Ever since I started the-thing-I-wrote-which-I-have-talked-about-at-length-but-which-I-have-no-special-desire-to-plug-here people have called it a "setting". Which is true, that's what it is, but I guess I never thought of it as a "setting", it's just "the place where I put my D&D ideas so Kimberly can decapitate them".
Anyway, I am looking forward to Sir Larkins upcoming rundown of the Forgotten Realms because everything he writes is readable and I can never get through setting books on my own. (Ok, not "never"--I got through Carcosa and I got through some Palladium stuff when I was 12 or whatever because I had nothing better to do.) Anyway, I have Literacy (English) at like 98%--so what's the problem?
The problem is most setting books are packed with extensive descriptions, in prose, of an RPG world. The world is either:
A) explicitly based on an existing literary, cinematic, televisual, etc. one, or
B) a technically original one.
If A, then that world is better described elsewhere. In the book or movie it came out of. I may not know how many miles Lankhmar is from Quarmaal, but most of what is in a Newhon sourcebook I already got in a much more entertaining form from the Newhon stories that I apparently liked so much that I bought an RPG based on them.
If B, then we have a different problem:
The world must be described. However: the RPG writer who writes about a world (no matter how awesome the setting itself is) is, almost by definition, worse at that than a writer who just writes stories for a living. Or at least writes things for a living that I wanna read.
I want to read maybe 0.001% of all genre fiction ever written by professional fiction writers with reputations in the field. Even assuming I likewise want to read 0.001% of genre fiction ever written in the form of a setting book by an RPG writer, that still probably adds up to maybe 2.1 people in the history of the medium, ever.
In other words: the setting book is full of original writing in a form that is not really the RPG writer's strong suit.
And if you're reading--as leisure--something you'd rather not read, you're not going to remember it. So if, as a GM, I actually need to remember that Squealhalla is the capital of Gullgorgica, I'm screwed.
A related problem is that the world is almost always full of concrete setting details which are basically re-skinned and re-arranged versions of things in pre-existing fact or fiction. Like the Holy Grail becomes the Sorcerer's Sphere and there's a faux-England and a faux-Germany and a Tolkienian forest, etc. These things are on purpose and done for reasons I can basically get behind, but the writers then have to waste a lot of wind talking about Great Cataclysms and fuel shortages instead of going, basically "Ok, you saw Mad Max, right? Mutants Down Under is like that, only with mutant kangaroos carrying uzis, ok?" or telling you the comparative population densities of Ilthbone vs. Harnmarr or that the war between the Skorks and the Guelves lasted 1300 years.
This is when I start to nod off. Yes, I'm sure Oerth is a fantastic place, but it's not because the great marsh gives rise to Mikar River east of the Grandwood Forest or because the Lorridges are found at the northern end of the Lortmil Mountains--it's because it has beholders in it.
So how should it go? I think if you want to give the world a setting, don't tell us, show us. RPG writers are good at writing rules--rules that simulate genres--so give us the setting in the form of rules (and monsters and items and all that) and nothing else.
Rather than describe how the Clanward Barrens are different than the Skarrblown Marches, just do this:
Random Encounter table:
1-2 Wild dogs
3-4 Stone ghosts
5-6 Claw merchant
1-3 Wild dogs (hungry, 1/2 hp)
5 Abandoned Claw Merchant Cart
6 No encounter
7 Eerie rustling sound
8 Bone vulture
10 Dead wild dog
Want history? Want flavor? Nothing in all of World of Greyhawk beats this sentence:
Relic: Eye of Vecna
Seldom is the name of Vecna spoken except in hushed voice, and never within hearing of strangers, for legends say that the phantom of this once supreme lich still roams the earth...(and now some rules about the Eye).
i.e. Build the fiction out of the tools you give us to run it, rather than worrying about describing each place and then telling us the rules that re-iterate what you already told us in encyclopedia-entry form.
That's how Carcosa does it--character classes, new items, spells, monsters--no big blocks of background info. The closest thing to a traditional travel guide is short hex-by-hex descriptions of points of interest--but even these are done in the form of usable game info. You have to piece it together--yet you could never say that setting wasn't described.
During a game, a GM puts his or her art into the ideas and into making the rules compliment and expand those ideas, not into prose descriptions of interchangeable mundanities. Why not have the setting description do the same thing?
All anybody wants to know about your setting is:
-How is it different from every other setting in the genre? and
-What rules did you come up with to make that happen?
If you are writing a commercial product then, ok, you can write an introduction--for the newbies. Otherwise: Give us a map, give us a picture or two, and give us the rest of the setting in the rules. Trust us, we will read the rules, that's why we bought the book.
Let's try it...
We can see how well this works in the comments. I put a table, you fill it in with data matching the last place the PCs were in your game. Let's see if we can tell these settings apart..
What's Chewing On That Carcass? Table For The Last NonDungeon Place Your PCs Were...(roll d6)
36 minutes ago