8, 8, I forget what is for
But since it's the party that determines which gun gets fired, you need to prep a lot of props---many of which never see the light of day. The DM/designer just sets the stage, we don't write the story. When everything is strictly "functional" you can fall into the trap of imposing an expected result and it can feel very contrived. What's better (IMO) is just have a place loaded up with potential energy for the players to unleash in unexpected ways i.e. lots of loaded guns!The point is about concept economy. Like a short story, you don't have a loaded gun if it doesn't fire.
If you're going to do a city campaign the city has to justify itself through mechanics/theming or its just window dressing.
When you say "If you're going to do a city campaign...", I would stop you there because I (as DM) don't decide the nature of the campaign, my players choose what to explore and what directions to go...week after week, month and month, year after year. It's my responsibility to have plentiful dangling-fruit to tempt them, and interesting destinations to explore. As they turn over the various rocks of the world and poke around underneath, there are things big and small to notice and act upon. A small handful are connected (global), but most are just local phenomena.
"Concept economy" sounds like a lot of the D&D blog-advise circa. 2010 that was all about saving the DM effort. I personally don't buy into much of that. I think a proper DM works his arse off (and loves every minute of it)!
@Avi: I have seen that web-app before. It's pretty amazing! No doubt some day soon, AIs will be DM's (and maybe players) too. Have you all seen this about how computer algorithms (Dall-E) will soon be creating illustrations for us?
How would you imagine a painting of a robot with flowers growing out of it? "A happy robot with flowers growing out of his head, clouds in t...
Prompt: “Polymer clay dragons eating pizza in a boat” Computer-generated image (Dall-e 2 by OpenAI) For a several years now, computers have...
Unless of course, there are just certain aspects you personally find tedious...but then that's why they invented pre-generated adventures, eh? For me personally, I enjoy preparing the meal for my guests and spreading it out on the table to see what gets eaten. (...vs. fast food from the Drive-Thru?)