Some time ago, Jeff Rients posted something about running D&D with only the Fiend Folio as the monster manual. I don’t remember exactly how detailed he got with that, and haven’t been able to find the exact post (this? or this?) , but since I was looking over the Fiend Folio the other day, I started thinking about what the implied setting of the Fiend Folio might look like.
One thing that might stand out is that there are some knock-offs of standard monsters. Hoar foxes fill the niche of Winter wolves (though they are smaller, fewer HD, and not as evil), for example.
Another thing is that there are many references to standard races and monsters, so really you need to decide whether, say, Flinds require the reintroduction of Gnolls, Nilbogs require the presence of Goblins, the Norker entry allows in Hobgoblins, and so on. You could just ignore those references, or you could grandfather in the things that the FF listings assume. Either choice seems legitimate to me.
The first thought I had was how the options for PC races would look. There are no dwarves, no halflings, no elves other than the Drow, and no gnomes other than Svirfneblin. Drow elves do not seem appropriate for PCs due to their evil nature. Both dark elves and deep gnomes have so many inherent powers that you’d need to (ok: I’d want to…) introduce some kind of extra rules to ration them out as they gain levels, and that isn’t appealing to me either. Lastly, those races are supposed to be enigmatic, barely-known races of the underdark, and having them as PCs would undermine (hah!) any attempt to keep the underworld mysterious, IMO. Githzerai and Githyanki may have become available as player races in 2e/Spelljammer, but they too seem so alien and mysterious they’d be better left as monsters.
If you wanted to allow some of the FF monsters to be player races, there are not a lot of good-aligned humanoids. I think alignment might matter because in AD&D as it stands, the allowed player races were all good-aligned in the Monster Manual — with the exception of half-orcs, who are not given a separate entry in the MM. Come to think of it, though, most of the human listings are neutral, so probably neutrals are ok too.
That leaves us with a few oddball humanoids, like the Aarakocra, which were ported in as player races in the 2e book of humanoids, and are also good-aligned, though their power of flight seems like a potential headache. The Quaggoth could be a neat mock-Mok, for a Thundar inspired campaign. The Qullan, which seem to be a source for the Talislantian Thralls (or at least share a common ancestor), would be ok as a colorful (hah hah!) option, perhaps replacing Half-orcs, and maybe Sulks could replace Halflings.
I’d be tempted to consider Grimlocks as a possible player race too, because although they are evil, there were several attempts to stat them up for players — both a semi-official Dragon article (#265) and a much older zine I no longer have (it was a small fanzine, I gave it away and don’t even recall the title). The idea of blind berserker is just too fun to leave out of your campaign.
One last thing on the player side of world-building is deities and religion. If you stick to the deities presented in the Fiend Folio, you get a very dark fantasy indeed! Lolth, the Elemental Princes of Evil, and two Slaad demigods. Oh, you also get the Aleax, which the gods send to punish you for varying from your stated alignment. The Death dog, being descended from Cerberus, sort of implies that there could be Greco-Roman gods in the setting (and the Aleax, which also looks fairly Classical era, would be typical of the Greek gods’ screwing over mortals). Because Retrievers were designed by Demogorgon, I guess we have him too. The Sons of Kyuss mention an unnamed evil deity. The Eyes of Fear and Flame were created either by chaotic evil gods to destroy the lawful, or by neutral/lawful gods to test the lawful. The upshot, then, is that you better not look to the gods for hope or help in the Fiend Folio world. If they notice you at all, it will probably mean they send an Aleax after you, who will fight you and either take half your XP and all your stuff, or if you are lucky, take you out of the campaign for a year and a day. Fortunately, most of the things that look like undead in the book are either not turnable or not really undead, so you won’t miss having a cleric (unless you encounter 4-40 Nilbogs, which can only be hurt by healing spells!).
So I’m getting the sense that this Fiend Folio world is really dark.
Anyway let’s look at the monsters that look like they might be undead.
