# Main > General Discussion >  List the Most Common "Reality" Errors!

## Chick

A discussion in another thread has led to a suggestion that we need a general list of the most common "reality" errors people make.

Rivers are well covered in the excellent tutorial "How to Get Your Rivers in the Right Place", so that's a good start.

I'd like to compile a simple list of the most common errors, so please post the things you know of that newcomers get wrong.   I'll start ....


1.  Lakes have one and only one outlet.  Not 0, not 2 or more, just one.  (Yes, there are rare exceptions, but this list is for the "norm")

2.  River systems end in the ocean.  They may go through lakes, but ultimately all water flows to the sea.

3.  Rivers never split.  If they go around an island, they rejoin immediately.  A river may have multiple channels through a final delta to the sea, but the river is still just one river.

4.  Mountains form in linear or gently curving ranges.  Ranges don't meet at sharp angles.

5.  Lonely mountains form only as shield volcanoes, otherwise mountains are part of a range.

6.  Rivers don't run through (in one side and out the other) a mountain range unless there is a clear water-level pass though the mountains.

7.  Swamps and lakes form in depressions, not on hillsides.

8. Deserts form in middle latitudes, not equatorial.

9. Rivers flow downhill always.

10. Rivers run fairly straight down in hills and mountains, but wind around and meander on flat land.

11. Rivers generally taper wider toward the downstream, but most of the width growth occurs at confluences.

12. Coastlines are jagged and irregular, not round and smooth.

13. Forests should always be shorter than the nearby mountains.

14. Towns and cities should be smaller than the mountains.


See the remainder of this thread for discussions of these items.
Please continue this list !!

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## Meshon

This is a great idea! I consider myself completely out of touch with reality, so I'll do my best to avoid posting here, and learn rather.

cheers,
Meshon

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## Azélor

2- This could be misleading and not always true : http://en.wikipedia.org/wiki/Endorheic_basin the Tarim basin is clearly not a sea

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## Ghostman

> 4.  Mountains form in linear or gently curving ranges.  Ranges don't meet at sharp angles.


Sharp angle junctures might be rare (depending on just what counts as 'sharp' anyway) but not extraordinary. You can probably spot a few examples of those on this map.

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## Chick

> 2- This could be misleading and not always true : http://en.wikipedia.org/wiki/Endorheic_basin the Tarim basin is clearly not a sea





> Sharp angle junctures might be rare (depending on just what counts as 'sharp' anyway) but not extraordinary. You can probably spot a few examples of those on this map.



As I have stated, this thread is about the NORM.  There are exceptions, but they are rare and unusual and require special circumstances.  I really don't want to include them, and no one who wants reality should be using them unless they understand the special circumstances required.

This thread is about COMMON situations and the common mistakes that newcomers make, not about exceptions.  So please keep it to that, thanks  :Smile:

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## ChickPea

This is a great idea for a thread (though I just knew there'd be a bunch of people along saying X can occur in nature blah blah....!)  :Very Happy: 

I know you've pointed out that lakes have only one outlet above, but I think it's worth emphasising that - generally speaking - lakes always HAVE an outlet. That's not something I'd realised before (not that I'd really thought about it much though.) If it hadn't been pointed out to me, I would certainly have included lakes that were just stand-alone bodies of water with no outlets.

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## Chick

I thought of another list item ...

6.  Rivers don't run through (in one side and other the other) a mountain range.

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## Bobemor

2. Water always flow downwards towards the sea

Might be a bit clearer?

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## ChickPea

Here's something that I think I saw discussed once, but I'm not sure if this happens in nature often or if it's in the 'unlikely' category.

I see maps sometimes where there is a river that has its origin near the coast on one side of a continent, then it flows all the way across the land to exit into the sea at the other side of the continent. There is no mountain range or suchlike to obstruct the nearer coast. Is it realistic that a river would wind its away across a continent like that, rather than flowing towards the nearest coastline? (May as well pick your brains while I'm here!)

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## J.Edward

ChickPea - It's unlikely but water follows gravity and landform. If the landform is just right it could do that even if unlikely.

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## ChickPea

Thanks, J.Edward!

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## Chick

> Here's something that I think I saw discussed once, but I'm not sure if this happens in nature often or if it's in the 'unlikely' category.
> 
> I see maps sometimes where there is a river that has its origin near the coast on one side of a continent, then it flows all the way across the land to exit into the sea at the other side of the continent. There is no mountain range or suchlike to obstruct the nearer coast. Is it realistic that a river would wind its away across a continent like that, rather than flowing towards the nearest coastline? (May as well pick your brains while I'm here!)


Yes, Larb posted just a few months ago about the Severn River which is about 200 miles long but the source is only about 12 miles from the sea!


That question had come up in my Calisdania thread, where I had a long river (required by the client) flowing parallel to the seacoast for hundreds of miles.  For this very reason, I had put a string of hills along between the river and the seacoast to make it reasonable that the river didn't just flow to the nearest seashore.

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## Chick

> 2. Water always flow downwards towards the sea
> 
> Might be a bit clearer?


Good suggestion, Bobemor, definitely needs to be said many times.  :Smile: 

Downhill is right, toward the sea is sometimes.

There is an excellent tutorial in Tutorials (a sticky) on How to Get Your Rivers in the Right Place.  I expect I'll reference that for most of the river-related details.

