Outdoor Survival Map

[keith418]

How many square miles does this map cover? I'm confused. One description puts it at 31,500 square miles:

initiativeone.blogspot.com/2013/04/on-od-setting.html

Another source puts the total at 13,200.

oldschoolfrp.tumblr.com/post/55183481246/map-board-from-outdoor-survival-avalon-hill

[waysoftheearth]

I can't recall how big each hex is supposed to be in Outdoor Survival, but I do remember that there are 238 hexes in each of six section of the board, so there are 1,428 hexes altogether (or there abouts).

If memory serves, U&WA specifies that each hex should be 5 miles across.

If that's so, then the approximate area of each hex is ~21.65 square miles.

1,428 hexes x 21.65 sq miles = 30,916 sq miles.

[keith418]

Thanks, this makes sense.

[cadriel]

Yeah, I did an approximation by figuring the rough number of across each way and using that to determine the overall area of the map, rather than trying to find the area of the total number of hexes, which isn't completely accurate since hexes don't conform to the edges of a square map. But 30-31K square miles is approximately right as per OD&D.

[waysoftheearth]

I've been thinking about the Outdoor Survival map more and more lately.

U&WA advises us:

The terrain beyond the immediate surroundings of the dungeon area should be unknown to all but the referee. Off-hand adventures in the wilderness are made on the OUTDOOR SURVIVAL playing board (explained below). Exploratory journies, such as expeditions to find land suitable for a castle or in search of some legendary treasure are handled in an entirely different manner.

OUTDOOR SURVIVAL has a playing board perfect for general adventures. Catch basins are castles, buildings are towns, and the balance of the terrain is as indicated.

(p15)

And then on the following page:

When players venture into this area they should have a blank hexagon map, and as they move over each hex the referee will inform them as to what kind of terrain is in that hex.

(p16)

But how should the referee determine what will be in each hex?

One possibility is to draw a whole (or sufficiently whole) map of the world in advance. This might be an enjoyable activity -- or a barrier to getting on with the game -- depending on the referee.

Another possibility is to generate a hex map randomly, on demand.


If you want to try the latter but you'd still like your map to bear some vague resemblance to the original Outdoor Survival map, then you're going to need to know a lot more about OS's map than just the land area it covers.  You'll need to know how frequently each type of terrain occurs, how frequently each type of feature occurs, and how likely these are to co-occur, and so on.  In short, it would be neat if some bunny would go to the trouble of counting every hex and feature on the OS map and tabulate the results for us.


Turns out I'm that bunny.


Here are the numbers...


OUTDOOR SURVIVAL HEXES

Hex Type	Count	Frequency
Open	624	0.433
Wood	399	0.277
Mountain	254	0.176
Desert	118	0.082
Swamp	46	0.032
TOTAL	1441

So, if you want a random hex to teleport into from "somewhere else" (anywhere except an adjacent hex), then you could get pretty dang close to Outdoor Survival's terrain frequency with this:

2d6	Terrain Type
2	Desert
3	Desert
4	Open
5	Open
6	Wood
7	Mountain
8	Wood
9	Open
10	Open
11	Open
12	Swamp

That's nice, but you'll rarely be teleporting into a perfectly random hex.  Most of the time you're already in a hex of a known terrain type, and you want to determine the terrain type of an adjacent hex (or hexes).

In this case, it shouldn't be a perfectly random hex; the terrain type of an adjacent hex should be influenced by the terrain type of hex you are already in.  This is because the terrain types are "clumped" together on the Outdoor Survival map (like most other maps).

So, I also counted the frequency with which adjoining terrain types occur for every hex.  Which is:

	Num of	Num of		Num of	Edges	Touching	Type
Type	Hexes	Edges	Void*	Open	Wood	Mountain	Desert	Swamp
Open	624	3744	224	2675	429	373	24	19
Wood	399	2394	69	429	1735	107	0	54
Mountain	254	1524	7	373	112	930	100	2
Desert	118	708	12	24	0	100	572	0
Swamp	46	276	0	19	47	2	0	208
Total	1441	8646	312	3520	2323	1512	696	283

* edge of Outdoor Survival board. 

