I expect the City States of the Divine Dragons to be points of light in an otherwise dangerous world. Thinking along the lines of designing the world for adventure and to make the characters stand out in their eventual ability to move about freely. To that end, each city state should be surrounded by concentric regions that would present challenges suitable for parties of increasing level.

To that end, the regions should have random encounter tables of “hard” challenges for levels 2, 4, 6, 8, 10.

That means, travelling from one City State to the next means risking encounters for levels 2, 4, 6, 8, 10, 8, 6, 4, 2. This will let the players feel quite capable (including having mechanisms to say “yeah, you obliterate the lvl 2 wolf encounter, we’re not gonna worry about that one”), and also feel like “nobody else could do this” when they get to the lvl 10 encounters. Once they can handle lvl 10 encounters with relative ease, adventures should probably take them beyond the material plane anyway. 

But what about everyone else?

5e’s bounded accuracy is a boon in this kind of space, because it means that there is a reasonable safety in numbers. Large caravans can move through the regions and drive off even the most aggressive monstrosity that might try to challenge them. River passage might be particularly safe, but, expensive. 

So what does it take to send a message from one city state to another? (That’s what inspired this post, anyway!)

If there are people capable of casting spells who live in a town, with very rare exceptions, they cannot cast spells outside of their place of power, and their spells are capped at 4th level, generally — and those are expensive indeed. A 3rd level spell like Sending is a major working of magic and prohibitively expensive for common folk. I am now realizing that I really need to sit down and map out what it takes for non-adventurers to cast magic. 

So that leaves mainly Caravans and River Traders.

To me, this all means that the river & coastal towns will be quite caught up with news, since they can get updates with every passing boat, but the further inland a town is, the more lagged the news will be… but the more exciting a caravan will be!

And, every once in a while, there is the Centaurs on the Path of Seasons, a winding migratory path that winds its way around the continent, completing its circuit every year. One might get some news that way too.