasy game or a supers game or a spy game or a horror game. Since none of the actual descriptions matter, and only the situation does, it's going to get really repetitive. "He's stealing your horse/car/hovercar/spaceship (circle the one that's appropriate for this game). What do you do?"
Without the language to back it up, what's the difference between a Call of Cthulu game and a D&D game? Situationally, there's virtually no difference - some evil baddy wants to eat your brains.