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## Chashio

Actually, I thought it would be a good idea to include the exceptions; they're so fascinating and I know many of us gravitate toward mapping places that often don't fit into the norm. It would be cool and helpful, I think, to have them together--the usual and the unusual--with examples and explanations for why, when, how, what, where, etcetera, so that people can get a fuller sense and understanding of what is possible in the real world and make decisions about their settings based on a more complete view of those possibilities (and probabilities), without having to resort to asking whether or not the basic foundation of elements in their map is plausible or spending tons of time scouring the Internet for those answers when they may not know the terminology to find what they're seeking. 

I know it is a large project (immense), but I just thought it would be fun and nice to put together a collection of illustrated guidelines (guidebook?) geared for mappers, with a map (or maps) of examples, some supporting information, and links to sources where you can learn more. 

Maybe it's not a good idea, or unnecessary, or maybe it's even been done already--or it's just too much to put on the plate right now (I know I'm swamped at the moment)... but that is kinda what I was thinking, anyway. What do you think?

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## J.Edward

Now that would be a cool community project - the Guild's Guidebook to Mapping Environments!!  :Smile: 
I like the idea of knowing what the rules are before you break them, but breaking them all the same. 
If you can find 10 examples of a 'rare' occurrence it seems less rare, and then I'm okay with using it.
But i've always been a bit on the side of breaking rules.  :Very Happy:

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## Meshon

Would it be possible to edit the first post and add list items there? Then all the goodies would be right at the start and you could just include a note along the lines of "for discussion and exceptions, please see the rest of the thread."

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## Azélor

We could include something on how lakes form. 

Meandering : someone posted a nice link in February : http://thebritishgeographer.weebly.c...processes.html
Accumulation of water in a depression, because of a river input or because of precipitation. 
Past glaciations: only affect poleward latitudes, unless the whole planet froze at some point. It creates lakes but also valleys like fjords, making the coasts more rugged.
Also, poleward temperate latitudes will have the most lakes. Areas close to the tropics tend to have less precipitation and more evaporation but close to the poles, the evaporation rate is lower. 
Outlets: Again as I mentioned earlier, not all lakes have outlets. I think they are common enough not to be considered exceptions. In fact, a lot of people think they are simply impossible. It needs to be explained, separately if needed. 


A swamp can form anywhere if enough water is accumulated in the lowlands. A mangrove is different because it's made of partially submerged vegetation in salty water. 
Deserts rarely form close to the equator since it's the wettest and most humid place on the planet. But it can happen in extraordinary circumstances. 
Temperate latitudes must be very dry in order to turn into desert. They either need to be very far inland (Kazakhstan) or blocked by mountains (Nevada?) and even then, it's just a steppe. 

Just some ideas...

And of course, one thing that newcomers always forgot (but I'm not sure if it's always relevant) is that they do not know what map projection they are using.

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## Chick

> Actually, I thought it would be a good idea to include the exceptions; they're so fascinating and I know many of us gravitate toward mapping places that often don't fit into the norm. It would be cool and helpful, I think, to have them together--the usual and the unusual--with examples and explanations for why, when, how, what, where, etcetera, so that people can get a fuller sense and understanding of what is possible in the real world and make decisions about their settings based on a more complete view of those possibilities (and probabilities), without having to resort to asking whether or not the basic foundation of elements in their map is plausible or spending tons of time scouring the Internet for those answers when they may not know the terminology to find what they're seeking. 
> 
> I know it is a large project (immense), but I just thought it would be fun and nice to put together a collection of illustrated guidelines (guidebook?) geared for mappers, with a map (or maps) of examples, some supporting information, and links to sources where you can learn more. 
> 
> Maybe it's not a good idea, or unnecessary, or maybe it's even been done already--or it's just too much to put on the plate right now (I know I'm swamped at the moment)... but that is kinda what I was thinking, anyway. What do you think?


It's all fantastic ideas!  Do we want a very basic guide for newcomers trying to do their first map?  Or do we want an intermediate thing with descriptions of the exceptions?  Or do we want a fully illustrated tome gathering together all the information in many of the existing tutorials?

I think the latter is a fabulous idea, but too complex and time-consuming for most of us.

I started out to do the first -- very basic do's and don't's guide for newcomers.   I wouldn't mind including a tiny bit about exceptions, but mostly to point out how specific the circumstances need to be for them.

This thread can accumulate all the ideas you want, but for my part, I'll put together the very basic guide (maybe with mention of the exceptions, since everyone always wants to jump on them).

Volunteers for advanced versions are very welcome!!

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## Chick

> We could include something on how lakes form. 
> 
> Meandering : someone posted a nice link in February : http://thebritishgeographer.weebly.c...processes.html
> Accumulation of water in a depression, because of a river input or because of precipitation. 
> Past glaciations: only affect poleward latitudes, unless the whole planet froze at some point. It creates lakes but also valleys like fjords, making the coasts more rugged.
> Also, poleward temperate latitudes will have the most lakes. Areas close to the tropics tend to have less precipitation and more evaporation but close to the poles, the evaporation rate is lower. 
> Outlets: Again as I mentioned earlier, not all lakes have outlets. I think they are common enough not to be considered exceptions. In fact, a lot of people think they are simply impossible. It needs to be explained, separately if needed. 
> 
> 
> ...