Which translates to the following frequencies:

If I'm in a	Then how	Likely	Are these	Terrain	Types?
Hex of Type	Open	Wood	Mountain	Desert	Swamp
Open	.76	.12	.11	.01	.01
Wood	.18	.75	.05	0	.02
Mountain	.25	.07	.61	.07	0
Desert	.03	0	.14	.82	0
Swamp	.07	.17	.01	0	.75

So, for example, if I'm already standing in a wood hex, then it's 75% likely that any adjacent, unknown hex would also be a wood hex, 18% likely it would be an open hex, 5% likely it would be a mountain hex, and 2% likely it would be a swamp hex.

These frequencies can be also be converted pretty accurately to a 2d6 based random hex table, as follows:

		I'm	Standing	In...
2d6	Open	Wood	Mountain	Desert	Swamp
2	Desert	Open	Open	Open	Mountain
3	Open	Mountain	Open	Mountain	Swamp
4	Open	Wood	Desert	Mountain	Swamp
5	Mountain	Wood	Mountain	Desert	Swamp
6	Open	Wood	Mountain	Desert	Swamp
7	Open	Open	Open	Desert	Wood
8	Open	Wood	Mountain	Desert	Swamp
9	Wood	Wood	Mountain	Desert	Swamp
10	Open	Wood	Wood	Desert	Swamp
11	Open	Wood	Mountain	Desert	Open
12	Swamp	Swamp	Mountain	Open	Open

The ref should roll separately for each unknown hex that is adjacent to the currently occupied, known hex. This will generate terrain type frequencies very similar to those seen on the Outdoor Survival map.


Of course, hexes on the Outdoor Survival map can also include features such as towns (bases), strongholds (basins), fords, lairs* (animals), and of course trails and rivers. These occur as follows: 

	Open	Wood	Mountain	Desert	Swamp
River	63	13			10
River+Lair	1	1
River+Stronghold		1
Trail		17	11		7
Trail+Lair		4	1
Trail+Stronghold		2	5		1
Trail+Lair+Stronghold			1
Lair	8	5	1
Stronghold		4	7
Town	7	1
Stronghold+Lair		2	2
River+Ford	13
River+Ford+Lair	1
River+Town	1
SUM	94	50	28	0	18
Frequency	.151	.125	.11	0	.391

Frequency is the proportion of hexes of each terrain type that have at least one feature in them.

* Outdoor Survival uses the occurrence of animals to represent "food". U&WA states these are "as indicated" but in a D&D world I think it's fair to presume animals are instead "monsters", and that these occur in "lairs".  You might want to call them "dungeons" instead of "lairs".  That's up to you.

It is apparent from the above that features can occur in combination.  That is, a single hex can contain more than one feature.  Outdoor Survival itself does not include example of every possible combination, but you might want to be a bit more flexible.  If so, you should roll for each feature separately, like this:

	p(	feature	) in Hex	of	Type
Type	Open	Wood	Mountain	Desert	Swamp
River	.128	.039			.217
Trail		.058	.071		.174
Town	.013	.003
Lair	.017	.031	.02
Stronghold		.023	.06		.022
Ford*	.023

* Only roll for a ford if a river is present.


Of course, it's all a bit long-winded to check seperately for each of six features in every single hex.  What about a single table that rolls it all up into one?

Here it is:

	d%	Chance	of Feature	in Hex	Type
Feature(s)	Open	Wood	Mountain	Desert	Swamp
River	1-10	1-4			1-22
River+Lair	11	5
River+Stronghold		6
Trail		7-11	1-5		23-37
Trail+Lair		12	6
Trail+Stronghold		13	7-8		38-40
Trail+Lair+Stronghold			9
Lair	12	14-15	10
Stronghold		16	11-13
Town	13-14	17
Stronghold+Lair		18	14
River+Ford	15-16
River+Ford+Lair	17
River+Town	18
None	19-00	19-00	15-00	1-00	41-00

This table exaggerates the likelihood of the very unlikely feature combinations by <1%.  If you wanted to be truer to Outdoor Survival you could use a d1000 instead.



So, there we have it.



