Based on comments on Tales From My D&D Campaign videos, it seems that one of the big attractions for a lot of people is the “size” and “richness” of the world and it’s history. Which makes it even more ridiculous that the setting doesn’t have a proper name beyond the placeholder “KT World”, but that’s another story…
Now, from the beginning, before the first session was ever played, I had a pretty good base for the setting - lands and peoples, conflicts of the past and present, myths and legends both large and small scale, laid out by my timeline (as described in my setting Timeline-making video). As the players shared their character concepts, and even more we played, the world grew, based on the additions they had made (including The Organization, the Hand of Sirius, a lot of Vistria, and the history of the war leading up to the creation of The Peacebond). In a custom (aka homebrew) setting, there is a constant interplay, where you take the elements added through roleplay, and the bits and pieces put in to serve the current adventures, and combine that with what already exists - you see connections that could exist, “wouldn’t it be awesome if…”, and you make pieces fit together, or you take a dead-end branch of lore and expand from it - adding leaves, which may themselves connect back to other bit, or sprout new leaves of their own. You have to remember that the things that you add don’t need to matter right now - they might never matter, and that’s okay - all they need to do is to make sense in your world, and your world becomes bigger.
So when the first TDDC videos went up, I think viewers could already feel that this was a big world that existed before the heroes - a place where things were going on out of sight, regardless of what the players did, without taking anything away from their own growing story.
Now, I'm not the best "community manager"-type of youtuber, because I am just too introverted (or at least that's my excuse). I’m the kind of person who likes my friends and family, enjoys spending time with them, but who doesn’t actually miss them when they aren’t around. Is that even a kind of person? Sometimes I wonder, but that’s me.
The one thing I do well (at least with the current size of my youtube channel) is that I answer the majority of questions users ask in the comments (even if sometimes the answer is “I can’t answer that”. But I really enjoy answering questions about the world, because when I can answer something without spoilers, there are two main possibilities: Either I get to reveal something about the setting that they may have missed, or which wasn’t in the videos, but it’s something I had thought about, and I like to share that… OR, the very question itself causes me to think about some new aspect, or add more depth to some vague, tiny part of the lore, and in doing so I am expanding the world that much more.
Creativity doesn’t happen in a vacuum. You need to have seen or heard or felt things around which to imagine and built. Each of us hopefully spends their life building a repertoire of things which, whether you remember them explicitly or not, inform your ability to create new (or at least, new to you) ideas. If you enjoy writing and creating, like I do, you can probably go pretty far based mainly on this internal well of themes and concepts, plots and characters, scenes and music and the emotions they instill in you. But one truism which I frequently repeat is:
It is always easier to improve something that exists, than to make something new.
This is why proofreading is important, but especially proofreading by somebody else. It’s why a good editor makes books or scripts better. It’s why $100 million dollar movies come out with some huge glaring flaw that you instantly see - because people who were further from the project (with a more outsider point of view) didn’t get a crack at that script at an earlier enough stage to fix it, or maybe somebody was too attached to their creative vision and couldn’t see the improvement. It’s why the Star Wars prequels, when nobody could tell Lucas what to do, were a mess, even though Empire Strikes Back was awesome - it appears to be largely Lucas ideas too, but other people had strong hands in shaping and refining the script, honing it into something great.
I’m not going to say that a solo act can do this as well as a great writing duo or trio (wtb a great writing-partner, seriously), but if you can get more points of view, it can really help. And in something as big (and relatively fuzzy) as building a world, rather than a single tight story, you can just keep adding and adding, rarely needing to subtract - every question becomes a great exercise in the improv-like art of “yes, and…”
So most of the time, when I’m asked a TDDC world or history question to which I don’t know the answer, or where my answer would be flimsy or lacking, it gets me thinking, and I very frequently come up with some great new history to add to the world.
Just as an example, I recently mentioned “the Black Sand” in an Extras video (the videos where I give more explanations or background on things), and a couple people were surprised because they had missed or forgotten in a previous video (years ago) I explained that this particular patch of black sand encountered by our heroes was effectively a residue of the ascension of the God Vecna. Not his ascension to be a god - he was always a god. But his ascension as he left the rest of the world behind to devote himself entirely to the Astral Sea, planning to conquer the Source of All Magic, which would let him rule the universe forever (spoilers, he didn’t succeed - at least, not yet).
Looking up the answer for these commenters, so I could link to it, I saw the old Vecna bit, and it got me thinking about what Vecna, God of Lies and Secrets and the creator of the Undead in my setting - contemplating what he was like before he ascended:
Some legends of make the mistake of portraying the Vecna as not having a physical form. The truth is that he had a real body, but as the God of Secrets, he was entirely silent and invisible - essentially undetectable. Scholars who know this debate whether other creatures could physically pass through Vecna's body, or whether other gods could sense his presence under certain circumstances, like when he was close - and wise people disagree on whether or not you could hear Vecna if he willed it so; some say that he could never be sensed, in any way, and it was for that reason that he created the Cloak and Mask which he wore when communicating with other beings. The Cloak was matte black (so-black-it-looks-two-dimensional-black), but that made it stand out against any background, even at night - and the Mask of Vecna was dark grey, with no eyes, but a broad white smile, and that is how he would appear to his closest minions, as he revealed to them the tiny corner of his plans which they needed to know.
Just like that, the world has grown. Does the appearance of Vecna make any difference to anything that will ever happen in the campaign? Probably not. He doesn’t even bother with this planet anymore. But it’s cool in its own right, and beyond that - we just added two potentially powerful artifacts to the world… and I know exactly who has one of them.
Anyway, ideas build on one another, and that’s how you grow your world - or at least, that’s why I enjoy answering novel questions that people have about my D&D world.