Excellent ideas.  I'll summarize them into short line items in the list, but eventually we'll want a little content to go with each item.

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## Chick

> Would it be possible to edit the first post and add list items there? Then all the goodies would be right at the start and you could just include a note along the lines of "for discussion and exceptions, please see the rest of the thread."


Good plan!  I'll do just that  :Smile:

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## ascanius

Got one more for the list.  Uniformely jagged coasts or uniformely smooth coasts.

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## Meshon

> Got one more for the list.  Uniformely jagged coasts or uniformely smooth coasts.


I imagine this would vary somewhat with scale, but it's a good point. I just had a look at some maps and for example, Victoria Island has some nice jagged coastline and then a graceful smooth curve to the southeast. Labrador is pretty much jaggy all the way, but the northwest coast of Hudson's Bay has a great example of jagged to smooth.

cheers,
Meshon

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## Azélor

> 8. Deserts form in middle latitudes, not equatorial.


more precisely: Tropics: yes, equator: no, mid latitudes (45) usually no, poles: technically yes but generally not considered as a desert by most people


and also another idea: when making a realistic map, consider putting less rivers in dry areas, or none at all in some cases. It rain less but then can still have water flowing from rainy plateaus like it's the case with the Nile. 
and, if it's realistic, a settled region will have less than 10% of forested area if it's on a plain. At some point it keeps declining as population increases but there will always be some patch of lands that cannot be settled. This topic might also contain interesting stuff : http://www.cartographersguild.com/sh...t=20743&page=6
So, if you put forests somewhere like in eastern China, you do it for artistic purposes but it's inaccurate.
On the opposite, temperate hilly regions and mountains will have a large forest cover but most people do not mix these 2 elements. 

oh and another fine topic on a similar subject: http://www.cartographersguild.com/sh...ad.php?t=26743

Some that might be interesting:

desert in the south, tundra in the north (Game of thrones) but this is only true in the north hemisphere above the tropics
vocaloes are evil! seriously, where do I put my volcanoes?
also from Madcowchef: naming place according to their appearance as seen from above even in medieval times. Italy = boot, France= hexagon, was that a flying dinosaur ? http://www.cartographersguild.com/at...1&d=1378874254

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## jshoer

> 5.  Lonely mountains form only as shield volcanoes, otherwise mountains are part of a range.


Or stratovolcanoes!

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## Chick

> Or stratovolcanoes!


Well, stratovolcanoes form at subduction boundaries, so they normally form a chain or arc, but I guess in terms of "ranges", they are separated more than continental collision range mountains are  :Smile:  

It's a good point that we should distinguish.  Shield volcanoes tend to be isolated, one volcano over the hotspot.  Stratovolcanoes tend to be in arcs or chains.  Other mountains are in tight-knit ranges.

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## Chick

13. Forests should always be shorter than the nearby mountains.   Preferably by a lot  :Smile:

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## Mark Oliva

> 13. Forests should always be shorter than the nearby mountains.   Preferably by a lot


However, there are quite a number of places in the real world that defy this _"rule."_

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## Mark Oliva

> 2.  River systems end in the ocean.


Except for a number of them in the real world that don't.  _Always_ is a dangerous word.




> 4.  Mountains form in linear or gently curving ranges.  Ranges don't meet at sharp angles.


I don't disagree, but Prof. Tolkien didn't take you very seriously when he created the mountains of Morder.  As Che Guevera almost said, _Let there be one, two, three, many such creators!_




> 6.  Rivers don't run through (in one side and out the other) a mountain range.


Except when they do!




> 7.  Swamps and lakes form in depressions, not on hills.


Ever been to Lake Tahoe?  Well, OK, that's on a mountain, not on a hill, and it flows into Lake Pyramid in Nevada and vanishes there, so according to an earlier _"rule,"_ Lake Tahoe probably doesn't exist at all.  I could mention many other exceptions such as the Great Salt Lake, but only a churl would do that, so I won't.




> 8. Deserts form in middle latitudes, not equatorial.


However, if you look at the real world, things might turn out a bit differently!




> 9. Rivers flow downhill always.


But only if you ignore those that are affected by ocean tides.




> 13. Forests should always be shorter than the nearby mountains.


Except in the real world, where they sometimes aren't.

Onward and upward!  (Except if you're a river!)

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## Mark Oliva

> poles: technically yes but generally not considered as a desert by most people


Probably because they're usually defined as tundra instead.

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## Mark Oliva

As already noted, I'm in disagreement with a number of things in the original list.  I think they unnecessarily restrict the design of a fantasy world as well as falsely portray what actually happens in the _real_ world.  In addition, I'm not a big fan of _rules_.  I prefer _guidelines_.

Unfortunately, I had too little time available to do this yesterday, but the following is my suggested alternate list for folks who are designing and making maps for fantasy settings for RPGs or novels:

1.  Almost all lakes have one outlet.   There are some exceptions, but they are unusual.  If you make exceptions, it's a good idea to have a reason for doing so, one your readers or players will understand.

2.  Most rivers flow into an ocean.  They may flow through lakes, they may be tributaries that flow into larger rivers, etc., but eventually, they usually flow into an ocean.  There are a number of exceptions.  These usually flow into inland lakes where the water evaporates and percolates into the ground water table, or they flow on into underground rivers, which again often reach the sea.  It's a good idea to avoid such rivers in fantasy novels and settings unless they serve a real purpose.