Turnable undead: Apparition, Coffer corpse, Huecuva, Penanggalan (flying head form), Poltergeist, Sheet ghoul, Sheet phantom, Son of Kyuss
Non-turnable undead: Death knight, Penanggalan (human form), Revenant, Skeleton warrior
Not actually undead & non-turnable: Adherer, Crypt thing, Eye of fear and flame, Gambado, Githyanki*, Necropidius, Vision, Yellow musk zombie
*Like the Meazel, the Githyanki are obviously based on the Iron Maiden mascot “Eddy”.
Only a minority are turnable, and most are turned as wights, wraiths, or specters, so your cleric has little chance.
All those non-turnable undead and psuedo-undead also remind me that the FF is sometimes criticized as consisting of a lot of screw-the-player gimmick monsters. While there are a good number of gimmicks, you have to admit the Monster Manual has plenty of those too (Ear seekers, Shriekers, Gas spores, Rot grubs, Rust monsters, Yellow mold, Brown mold, and so on and on!).
I guess we should also look at the giants and dragons, as those are staples of fantasy, and I admit they are a little underwhelming. The giants are not bad — at 12 and 14 HD, they are as tough as anything in the Monster Manual, and the Mountain giant certainly looks like a classic storybook giant. The Fog giant, with his surprise ability, looks deadly, though they should probably have the ability to generate fog too. The dragons, on the other hand, are maybe the weakest thing about the Fiend Folio world. Instead of being the benevolent spiritual beings of Chinese folklore, or the destructive forces of nature of Western folklore, they seem to be inscrutable spirits of nature — not necessarily hostile, but capricious and dangerous. Some demand tribute, some accept bribes, but none have much in the way of clear or useful motivation. They are all shades of neutral, and that makes them seem more like animals than dragons, despite their generally high intelligence. The trolls of the Fiend Folio are all pretty good though — in fact I like them more than standard D&D trolls. They are certainly more like Norse trolls, and the Ice trolls and Spirit trolls suggest they are more supernatural than standard D&D trolls.
So if I were to describe the world of the Fiend Folio, I think it suggests that monsters tend to be otherworldly — ethereal, elemental, or undead, or else they are beings from the underworld of dungeons and caverns. The animal-type monsters are mostly botched magical experiments like Gorrila-bears, or gigantic vermin like Giant Bats and Giant Hornets, or else super-predators like Babblers.
The humanoids are often alien (Kuo-toa, Firenewts) though some resemble the primitive or militaristic subhumans we find in the Monster Manual. So, it is certainly recognizable as D&D. It is just a little darker, a little wackier, and maybe a little more dangerous, since there are almost no “standard” low-level monsters that you can just fight (exceptions being things like Xvarts and Norkers, though the Norker’s high armor class makes them a real danger to first level PCs). For example, Quaggoths (HD 1+2) go berserk and fight to negative hp; Qullans (HD 2) have super-sharp swords that score bonuses to hit and damage (but of course the blades quickly lose this property when looted!)
Looking at the dungeon monster tables in the back of the book, all the “weak” monsters are thieves or ambushers like the Jermalaine, Mite, and Snyad. Humanoids like Bullywugs can make three attacks, or have boosted AC like the Norkers. And that is just the level I monsters. As you go to higher level charts, it seems that the FF monsters tend to have boosted AC, HD, or other powers, compared to their Monster Manual peers. However, I have to say that dungeons stocked according to the FF charts would be a lot less predictable than the standard DMG tables.
So — and this looks like my second or third attempt to wrap up, I always sucked at conclusions — so anyway, the Fiend Folio world looks like something it could be pretty fun to run. It would slightly crank up the weird and the deadly, and downplay clerics and demi-humans. The only thing I’d really miss are the original dragons and some of the staple, dare I say iconic monsters like orcs, beholders, and rust monsters. Instead, we’d have norkers, slaad, and disenchanters. Which is to say, the kid gloves would be off and the difficulty cranked up to Ultraviolence. Sounds like a plan!