Expand a campaign setting

[ClothedInVelvet]

Ok playground, I'm building a campaign setting in my mind. I'm very good at coming up with the concept, but terrible at writing it down or communicating it. So what I'm hoping you can do is help me tease it out.

What kinds of things need to be specified for a good campaign setting?

What things will affect the players/characters and what will make for a better gameplay experience? For example, I've got the districts laid out, but how helpful will it be to specify the order of shops on the street?

I know many of you have already created your own settings, and I've done some before, but it was half-baked and didn't have the detail that I wanted. So what kinds of advice do you have?

[sonofzeal]

Generally, I like to have a list of notable NPCs for any settlement the PCs are near, but most of the rest can be fudged. Overpreparing just means you're burdened down trying to dig out every little detail in your binder of notes, and the PCs will still manage to surprise you by recruiting Nameless City Guard #17 into their party.

This happened last game I was in; Dave was Fighter 6 and we were lvl 10-12, but through dint of us blinging him out and some pro luck on rolls, he managed to be more effective than most of us. It got to the point that the entire party basically agreed that Dave was the hero and we were all just sidekicks. Keep in mind that the DM didn't even have a name for him at the point where we basically kidnapped him, and understatted him, and let us run him for the most part. This wasn't a DMNPC.... this was just our group being nucking futz.

Point is, don't try to predict PC actions because it's impossible. Improvise, improvise, improvise, and only plan out the stuff that can't be improvised as well. I usually plan the NPCs and general social dynamics and intrigue, and the fights for the players. Everything else though? Total improv.