3. Rivers seldom split.  If they go around an island, they rejoin at some point.  A river may have multiple channels through a final delta to the sea, but the river still is just one river.  Those real world rivers that do split are the result of geological actions such as earthquakes.  Many geologists believe that only one part of the split will survive in the long run.  In a fantasy setting, such splits are confusing unless they serve a clear and understandable purpose.

4. Most mountains form in linear or gently curving ranges.  Real world ranges don't meet at sharp angles.  If they do in your setting, you need an explanation, such as the might of Sauron in creating the mountains of Mordor in _Lord of the Rings_.

5.  Large, lonely mountains usually form only as shield volcanoes.  Most mountains are part of a range.

6.  Rivers do not naturally run through a mountain range.  When they do so, it usually is the result of some event other than the river that has split the mountains.

7. Swamps and lakes form in depressions, not on hills, although lakes may form in craters and depressions atop hills and mountains

8.  Rivers almost always flow downhill.  But there are some exceptions near coastlines where rivers temporarily flow upstream at high tide.

9.  Rivers usually follow relatively straight paths down hills and mountains, but they often tend to wind and meander on flat land.

10.  Rivers often taper wider downstream, at confluences and in areas where their descent becomes gradual.  They tend to be narrower where their descent is greater and their flow faster.

11. Coastlines usually are jagged and irregular.

12.  Most forests are shorter than nearby mountains adjacent to them.

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## Chick

"6.  Rivers do not naturally run through a mountain range.  When they do so, it usually is the result of some event other than the river that has split the mountains."

Actually, you missed the most common exception:  The river was there before the mountains rose  :Smile:

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## Gamerprinter

> "6.  Rivers do not naturally run through a mountain range.  When they do so, it usually is the result of some event other than the river that has split the mountains."
> 
> Actually, you missed the most common exception:  The river was there before the mountains rose


The New River in the Eastern US is actually one of the oldest rivers in the world and it bisects the Appalachian Mountains with the New River Gorge. The New River existed when the world was one supercontinent of Pangaea, and thought to be 325 to 260 million years old, and preceded the uplift of the Appalachians.

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## Azélor

> The New River in the Eastern US is actually one of the oldest rivers in the world and it bisects the Appalachian Mountains with the New River Gorge. The New River existed when the world was one supercontinent of Pangaea, and thought to be 325 to 260 million years old, and preceded the uplift of the Appalachians.


That is uncommon to the point I find it weird. I would have expected the river to change course but I guess the erosion process was faster than the rise of the mountains ? 





> Probably because they're usually defined as tundra instead.


Yes and no. Most of the north pole is covered with water. Except for Greenland and apparently Severnaya Zemlya and Franz/Joseph islands, it's all tundra only because it's surrounded by water. The presence of water is warming the area just enough. Even this place is too hot and it still considered as a tundra http://en.wikipedia.org/wiki/Alert,_Nunavut

Antarctica has a more extreme climate because it's right on the pole. Thus what I said in the original message: pole are likely to be ice desert. But there are exceptions.

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## Hai-Etlik

> That is uncommon to the point I find it weird. I would have expected the river to change course but I guess the erosion process was faster than the rise of the mountains ?


Yes, this is called a "water gap" and it's fairly common.  River erosion is generally MUCH faster than uplift. The west coast of North America has many parallel chains of mountains that are riddled with water gaps.  The Columbia, Fraser, and Peace rivers all do this at least once each.

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## Chick

Yes, there's no doubt this is a common enough situation to merit specific mention, something like "....unless there is a clear water-level pass through the mountain range."

The Delaware Water Gap of the Delaware River on the border of Pennsylvania and New Jersey is a another nice example:
http://www.flyinphilsphotos.com/psw/photos/rsz_53.jpg

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## Mark Oliva

> Actually, you missed the most common exception:  The river was there before the mountains rose


Quite right.  That's a good point to add.

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## Bobemor

Wait can someone explain 13. to me? The one about forests?

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## Sarithus

I was thinking about creating a thread on deserts as my latest map might have one and my weakness is very much on the geographical side of things. I remembered this thread though and noticed number 8. 'Deserts form in middle latitudes, not equatorial' Perhaps that could answer some of the questions I had. Could someone elaborate on that one, please?

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## Freodin

> Wait can someone explain 13. to me? The one about forests?


I second that... what the heck is a short forest anyway?

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## ChickPea

LOL, I assumed the forest thing was more about scale and proportion than geography. People sometimes draw trees on their maps that tower over mountains. You don't see that much round these parts!  :Wink:

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## Chick

> I was thinking about creating a thread on deserts as my latest map might have one and my weakness is very much on the geographical side of things. I remembered this thread though and noticed number 8. 'Deserts form in middle latitudes, not equatorial' Perhaps that could answer some of the questions I had. Could someone elaborate on that one, please?


Due to the way the atmosphere circulates vertically, regions of the Earth around 30 degrees N and S latitudes are very dry, and regions around the equator are very wet.

http://2012books.lardbucket.org/books/regional-geography-of-the-world-globalization-people-and-places/section_04/2767c17964cb3ae62ec0e4ad304d2ef4.jpg

If you want to research why, look up "Hadley Circulation".

