The basic idea is God destroyed most of the world over a thousand years ago. The PCs live in a heavily populated city where no one goes adventuring because it's far too dangerous. They will be the first in over a hundred years. As far as anyone knows there is no civilization in the world beyond the city itself (just bad guys: orcs, goblins, monsters, etc.).
OK, but
by extension that would imply there's nobody very powerful in the city, which in turn means that the PC's will rapidly become nigh-unstoppable
in their home town. Personally, I'm seeing some sort of grand conspiracy: there actually
is a thriving civilisation
* out there
and the Powers That Be know it, but the city fathers are preventing anyone finding out (and coming back to tell the tale) for nefarious reasons Yet To Be Revealed...
If you want to bring a scenario like yours to life, you'll need to think carefully about stuff like "where's all the damn food
** coming from?" and "what do they use for money?" along with more game-mechanical questions like "in a closed economy with no adventurers, are the PC's going to have to make
all their own magical clobber, or what?". But I'm sure you know that
As plenty of people have offered their opinions of the classes you listed in general, I'll try and stay focussed on the campaign you've described.
Scout: Without PrC's, this class is a half-assed ranger/rogue with a wobbly niche, but it's
certainly not unbalancing. If you like it, what the hell... It makes sense that a civilisation forced to stay inside big stone walls due to the excessive scariness outside would have a cadre of dedicated, military-trained lookouts who specialise in threat intelligence and staying out of sight.
Warlock: Not going to break anybody's game (even with Hellfire Warlock/Legacy Champion shenanigans they only just keep up with blasty-focussed Sorcerors) but if you're down on infernal influences, you might want to re-flavour the class to be more generally fey-tasting or somesuch. In such an insular and population-dense environment - one, moreover, that's not at all familiar with adventurers and the eldritch - someone with a whiff of the brimstone about them is going to last maybe a week before being granted a forcible appointment with the nearest bonfire.
There's nothing like someone
slightly scary to get a cowardly mob baying for blood.
If you can side-step the diabolical/infernal origins and have
all your Warlocks derive from a more palatable heritage, I can see them playing a prominent role.
Beguiler: Hooray for you, Beguilers are great. They're balanced, flavourful and generally good times all around. Not only that, but they're a natural evolution of spellcasters in an all-urban, humanoid-only environment... They'll be
hell on legs in your City of Wusses though, be warned.
Dungeon Delver: Well, I don't know what the circumstances are that lead you to want to include it, but a Rogue-based PrC that specialises in spelunking - in a world where all the "civilised" inhabitants live in one big city they've been too scared to leave in a century - seems a little dissonant with the note you're trying to strike.
Master Specialist: Again, fair enough on the game balance front, but... Surely a culture that supports Wizards to the extent where they not only have specialists, but have a PrC for really
special specialists, can't be the same culture that's so wimpy nobody ever goes out for a picnic because of the Orcs, can it?
Here's the thing... Wizards require infrastructure, more than possibly any other class. They need ink and paper (or the local equivalent). They need torts, alembics, leibig condensers, lenses, prisms and other complicated glassware, along with the requisite twisty metal things to hold them. They need alchemical supplies: acids, alkalis, bizarre reagents, bits of animals, good-quality fuels (for a constant heat source) and goodness-knows what else. Which means, in turn, they either need to have the skills to make all of those things themselves, or they need (among others) blacksmiths, charcoal burners, pigment grinders, chandlers, dyers, tanners, glassblowers, miners and so on. Unless they research all of their spells (for which they presumably need books or other research material) they have to learn them from scrolls or other Wizards' spellbooks.
A lot of the stuff they'd need or want is not going to be required by the common people, or even the majority of the elite in the scenario you posit, so who's going to be selling it? I'm not saying you can't explain this away, but the traditional view of Wizard is very much high-culture: even if he lives in a remote tower on a mountain fastness, he's
getting his parchment and wand-making materials from somewhere. If the citizens of your postulated setting had even a significant minority of Wizards in the general populace, it's inconceivable that they couldn't have gained ground in the last 1,000 years. Hell, it's hard to imagine how any "high culture" could survive under such circumstances without expanding over that sort of time frame.
This is why I reckon there
must be power - real power - in the city somewhere, but it's kept out of the hands of the proletariat. This would
have to include such things as books of magic and the paraphernalia necessary to do things like brew potions or make fancy inks for spellbooks. After all, the underlying premise of D&D classes is that anyone with the right attitude and high enough stats can tell the laws of physics to get stuffed, so controlling the means by which people can do that is going to be necessary.
