In particular, my game is set in the Oligarchies in the Mountains of the Moon. In real terms, this is a fantasy counterpart of Nepal, with several powerful city-states ruled by immensely wealthy elite with a very casual view to the lives and sufferings of their less-wealthy peons. Yetis and yaks abound.
My players have so far traveled between two major cities, passing from one major river valley into another over a well-traveled trail through an otherwise-intimidating and labyrinthine mountain range.
|My players like calling sessions "episodes"|
The following is an unscientific thinking-aloud about mountains and their nature.
If you look at Nepal or any other mountainous country, there are, unsurprisingly, lots of mountains. Correspondingly there are valleys. Shocking, I know. If you look at a map which shows mountains in any detail - the kind with lots of lines representing 10s or 100s of meters in altitude - you see that mountains, valleys, and their interrelation are chaotic and fascinating.
|All folds and bumps like a crumpled piece of paper|
Most ridges end one of two ways:
(1) they taper to a nub, getting narrower and shorter, becoming the vertical line of a capital T to the horizontal bar of another valley - intersecting with a nudge that makes rivers do their squiggly U-bends.
(2) they don't actually end, they just curve around, capping off the valley and coming back down the other side as the valley's opposite perimeter.
|The ends of mountain ridges are like proud ramparts slipping sadly into the sea|
|So really when you think about it, valleys only end one of one ways - this end of the valley is just the middle|
When you look on those maps I mentioned earlier, you realise that this is how all ridges work - they form loops that run up against each other, a fractal of larger and larger valleys.
The general pattern is - the higher up the chain of larger loops (or "horseshoes" if you want to be more accurate) the larger the ridge and the higher the mountain. Almost like each smaller valley contributes its mass to a larger whole.
|All of the largest mountains in this picture are obscured but they're on the border beneath the Orange and Light Blue lines - you can see some of them on the Pink/Orange/Light Blue junction and another on the Orange/Light Blue/Yellow junction.|
The valleys in my game must therefore exist within such fractals. Although my players crossed from the Valley of the Hand to the Valley of the Warrior, in actuality those 'valleys' are comprised of a main river valley bristling with adjacent sub-valleys, each with its own tributary rivulet, each contributing the the ridge-horseshoe fractal building up into larger mountain ridges.
The Oligarchies are not flat. When my players have been following the trails from A to B to C, I have described as best I can the mountainous terrain and such. But actually I think this is something that could do with more proactive scrutiny.
If my game was set in generic fantasyland - a sort of pastoral English Midlands - it wouldn't really matter how fastidious one tracked location and terrain features, describing with pinpoint accuracy and respect to the canon of established descriptive precedent. You could describe a hill or forest or Stonehenge just for the sheer sake of having something interesting to put in the horizon, to paint the mental picture, and if the players decided they wanted to check it out, that they wanted to make concrete its existence in their story, bam, surreptitiously add it to the map, make a note. It changes nothing. It doesn't "break" the map. The rivers and roads are not irrevocably fucked because you added and extra grassy bump.
But in a landscape like Nepal roads and rivers go certain ways for very specific reasons. The road goes over the mountains at this point because there is a pass. There is a pass because that is the lowest, easiest-to-get-to point through this ridge. You can't just decide to skip the pass and cross the ridge a mile up ahead - certainly not with wagons and animals. That turns from "travelling" to "willful mountaineering", which when I word it like that sounds like a misdemeanor.
A big part of verisimilitude is consistency
If I just describe "walking through a valley" or "climbing over a pass" or "in the shadow of a great big mountain" just for the sake of saying fancy words, I have created irrefutable, immovable implications about a great deal of the local landscape that "hill" and "forest" in Englandia simply does not.
Saying there is a pass at point A means that everything either side of it is going to be a mountain ridge, probably with high points that would be known to the locals as named mountains. The land either side of this pass/ridge will be two valleys, each with a stream in them at least.
In mountainous land, all these systems - mountains, ridges, valleys, rivers, passes - are HIGHLY concentrated over small spaces and HIGHLY interconnected. If I said "oh, you pass a river heading south" - boom - now west and east are ridges, north is too and probably a great big mountain is up there also. If my players decided to get in a boat and follow this casually-invented river south, I've got to figure out where it goes, because wherever I put the course of this river, everything in a couple-mile radius around it will be obliterated and replaced with the corresponding ridges, cwms, scree hills, peaks and glaciers that come with the bargain.
And that's not even getting into how the hell you make traversing this environment exciting and flavourful for the players...