There are other effects due to nearby ocean currents

http://myweb.cwpost.liu.edu/vdivener/notes/gen_climate_zones.gif

but you will do just fine if you put your deserts around 30 degrees and your rainforests around 0-20 degrees.

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## Chick

> LOL, I assumed the forest thing was more about scale and proportion than geography. People sometimes draw trees on their maps that tower over mountains. You don't see that much round these parts!


Yes, that is exactly the reason.  It's not a geographical question, just one of drawing them.   People tend to draw mountains, then they draw forests next to them, but to make the trees visible, they draw their trees as tall as the mountains.  

You should try to scale your world vertically as well as horizontally  :Smile: 

On this map (http://www.cartographersguild.com/al...chmentid=69908) I made the effort to get the trees to the right height relative to the mountains. 

 Here is an example of wrong proportions, although it was deliberate for this particular map (http://www.cartographersguild.com/at...2&d=1424565077), and I think you can see why it looks strange to have the trees even half the height of the mountain tops and taller than the towers in the towns.   :Smile:

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## Azélor

> I was thinking about creating a thread on deserts as my latest map might have one and my weakness is very much on the geographical side of things. I remembered this thread though and noticed number 8. 'Deserts form in middle latitudes, not equatorial' Perhaps that could answer some of the questions I had. Could someone elaborate on that one, please?


Equatorial deserts are possible but that is not the norm. Normally it's supposed to be humid unless there is a large mountain range blocking the rain.

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## Bobemor

Ahhhh, it all makes sense now. That one more comes down to the style of your map I guess

Height of an oak tree: ~50m
Height of a mountain range: ~1000m

So your mountains need to be 20x bigger than your trees as a very very general point.
Though there are trees that would only be a 1/3 smaller than some of the smallest possible mountains xD

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## Larb

While a good guideline I think the tree thing can be a stylistic choice depending on the map. I've seen some people use big trees and make it work.

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## SteffenBrand

I'm with Larb here. As long it is a stylistic choice and not an accident, there is no problem. But keeping this in mind and remember it is important for a guide. I don't think there is a problem, but clarifying it would be good. And as always with every rule in cartography there are always exceptions. =)

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## Chick

I agree, and I did exactly that in the map I linked to as an example.  All of the things in this thread can be ignored if you need to for some purpose.  It's just a guide for how to make your map look realistic geographically and geologically.  If, as Mark always points out, you don't care about that, then it's up to you, this is just a way to become aware of how you are changing reality.

To me, a fantasy map is ruined if it keeps me from picturing the fantasy world as real.  I want the elves and dwarves to live in a world where water flows downhill.  It's hard enough to suspend reality to accommodate them, without having to also suspend all the physical laws of the universe as well.  I think we need to have some portion of reality to anchor fantasy.  But ... that's just my opinion and everyone is welcome to theirs.

So that is really the purpose of this thread.  Not to insist that everyone follow reality, but to help those who want to.

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## Deadshade

> 4. Mountains form in linear or gently curving ranges. Ranges don't meet at sharp angles.


To understand why this is a quite general rule, one can examine what would be necessary to get an exception.

- Mountains are created along the line of contact of 2 plates. Obviously their 2 velocity vectors being given, the ranges will be linear and sensibly parallel if there are several of them.
- The number of plates on a planet being given, there is only a very small number of points where 3 plates meet like in a T. Only in this case *AND* if the velocity vectors are in the right direction there could arise an exceptionnal T range form.
However the probability to find such a configuration is virtually 0 because (number of required velocity directions)/(number of possible velocity directions) e.g the probability to have a T range on a triple point location is very small.

So if the number of plates and their velocities were constant, there would almost never be ranges meeting at "sharp" angles.
However as the plate tectonics is driven by mantle convection, over very long time intervals (100s of millions years) the velocity vector of a plate may change its direction.
And when it changes, it may create somewhere a new mountain range which would still run roughly orthogonal to the new velocity but which would run in a "sharp" angle to an old range created 100s of millions of years earlier when the velocities were different.
Yet in a way even this case doesn't really contradict the above norm. As erosion works much faster than range creation, the very old range is worn down and eroded compared to the new, very high and rugged mountain range.

So the rule could be adjusted  : 
4. Mountains form in linear or gently curving ranges. Ranges don't meet at sharp angles unless they were created at very different times - a high and rugged new one and a low , eroded old one.





> 8. Deserts form in middle latitudes, not equatorial.


This one is even stronger than the 4.

It is proven that the Hadley circulation happens on every planet with an atmosphere and a rotation axis rougly orthogonal to the orbit plane. The intensity and the width  of the Hadley cell can be variable but there is always one.
As this means that air rises on equator, looses humidity and goes down (around) 30° N and S we have 2 cases :
- the humidity at ground at equator is low. Then the humidity at 30° is super low and there is a desert.
- the humidity at ground at equator is high. Then the humidity at 30°  is low and there is a desert. 
This 30° desert will be preferentially located on the E of W side of continents depending on the planet's rotation direction.

The question whether there can't be a desert at equator is more complex.
Actually it depends on the ocean distribution.
As long as there are enough oceans in the equatorial zone, the Hadley circulation and the trade winds pretty much guarantee that there won't be deserts at equator.
However one could imagine a planet where the whole equatorial band is occupied by a continent, the oceans being mostly in polar latitudes. In this case most of the planet would be pretty much desertic.

