This is the same justification I give for the existence of Read-Aloud: rooms can be super fucking janky shaped, and it gets real slow when you're trying to come up with the right way to explain what your characters are seeing. I find that having text written out beforehand to convey the situation is supremely helpful in that regard.
Yeah, having a room description makes a
huge difference for immersion and keeping the game going smoothly. It doesn't necessarily have to be read-aloud, though. I tend to like read aloud because I've really honed my reading-aloud skill outside of DnD, so I am good at making the read-aloud sections sound very good. A well written short paragraph adds a lot. Bad, lengthy read-aloud fucking sucks though.
A really great alternative to read aloud are the style of room-description done in adventures like Hole in the Oak and Winter's daughter.
One measure of a good map is whether or not I can easily visualize how it would actually look in 3D (as that's typically how you're going to describe its dimensions to players both when they're approaching the structure itself and when navigating the rooms). I've seen some maps that look neat on paper but don't make any sense spatially or would just be confusing to explore in play (especially so if your players do their own mapping-- they have to be able to draw the damn thing).
Concerning the last one posted above: Not bad, you can see that it's a fortress built into the earth, with a main hallway leading east to a second large structure (I would probably have extended part of this one upward to reach the ground above, adding a third entrance to the dungeon), with crypts built into the walls on both levels. My only real issue with it is who in their right mind would build those triangular-ass rooms on the left? I know it's a fantasy game and all but some things just don't have any practical purpose even in elfland.
Yeah, having descriptions in the text of the rooms makes it considerably easier to map out/visualize for the players.
When I tried to run
The Darkness Beneath, I basically failed because I couldn't describe the rooms for shit in a way the players could map out or comprehend. Saying that the room is "irregularly shaped" really doesn't work for immersion. I also couldn't really comprehend the map myself because I didn't realize it is two separate levels, a side-view cut-away of the map would have made a huge difference. I ended up just putting the map on the table covered in shredded paper to make a 'fog of war.' I've picked up a few skills since then and I am going try running it again in the near future but man that was a tough session.