Goodness knows what happens to born Warlocks or Sorcerors, but I'm guessing it isn't pretty. Hmmm...
So unless your PC's are members of the ruling elite, it's hard to see them having access to the training, equipment, general backup infrastructure and peer recognition necessary to become a real Wizard, let alone a Master Specialist. The very name of the class implies that "there are Wizards, then there are Specialist Wizards... and then there are
Master Specialists!"
That's why I'm going to fly in the face of most of the advice here and say that if you're going to ban an arcane class, Wizard should probably be it. It's hard for anyone to prevent a Sorceror from slipping under the radar, and indeed it's possible that your culture would
encourage a certain number of people to become Warlocks, Sorcerors (of the blasty kind) and/or Warmages for defence purposes. Give them a high cultural status and/or lots of material privileges and you can
guarantee that anyone with the ability will come forward for "testing". These tests might well have a high casualty rate (as the "untrainables" - i.e. those with truly independent attitudes - are weeded out) but you can't make an omelette without breaking some spontaneous casters, eh?
Sure, they're powerful but they're a limited threat so long as you can keep them focussed on trivia like setting Orcs' trousers on fire with their minds instead of real world-shattering stuff. And of course, if you keep them indoctrinated and a close eye on their progress, you can always arrange for an honourable "death in the line of duty" if they go off the rails and learn spells or invocations that might threaten the status quo.
Wizards though... Wizards are trouble right out the box. They're driven to seek out arcane knowledge both new and ancient, and their potential repertoire of powers is limited only by the number of spellbooks they can hide. You'd never be sure.
Ultimate Magus: From your statement on the class, you already know these guys can drive your game off the rails. Plus, see above for my rationale for potentially removing prepared arcane casters (at least until your PC's get away from the city and discover "written-down magic" for the first time)... but on the other hand, what a cover this PrC would make for someone secretly bucking the system!
"I can't understand why Geldram isn't making better progress with his
magic missiles, my Lord: he seems talented enough and his neighbours tell me he's up all night practising..."
Holt Warden: Keep it as backup. The PC's will presumably encounter NPC's outside the city; maybe they find some sort of
sylvan hippy commune of wild elves deep in a forest, led by a Holt Warden.
Favored Soul: Again, not going to break the game. This civilisation of yours would probably be keeping a close eye on them (and Clerics) though. That's assuming there
are any Clerics out in the open.
God destroyed the world, you say? Now there's a reason to hold a grudge: I've never seen a scenario more suited to the emergence of Ur-Priests... although you'll
definitely want to tone down the spell progression. Maybe make it a 20-level base class; essentially just reflavoured Clerics who steal rather than beg their divine mojo?
WarMage: See above. An entire culture with a foxhole mentality is probably going to be devoting a significant proportion of its resources (wherever they come from) to defence. Far better to channel those with natural magical talent into limited-focus spontaneous casting useful for
blowing up people with green skin than into potentially unbounded areas of magic. Even if there's no conspiracy in the background of the city, your very-high-density society at large is going to be more comfortable with someone who's basically a walking siege engine than they are with someone who summons scary extraplanar monstrosities.
Godzilla.
Tokyo.
Yeah.
So what do you guys think should be included that are pretty close (power-wise/flavor-wise) to the basics? What definitely shouldn't?
There are plenty of other classes you could include that would contribute to the campaign flavour, but all the major niches are exploited by your current selection, so anything else is just gravy. In the quest to fulfill the utmost mechanical potential of a concept - and because of the HUGE numbers of PrC and other character options to help people do that - it's now pretty common to forget just how
well a shortlist of classes can fill pretty much any role you can imagine. They may not look that great when compared to the super-optimised combos that happen when every book is available, but if those other options just plain
don't exist, the core classes (with a few of the better-balanced alternatives thrown in) do just fine. If you feel something's lacking from the mix once you're in play, throw in an NPC for the party to learn from.
Like cooking, it's a damn sight easier to introduce new ingredients when you need them than it is to take them back out again if you don't like the results.
*
Quite possibly it's a civilisation of Giant Radioactive Mutant Cockroaches.
**
Metal, wood, clay, raw materials for textiles, earths for dyeing...