So the rule could be adjusted :
8. Deserts always form in tropic latitudes (+/- 30°).  There won't be deserts on equator if there are enough oceans on equator.

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## Azélor

> This one is even stronger than the 4.
> 
> This 30° desert will be preferentially located on the E of W side of continents depending on the planet's rotation direction.
> 
> The question whether there can't be a desert at equator is more complex.
> Actually it depends on the ocean distribution.
> As long as there are enough oceans in the equatorial zone, the Hadley circulation and the trade winds pretty much guarantee that there won't be deserts at equator.
> However one could imagine a planet where the whole equatorial band is occupied by a continent, the oceans being mostly in polar latitudes. In this case most of the planet would be pretty much desertic.
> 
> ...


That's true, deserts are more common on the western side of the continents with a normal planet rotation. I'm not sure but I think it's because the winds blow toward the west at that latitude.

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## Chick

Ocean currents near the land can have major effects, too.

http://myweb.cwpost.liu.edu/vdivener...mate_zones.gif

and keep in mind that the winds and coriolis effects are major drivers of ocean currents.

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## Azélor

Hot currents can transport more moisture

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## Hai-Etlik

It's worth noting that the rotation is what defines the cardinal directions.  East is the direction facing with the planet's rotation, and north is the direction you get by making a quarter turn to the left from east. There are other equivalent ways of defining them such as north being the direction around which  the planet spins counterclockwise (picture yourself at the centre looking at the north pole). The alternative is to pick some wider north such as north for the star, north for one of the planets, the normal to the plane of one of the planets, the average of the normal to the planes of the planets, the normal to the plane of the galaxy (if the galaxy is spiral or lenticular) etc. and then pick the direction along the rotational axis closest to that, but this doesn't really have any benefit and is much more complicated.  

Also "north" and "south" have two different meanings that I've used interchangeably because explaining the difference in the middle of the previous paragraph would have been unwieldy.  The direction the pole is pointing, and the direction you need to travel from a particular point to reach the pole.  The former is is the same for the whole planet, while the latter is a field of different directions in 3D space covering the surface.  East and west only have meaning along the surface.

This is a semantic issue.  It's a matter of what the words "north", "south", "east", and "west" mean.  What's there in reality is just a lump of matter spinning along some arbitrary axis.

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## Sarithus

Hopefully this isn't too stupid of a question to ask, but on the subject of point 8, would Tibet and Mongolia and other countries around that area be greener if the Himalayas weren't there? Can I get more information on what I think is something to do with 'rain shadow' please? It just seems to me like those deserts (or not exactly deserts) extend too far up. kazakhstan interests me because it's not really behind the Himalayas but it's not as green as the line that extends from Ukraine.

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## Qoff

Which of those rules this map broke so far?

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## Chick

> Hopefully this isn't too stupid of a question to ask, but on the subject of point 8, would Tibet and Mongolia and other countries around that area be greener if the Himalayas weren't there? Can I get more information on what I think is something to do with 'rain shadow' please? It just seems to me like those deserts (or not exactly deserts) extend too far up. kazakhstan interests me because it's not really behind the Himalayas but it's not as green as the line that extends from Ukraine.


Deserts can form wherever there is not enough moisture to grow things.  The dry latitudes are dry due to atmospheric circulation.   The "rain shadow" of a mountain range is a good example of dryness due to something else.

(Simple explanation)
When a mountain range is approximately perpendicular to the prevailing wind direction, the wind is forced up and over the mountains and down the lee side.  When the air is forced upward on the windward side of the mountains, it cools as it rises and since cool air can hold less moisture, it rains a lot of the moisture out of the air.   Then when that cool air with less moisture descends the lee side of the mountains, it warms back up, but since warm air can hold a lot more moisture, the relative humidity of that air is very low.  Hence, little rain, rain shadow of the mountains, and desert.

(More technical explanation)
The rising air cools at the dry adiabatic lapse rate until it reaches the dew point and begins to condense and rain the moisture.  Thereafter it cools at the wet adiabatic lapse rate until it reaches the mountain peak line and begins to descend.  The descending air warms at the dry adiabatic lapse rate all the way down.  Since the dry adiabatic lapse rate is higher than the wet, the air ends up not only dryer, but also hotter than when it started over the mountains.

For more information, search "Foehn wind".

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## Larb

If you look up a rainfall map of Washington State in the US you can see a really good example of rain shadow due to the Cascades.

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## Deadshade

> That's true, deserts are more common on the western side of the continents with a normal planet rotation. I'm not sure but I think it's because the winds blow toward the west at that latitude.


Yes this is due to the Coriolis force. This force is due to the rotation and its direction is given by the vectorial product of the rotation vector (parallel to the rotation axis) and the velocity of the air parcel.
This force is responsible for the rotation of dépressions, anticyclones and hurricanes and for the location of deserts among others.

So for instance when the Hadley circulation gets the dry air to drop to the tropics, it starts its return to the equator (e.g southward in N hemisphere) on ground level.
But the Coriolis force deviates it towards west so that the western side of a continent gets the dry air coming from the desert whil the eastern side gets a less dry air that's coming from the ocean.
This is very schematic, is valid only for the Hadley cells and can be perturbed by mountains and oceanic currents.
If you inverted the rotation of the planet, the Coriolis force would act in the opposite direction.