I have messed about with this a bit, and I have noticed that linear features (rivers and trails) will require some "referee oversight", because these should occur in a connected series rather than at random.  The referee can allow for this by adding an adjoining trail or river automatically, rather than dicing for these, should one be necessary for the feature to continue (i.e., all other adjoining hexes have been rolled without one occurring).

The other issue is that Outdoor Survival omits coast altogether, so there is no possibility of oceans occurring with the above tables, despite U&WA having a section dedicated to "Naval Combat".  I am working on another set of tables that include coast and waterbourne hexes in addition, but these are not really to do with Outdoor Survival so I won't add them here.

Enjoy



 

[Finarvyn]

Ways, you are the "caller of the show!"

Not only are your results awesome, but the way you explained it step-by-step is awesome. I'm stealing those charts!

[waysoftheearth]

Aug 2, 2013 7:28:01 GMT -6 Finarvyn said:

I'm stealing those charts!

It's not stealing when I'm giving them away

Glad to hear you might use it!

[dizzysaxophone]

Yeah that was pretty freaking sweet! I shall definitely be using this soon!

[kent]

Aug 2, 2013 6:49:06 GMT -6 waysoftheearth said:

That's nice, but you'll rarely be teleporting into a perfectly random hex.  Most of the time you're already in a hex of a known terrain type, and you want to determine the terrain type of an adjacent hex (or hexes).

In this case, it shouldn't be a perfectly random hex; the terrain type of an adjacent hex should be influenced by the terrain type of hex you are already in.  This is because the terrain types are "clumped" together on the Outdoor Survival map (like most other maps).

So, I also counted the frequency with which adjoining terrain types occur for every hex.

That's clever, I like it.

I think the frequencies should be perfect for travel which is random in nature such as searching but when travelling in a straight line from A to B the incidence of change would be higher and this is because similar terrain types are clustered in two dimensions.

[inkmeister]

Ways, incredibly awesome work, as always. Thanks!

[waysoftheearth]

Aug 2, 2013 9:22:05 GMT -6 kent said:

I think the frequencies should be perfect for travel which is random in nature such as searching but when travelling in a straight line from A to B the incidence of change would be higher and this is because similar terrain types are clustered in two dimensions.

I thought about that too, but it's not an easy problem.

Some terrain clumps are long but narrow, so travelling in the long direction would actually result in less frequent change, while travelling in the narrow direction would (as you point out) result in more frequent change. Other terrain clumps are approximately circular, and these would not exhibit this difference.

I think the "correct" way to model it would be to add tables for random terrain types where two, three, four, or five of the neighboring hexes are known. This would give you the most accurate representation, but would likely suffer for being that much more complicated to use. I.e., instead of one table for random hex determination, there would dozens of them, and the ref would have to find the correct table to use on a per hex basis.

I'll just stick with the approximation generated by a single table until someone can come up with a better way

[kent]

Aug 3, 2013 4:50:32 GMT -6 waysoftheearth said:

Aug 2, 2013 9:22:05 GMT -6 kent said:

I think the frequencies should be perfect for travel which is random in nature such as searching but when travelling in a straight line from A to B the incidence of change would be higher and this is because similar terrain types are clustered in two dimensions.

I thought about that too, but it's not an easy problem.

No it's not simple.

Aug 3, 2013 4:50:32 GMT -6 waysoftheearth said:

Other terrain clumps are approximately circular, and these would not exhibit this difference.

In fact it was the general vaguely circular terrain that I had in mind.

The way to see it is to imagine a vaguely circular terrain type and pick any starting point inside. Then consider, one at a time, every single hex of new terrain at the boundary and imagine the starting hex and the end hex are joined by the two path methods, 1) A straight line of hexes (as straight as possible), and, 2) A path where the traveller walks out of a random edge each time. They both start and end in the same hexes but the second path will be longer, it can never be shorter.

Therefore depending on the mode of movement, straightline A-B travel, or random searching, the traveller will cross different terrain types at different rates.

It is a question of diminishing returns to keep honing a model though and I think what you have done will work well. It would be interesting to see a brand new survival board.

[owlorbs]

So awesome.

All we need now is a random online generator so we can print out massive unlimited OS maps! Does that Isomage guy live around here?

