The one time I ran adventure S4 The Lost Caverns of Tsojcanth it was a bit of a mess, yet it remains one of my favorite AD&D modules. Not because of the adventure, but because of the awesome insert, called simply Booklet 2: Monsters and Magical Items.
It's 32 pages long, the last 3 of which are specific information for the Lost Caverns. But the other 29 pages are chock full of awesome. The first eighteen pages contain the write-ups for thirty-odd new monsters. (All of which later appeared in the original Monster Manual II, so don't rush out to get this puppy just for the new critters.) Following the monsters are a few pages of magic items, including three nifty artifacts: Daoud's Wondrous Lanthorn, the Demonomicon of Iggwilv, and the Prison of Zagig. The Demonomicon contains several new higher level cleric and magic-user spells. One of these new spells, Henley's Digit of Disruption, was not reprinted in the original Unearthed Arcana tome, even though all the others were. After the spells and items are a brief essy on magical diagrams and a brief list of reputed properties of gems.
Taken together as a whole, the contents of Booklet 2 seem to be whispering a message into my ear. And that message is "make a campaign out of me". This almost random collection of monsters, magic items, spells, and miscellaneous bric-a-brac looks like just enough stuff for you to build a cute little setting. Give me this slim volume, a Player's Handbook, and a decent screen, and I could run a neat little mini-campaign without either the Dungeon Master's Guide or any further monster book. I'm not seriously suggesting that anyone do that. It would be throwing the baby out with the bathwater. Especially seeing as just last month Doc Rotwang! and I were mooning over the 1st edition DMG over at his blog.
Instead of being draconian about it and saying "I'm only using the stuff in this pamphlet", a fair more reasonable and sustainable approach would be to use the contents of Booklet 2 as the center pieces of a campaign that includes all the usual D&D stuff. So you could have orcs and dragons as needed, but the main threats of the campaign would be the derro and behirs or dracolisks from Booklet 2. Imagine a world where all the 'dragons' breathe acid AND petrify at a glance! That'll wake up some complacent dungeon hackers. (Incidentally, Jim Holloway draws the creepiest little derros I've ever seen.)
So this finally brings me around to the title of this blog post: Proscriptive Campaign Creation. The basic idea is to help yourself drill down on campaign creation through deliberate acts of omission. I find this approach extremely handy when dealing with kitchen sink settings or games with simply vast quatities of monsters and stuff. D&D being my prime example, of course.
By saying to yourself something like "Hey, this campaign is going to focus on this list of monsters" you'll achieve a tighter focus and a more memorable campaign. The big key is to pick memorable monsters across a wide spectrum of abilities, types, and power levels and to not paint yourself into a corner. When you've embarked on this type of exercise you need to remember that sometimes it's absolutely okay to occasionally break out the old standards like orcs and ogres. Hell, I'd be a bit sad to get through an entire campaign and never stab an orc at least once.
Generating the list of featured creatures can be the tough bit. I would absolutely love it if someone swiped the idea of using the S4 Booklet 2. Sign me up for any campaign where the Big Bads are the demon lords Baphomet, Fraz-Urb-Iuu, Graz'zt, and Kostchtchie. Remember Kostchtchie? He made the cover of Dragon once. That hammer of his may not be as powerful or have as much street cred as Mjolnir, but it's still pretty effin' cool.
Another awesome monster source for a proscriptive campaign would be the original Fiend Folio. Alot of people think of that book as the worst grab-bag of monsters TSR ever cranked out, but I think of it as a wonderful, glorious buffet of wacky critters. (You know, not many folks these days seem to remember that where we all saw the Githyanki for the first time.) Many of the monsters in the old Folio might be crap by today's standard of dungeon ecology and mechanical coherence, but if you used it as your sole monster book I guaran-damn-tee your players will never forget your campaign! For a modern D&D campaign I'd probably go off the beaten path for my monster source. My first pick would probably be Bastion Press's Minions, the 3.5 version of which is a PDF product called Complete Minions. Though I gotta say that it would be hard for me to put a Secret Eater into one of my games. They just look too much like Todd McFarlane's Spawn for me to take seriously.
In a game with lots of little shiny bits like D&D there are plenty of other things besides monsters that come in long grocery list quantities. Shining your light on just part of the list works with much of that other stuff as well. Going back to Booklet 2 for a moment, Daoud's Wondrous Lanthron, the Prison of Zagig and especially the Demonomicon of Iggwilv look like perfect Macguffin level artifacts around which you can build lengthy plot arcs.
The one thing I recommend DM's not trim is the list of character build options. I firmly believe it's the players' job to decide exactly what kind of freaks of nature they run. Don't let them roll over your campaign with some obscure ultrapowerful class or race from an oddball supplement, but give them a wide enough variety of nifty options to choose from and most players won't go that route.