What happens above the Hadley cell (e.g temperate latitudes) is more complex but the Coriolis force acts there too.

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## Sarithus

Apologies if I'm turning this into a thread to ask random questions but it saves me creating a new one just for this.

I'm sure it can be explained, but I was looking around google maps and I came across a river that just seems to split. Thoughts on this?

https://www.google.co.uk/maps/@7.802.../data=!3m1!1e3

Edit: there's all sorts of weird stuff that goes against what I've been taught looking along the white nile.

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## Azélor

> Apologies if I'm turning this into a thread to ask random questions but it saves me creating a new one just for this.
> 
> I'm sure it can be explained, but I was looking around google maps and I came across a river that just seems to split. Thoughts on this?
> 
> https://www.google.co.uk/maps/@7.802.../data=!3m1!1e3
> 
> Edit: there's all sorts of weird stuff that goes against what I've been taught looking along the white nile.


It's not splitting. It's flowing toward the north

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## Chick

> Apologies if I'm turning this into a thread to ask random questions but it saves me creating a new one just for this.
> 
> I'm sure it can be explained, but I was looking around google maps and I came across a river that just seems to split. Thoughts on this?
> 
> https://www.google.co.uk/maps/@7.802.../data=!3m1!1e3
> 
> Edit: there's all sorts of weird stuff that goes against what I've been taught looking along the white nile.


I believe what you are looking at is an old meander bed that the river has abandoned.  There is a small stream left there which is draining northward into the river from the large triangular patch, and southward into the river from the other side of that triangular patch.  In any case, the river has not split in any way, at most this is a anastomosing channel.  The river itself continues on its way despite this little side connection.

Here is an example of an anastomosing river:  http://media3.s-nbcnews.com/j/MSNBC/...a.grid-6x2.jpg

This is not splitting, it is merely making a variety of channels which eventually rejoin.  Similarly around a single island, the river does not split, only the channels do, and then they rejoin.

Even in a delta, the river is not splitting, it's anastomosing but reaches the sea before the channels rejoin.

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## Meshon

I was looking around that map link and found Lake Nasser and its crazy fractal shoreline. Amazing what a sudden rise in water with little to no subsequent erosion looks like. Also, I peered really hard but I couldn't see any ruins under the water.

Meshon

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## Mark Oliva

> All of the things in this thread can be ignored if you need to for some purpose.  It's just a guide for how to make your map look realistic geographically and geologically.  If, as Mark always points out, you don't care about that, then it's up to you, this is just a way to become aware of how you are changing reality.


Actually, I haven't pointed that out, nor is that really my opinion.

The things that are being discussed in this thread really are _very, very important_ to all of us who are trying to do serious and believable cartographic work, but the things being brought up here are not the sum and essence of all things for most users of this forum, although they are, as said, _very, very important._  However, they are not _so important_ that they tip the scales in such a manner as to destroy our work.  That can happen when advice is given, as it has been in a forum thread here, that if one abandons reality on one point, one might as well do what one wants and abandon it entirely.

Some people here map the real world, meaning Earth, the world in which we live.  A few people map fictional alternate worlds in which the _other_ world obeys the same rules as those applied to Earth.  More map science fiction _(note the word fiction)_ worlds (including versions of Earth as it might exist in the future) that often have been changed through _future_ science.  One may hypothesize and argue about what future science will produce and when it will do it, but history pretty well has shown that such hypotheses often are quite different from the end result.  In creating such a virtual, future, in some degree by science shaped world, the cartographer needs to create an alternate planet in which those things that we believe to be realities in the 21st century no longer are quite so important a guideline.  Instead, science fiction world creators and cartographers need to strive above all for believability.

Most cartographers in this guild submit maps of fantasy realms for fantasy role-playing games or fantasy novels.  Most of these worlds are filled with creatures and historical events that are not believed to have existed ever upon our own Earth and most of these worlds have been shaped to one extent or another by magic.  All of this by popular contemporary definition is _unreal_, even if some of us might believe that elves, dwarves, trolls and magic really do exist but are only well hidden.

Telling the creator, author or cartographer of a fantasy world with enchanted creatures and magic that all should follow the alleged rules of reality not only is a contradiction but also is tantamount to saying that he or she should forget fantasy to begin with.  Telling the same people that if they make things that defy the _rules_ of reality they might as well forget reality is just plain bad advice.  Just as is the case with science fiction creators and cartographers, the fantasy author and mapper need to achieve something other than reality, they need to achieve believability.




> To me, a fantasy map is ruined if it keeps me from picturing the fantasy world as real.


Taken literally, that sentence says that all fantasy maps have the potential of being ruined for you because all fantasy maps, by their nature, have the potential of being, in part, unreal.  However, I think and hope that you mean something other than that.




> I want the elves and dwarves to live in a world where water flows downhill.  It's hard enough to suspend reality to accommodate them, without having to also suspend all the physical laws of the universe as well.


I hope that none of us here is foolish enough to debate about what you want.  However, if _It's hard enough_ for you _to suspend reality to accommodate ... elves and dwarves_ I might go so far as to suggest that what you want is a bit removed from what most fantasy mappers here want and do in creating their settings.




> I think we need to have some portion of reality to anchor fantasy.