[jmccann]

I wonder how hard it would be to write an algorithm using Bayesian networks to generate terrain. You could seed a map with a few locations and randomly fill in the map. I think it would be fairly simple. Rivers could use a simple physical model to determine "bendiness" based on size and slope.

I think the above tables are a good start. They might need to be extended to two hexes at least (I think 2 would be enough) - I think large scale groupings will need to have influence from at least 2 spaces distant if not further.

[Porphyre]

I'm admirative of what you did here.

There is just one point I'm probably missing: if you randomly generate an hex having one of the feature combinations with "river": how do you generate the adjacent hexes , knowing that two of six will be "rivers" too (three if you're on a confleunt)?

[machpants]

That is an awesome bit of work there Ways, thanks.

[waysoftheearth]

Aug 7, 2013 1:03:53 GMT -6 Porphyre said:

I'm admirative of what you did here.

There is just one point I'm probably missing: if you randomly generate an hex having one of the feature combinations with "river": how do you generate the adjacent hexes , knowing that two of six will be "rivers" too (three if you're on a confleunt)?

Hi Porphyre, I remarked on linear features (rivers and trails) at the bottom of my original post. What I suggested there "works" (more or less) even if it's not perfectly ideal.

Rivers are a "feature" over the top of a basic terrain type. So a hex is firstly, say, a woods hex. And then secondly it might contain a feature, such as a river. So it would be a wood hex with a river.

So for a hex next door to, say, a wood hex with a river, you'd generate the hex terrain exactly as per usual. But when you come to assigning features to the new hex, a river WILL occur without even rolling for it if all the other adjoining hexes adjoining the river have already been checked without a river occurring. That way the river is guaranteed to continue (and the same applies for trails).

Of course rivers can begin (in mountains) and end (in swamps), so you need not apply this rule there.

Trails can begin/end at towns, liars, or strongholds, and end in the open.

[Porphyre]

Right, sorry, I missed the line.

[tetramorph]

I like jmccann's notion of "seeding," a few key locations and their type before beginning the random generation. That would allow for a kind of correspondence between random wilderness generation and dungeon generation.

"It is a good idea to thoughtfully place several of the most important treasures, with or without monsterous guardians, and then switch to a random determination for the balance of the level," (U&WA, p. 6), or, in our case, wilderness. (Writing out that quotation was the first time I noticed that "monstrous" was misspelled and that there is a split infinitive. I love that! Makes my house rules feel polished!)

waysofearth, what can I say? You are the King of This Kind of Stuff! Droll pointed me over to this thread because I put up the following thread:

odd74.proboards.com/thread/10581/wilderness-generation?page=1&scrollTo=155002

Following Talysman and jmccann's idea of "blobbing," from over on that thread, perhaps something like that would "fix" the problem you and Kent were discussing, above.

Perhaps one could start by rolling up several random hex coordinates and then generating their terrain with your first, purely random generator. Then seed-point could grow outward from their respective locales until terrains meet and the map is filled.

Perhaps when generating hexes one could add a roll for how many circles of concentric hexes are the same before moving on. I am no mathematician, so I may be totally blowing it on this one. Would that blow the probabilities?

Perhaps both of the above could be combined. Seeding totally randomly, followed by contiguous generation that includes "blobbing."

Thanks for all this work!

[tetramorph]

waysoftheearth, as I've continued to ponder this amazing amount of information and the desire to keep things looking as natural as possible I wonder if mountains, as ranges, might have also been reckoned with the table with things like rivers and roads, which the referee needs to adjudicate rather freely for realism.

[waysoftheearth]

That's certainly plausible tetramorph, although it might be a side-step from the distribution of terrain and features in the original OS (where mountainous is a terrain type rather than a feature within another terrain type). It might imply something a bit more sophisticated is needed to handle the possibility of other features that can also occur in mountainous terrain.

I think you nailed it when you said "which the referee needs to adjudicate"; that's how I'd do it.

There'd be nothing wrong with laying down a mountain range--by referee design--somewhere on a blank hex sheet, and then randomly generating the terrain types around it with the tables. That approach would seem to be kinda analogous to the advice given for dungeon design in U&WA.

[Deleted]

If you want to create a random map, find Dave Wesley and Ross Maker's game "Source of the Nile." It has rules for random terrain generation including rivers that make sense, lakes, waterfalls, and taking the surrounding terrain into account.

