Wednesday, January 30, 2013

Mountains and Mole-Hills

I am going to try to get this one out really fast. Limited time here. Rob over at Bat in the Attic posted some long distance sighting rules. They are a great set of rules. The real genius behind them is the kind of linear rock paper scissors thing he has going on with the mountains, hills and plains with an assumed height for generic mountains and hills.

I wanted to offer a correction. The heights and distances presented are off by an order of magnitude for the mountains and in my opinion a little short for hills. If you go on the idea that the average height of a notable mountain peak is around 10,000ft (great peaks like Mt Ranier, and others land between 10k and 20k with legendary peaks like Everest and Denali topping out in the upper 20k's), and the United States and England both draw the "official" this is now a mountain line at 990ft and 2000ft respectively you see what I mean. You can see mountains from quite a distance on a clear day - getting into the 100's of miles.

So lets turn this into game stuff:
I have been thinking about mountains a bit in my game design efforts when it comes to travel and sighting. So this info is stored in my trivia banks an easily ready.  Humans start to experience altitude sickness at about 8000ft. Tree-line fluctuates around this depending on latitude an atmospheric conditions generally we could say that 7500ft is a good round ball park number. So I would assume that given navigating mountainous terrain is essentially a matter of finding your way through spurs, around mountains, along rivers and over saddles (the low arts between peaks) casual travelers will be at about 5000ft if they are in a mountain hex. 
Hills are a crazy beast. No one really knows when a hill starts being a mountain. There are all sorts of ways that use height to slope and distance around base. I like hills ending at 1000ft for game purposes. It allows us to say that most mountains are an order of magnitude higher than most hills. Just like when traveling through mountains, in hills you aim for the low areas rather than follow the ridge lines and go from peak to peak. So we can ballpark the height for casual travelers in hills at about 500ft. If you decide that hills go to 2000ft then you will obviously use 1000ft as the casual height.
I work on the 6mi per hex scale. So the hexes here are going to reflect that in my calculations.
Rob's note of about an hour to find a good sighting place is pretty accurate with my own hiking experience in hill like areas, but I would stretch this to 2 hours in mountains. On open area I would reduce it to 30 minutes and for swamps I would say you can only ever see into the next hex. If they want to strike out to tree line throw in an additional hour.  Breaking tree line is handy and generally offers wide unobstructed views. The same is true for peaks and I would say that gaining a summit allows you to see over the next 2 mountain hexes in mountains or hills.
Another point of note: Broken or overcast clouds are totally going to ruin your view from a mountain, but generally not hills.
If the mission of the party is to map large amounts of area they very well might want to climb the highest mountain. At this point they are climbing a specific mountain and are out of the scope and intent of this rules exercise.
Time Needed: Mountains: 2 hours (3 hours for tree line; 4 hours for peak)
Hills: 1 hour (2 hours for peak)
All other: 30 Minutes
Distance Sighted Over Lower Terrains: (counting for refraction: d~= 1.32 * Sqrt(h) where d is in miles and h in ft.)
Random Peak (10000ft): 22 hexes
Tree Line (often 7500ft): 19 hexes (may be high enough for altitude sickness, referees call)
Mountains (5000ft): 15 hexes
Hilltop(2000ft): 10 hexes
Hills/Hilltop(1000ft): 7 hexes
Hills(500ft): 5 hexes
Distance Sighted to Equal or Higher Terrain:
Mountains to Mountains: 1 hex
Mountain Peak to Mountains: 2 hexes
Hills to Mountains: 1 hex
Hills to Hills: 1 hex
Hilltop to Hills: 2 hexes

Broken or overcast clouds block mountain views to 1 hex, and may do the same for hill views.
The distance sighted over lower terrains is also the maximum distance that such a particular elevation can be seen. So a mountain can be seen fairly certainly 15 hexes away- but the foothills 10 hexes away won't be discerable (or only just so)  but any foot hills 5 hexes away would be visible but would block the view of those between 5 hexes and 15 hexes away.

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