Koewn's mention in last post's comments of OSR spell-point systems that give more recharge in the wilderness, because it's a more fantastical place than civilization, got me thinking. I agree with the general premise, that wilderness ought to be fantastical, and civilization ought not to be very fantastical (if nothing else, this helps keep the economics grounded). But giving more recharge in the wilderness than in civilization would throw the wilderness resource game very far from the B/X roots, which I think are mostly solid but need some elaboration.
Concurrently, thinking about wilderness as dungeon - we have dungeon levels, as a measure of both distance from the surface and of danger, but the danger of wilderness regions is not handled so clearly. In ACKS we have both the wilderness/borderlands/civilized distinction, and then terrain type also heavily influences number of lairs and encounter chance, and some terrain types are arguably more dangerous in practice due to differences in their random encounter tables.
So I'm thinking maybe we impose Wilderness Level, as a measure of danger, supernatural power, and expected treasure, in regions. Reorganize the wilderness encounter tables so that more dangerous creatures appear at higher numbers, and then switch from d12 to d6 + wilderness level. Maybe apply it as a modifier to encounter chance and number of lairs too (instead of having that be by terrain). So untamed plains are about as dangerous as untamed mountains, in terms of their inhabitants. And then you can have Tamed Mountains that are reasonably safe without having to recall the implicit rule in ACKS that causes encounter roll frequency to vary with civilizedness. Just make it explicit and simple by analogy with dungeon level.
Then, to link it to civilization, spellcasting resource management, and base construction, building and maintaining temples, wizard's towers, etc reduces wilderness level in the surrounding area (possibly at wilderness "room" or biome scale? Or temple per room plus shrine per hex?). These work by siphoning magic from the wilderness, which is inherently chaotic and dangerous, and laundering it through deities, rituals, etc, into a form which is not fundamentally inimical to human life, which can be safely used and controlled by spellcasters. Imposing a schema (mathematical or extraplanar for arcane or personified deity for divine) on the raw, schema-less magic of the wilderness limits what you can do with the magic, but it also limits what the magic can do to you. Human magic is legible; wild magic isn't. So regions of civilization are safe, sane, and stable because existing temples and guilds spend a lot of time and cash operating "heat sinks", and the total throughput of these heat sinks limits the total number / power of wizards and clerics available to civilization.
A couple of interesting things fall out of this:
This helps explain why barbarian/beastman hordes pillage temples; this returns the land to wilderness, by eliminating their protective influence. Also justifies centrality and necessity of religion in daily life.
Likewise, a temple which "appeases" a volcano operates by drawing off the wild magic which might cause eruption, spontaneous generation of fire elementals, etc.
If you're out in the wilderness and you're tapped out but you need one more fireball, go ahead, tap into the raw wilderness magic. What could possibly go wrong? Lycanthropy? Animal body parts? Extra head?
Elves - native to wilderness level 1 rather than wilderness level 0 like humans and hobbits (I dunno about dwarves yet). Better at wild magic use? Spellsinging from Heroic Fantasy is very much on theme; if wizard magic is like baroque and cleric magic is like gregorian chant, the elf is improvising jazz.
It's normally weird that lower HD beastmen have better witchdoctors and shamans (eg goblins get d6/d8 level spellcasters, but ogres only get like d4 level spellcasters). But if ogres are the product of a wilder and less schematic environment, then it makes sense that they don't really do spells (and instead rely on ambient raw magic to maintain 4HD) whereas weaker beastmen, more common right on the edge of human civilization, are exposed to more schematism and might have deities but less embodied magic to draw on.
I could see something like Vinge's zones of thought as a useful analogy- at low wilderness levels, your horse is animal sentience. With prolonged exposure to high wilderness levels, your horse becomes a fairy tale horse and might start talking.