[makofan]

The "Wilderness Architect" article in Fight On! #2 attempts to do the same thing as Source of the Nile (aka "See Africa and Die")

[chicagowiz]

Dec 19, 2014 9:09:02 GMT -6 makofan said:

The "Wilderness Architect" article in Fight On! #2 attempts to do the same thing as Source of the Nile (aka "See Africa and Die")

How would you compare the FO#2 article vs. Source of the Nile? Similar in quality/output?

I'm thinking that if the hex map of Outdoor Survival is static, it would be easy to create a generator that does the calculations and produces a key.

[makofan]

I haven't personally done a test run of FO#2, and have not played "Source" in about ten years, but I thought they looked quite comparable

Victor Raymond wrote the article.I don't know if he is active on any boards

[talysman]

Dec 19, 2014 9:51:24 GMT -6 chicagowiz said:

Dec 19, 2014 9:09:02 GMT -6 makofan said:

The "Wilderness Architect" article in Fight On! #2 attempts to do the same thing as Source of the Nile (aka "See Africa and Die")

How would you compare the FO#2 article vs. Source of the Nile? Similar in quality/output?

I haven't played or read Source of the Nile, but I did read someone's blog series of Source of the Nile solo play, since I've always been curious about the game. So I know that one prominent feature of the game is river generation (duh!)

When I waas doing reviews of the wilderness map generators I had access to, I tested the Wilderness Architect system. One of the things I nooted was that it didn't do rivers. It also doesn't do subhex details in general. (In contrast, the Judges Guild system is meant to be used with theiir wilderness maps, so it really doesn't do anything but* subhex detail. One solution would be to combine the two.)

chicagowiz said:

I'm thinking that if the hex map of Outdoor Survival is static, it would be easy to create a generator that does the calculations and produces a key.

waysoftheearth mentioned in the other wilderness generation thread that the Delving Deeper wilderness generation tables are based on the analysis of the Outdoor Survival map. So, what you're basically talking about is someone configuring Abulafia or something like that to roll on those tables.

[Deleted]

Dec 19, 2014 9:55:35 GMT -6 makofan said:

Victor Raymond wrote the article.I don't know if he is active on any boards

Didn't he develop the system right here?

odd74.proboards.com/thread/786

Looks like he was last on in September.

odd74.proboards.com/user/110

[chicagowiz]

Dec 19, 2014 14:21:18 GMT -6 talysman said:

chicagowiz said:

I'm thinking that if the hex map of Outdoor Survival is static, it would be easy to create a generator that does the calculations and produces a key.

waysoftheearth mentioned in the other wilderness generation thread that the Delving Deeper wilderness generation tables are based on the analysis of the Outdoor Survival map. So, what you're basically talking about is someone configuring Abulafia or something like that to roll on those tables.

I have never heard of Abulafia. What I was thinking was grabbing one of the hexographer versions of the Outdoor Survival Map, numbering the hexes, whipping up an Excel spreadsheet and making a quick generator.

[makofan]

Dec 19, 2014 14:49:40 GMT -6 @droll said:

Dec 19, 2014 9:55:35 GMT -6 makofan said:

Victor Raymond wrote the article.I don't know if he is active on any boards

Didn't he develop the system right here?

odd74.proboards.com/thread/786

Looks like he was last on in September.

odd74.proboards.com/user/110

so he did!

[talysman]

Dec 19, 2014 15:08:51 GMT -6 chicagowiz said:

Dec 19, 2014 14:21:18 GMT -6 talysman said:

waysoftheearth mentioned in the other wilderness generation thread that the Delving Deeper wilderness generation tables are based on the analysis of the Outdoor Survival map. So, what you're basically talking about is someone configuring Abulafia or something like that to roll on those tables.

I have never heard of Abulafia. What I was thinking was grabbing one of the hexographer versions of the Outdoor Survival Map, numbering the hexes, whipping up an Excel spreadsheet and making a quick generator.

Abulafia is basically lots of random tables in a Media Wiki wiki, modified so that they roll the results for you.

Abulafia Random Generators (www.random-generator.com)