That, on the other hand, is a point upon which almost all of us probably agree.




> So that is really the purpose of this thread.  Not to insist that everyone follow reality, but to help those who want to.


In a sense, I think that's correct.  I think that was the purpose of this thread when you started it.  But I also think the contents of the postings that have been made since that start really have expanded the purpose of the thread for guild members.  I think its current purpose might now be to help guild members _use_ reality as a foundation for their fantasy creations, rather than merely to help those who want to follow reality.  After all, in a guild dominated by fantasy _(i.e. non-real in some respects)_ helping only those who want to _follow reality_ might not address many guild members' needs or desires.

Let's remember that the ideas posted in this thread go beyond cartography.  A map is not the definition of a setting but rather the visual realization of a fantasy world that has been imagined by its creator.  Thus, in any sensible discussion of reality and non-reality and virtual reality in a fantasy RPG or novel setting, one must go beyond cartographic issues to the definitions of the setting in general, some elements of which can be described only in texts and not in maps.

The idea behind this thread began with another topic that dealt with the concept of a floating volcano.  The initiator of that thread received replies that ranged from ridicule to sound supportive suggestions.  The floating volcano is a good illustrating topic, because it's not that far removed from floating cities.

In the _Forgotten Realms_® campaign setting, originally published by the old TSR® Inc. and now published by Wizards of the Coast® Inc., the old, highly magical nation of Netheril had floating cities that hovered above the world's surface, cities that high-powered wizards tore from the base upon _terra firma_ and sent upward with extremely powerful spells.

It may be that one likes or dislikes the Forgotten Realms or the Netheril part of the Realms, but the _real world_ fact of the matter is that the Realms are the best-selling, most popular fantasy RPG campaign setting ever created, one of the most-mapped fantasy RPG settings and a setting with some of the most highly-praised maps in fantasy RPG history.  Regardless of one's own likes and dislikes, there is no fantasy RPG setting and no set of fantasy RPG maps that defines the mainstream of fantasy RPG creation and fantasy RPG cartography to the extent that the _Forgotten Realms_ campaign setting does.

The truth is that I don't like today's _Forgotten Realms_ setting much at all, and I positively disliked Netheril, with its floating cities.  I thought it all was hokey.  However, my dissenting thoughts are mostly irrelevant when I give advice, because they are far from the mainstream.  Rather than pushing our own philosophies on others we might be better advised to help them to achieve their own goals.

That applies too to guild members who are seeking cartographic advice for fantasy novels.  I would argue that nothing has defined and shaped modern mainstream fantasy literature as much as the novels _The Hobbit_ and _The Lord of the Rings_ by the late Prof. J.R.R. Tolkien.

If Tolkien were posting here, he would have the _reality-or-nothing school_ all over his back.  The right-angled mountains of Mordor are nothing compared to some of his other _violations_!  Think of it:  A perfectly healthy forest like Myrkwood becomes ill because of the presence of a black necromancer.  And then once fertile lands go on over a seemingly endless distance between the Misty Mountains and the Mountains of Mordor, first turned into a desolation, then swamps where undead lurk underwater waiting to grab victims and finally plains of ash before one finally reaches those criminal right-angle mountains.

Why do these things work for most people in the realms of fantasy RPGs and fantasy novels?  I would submit that the answer is that the creators and cartographers do exactly what is and should be the objective of this thread and advice given in this guild.  All successful fantasy RPG settings and fantasy novels of which I'm aware begin with a foundation.  It is the real world in which we live, along with all of its rules of reality, true and false.  But then, because these settings are fantasy, the creators add elements that go beyond _real world reality_ into a _virtual reality_ of their own that is _unreal_ in our earthly world.  The driving force for that non-real virtual reality usually is _magic_.

This is where those who post here with fantasy RPG maps and fantasy novels can use help.  Magic changes things and makes them unreal, but for the RPG setting or novel to be successful, these changes that veer from reality must be believable or credible.  That usually is done well when the _unreal_ is integrated into a basically _real_ environment.

Once we accept the _unreal_ element, such as the floating volcano, as being a _virtual reality_ within the fantasy environment, we need to do all that is necessary to make it and its presence believable and credible.  That responsibility rests, of course, with the creator.  He or she first must give us a good explanation of why and how this magical aberration of reality was realized.  After that, however, we need to know the limits of the magic and then define how our foundation - the _realities_ of our own Earth - are affected by and will react to the magical aberration.

Successful unrealities in fantasy works seldom have empirical effects. The magical force that has created a floating volcano usually does only that much.  The spellcaster usually does not also employ additional magic to place sunshine beneath the floating volcano where there otherwise would be shade, nor does he or she usually send in magical rain to water the soil under the floating volcano's umbrella below.  If the volcano is active, there probably also is lava runoff hitting the land below.

These things usually are beyond the limits of the magic at hand.  Our foundation then needs to deal with these effects of the magic.  That foundation, being _reality_, must determine in a real world manner how the land below reacts to the volcano's shadow, its rain umbrella and the lava overflow.  Those are the ingredients that are necessary to make the _incredible_ both _credible_ and _believable_.

Fortunately, after the initial ridiculing in the floating volcano thread, this is exactly what guild members did, and they did it well.  If we want to help each other build better settings and make better maps, we need to do it on this level.  We need to take the creator's work and apply reality to it to make it believable and credible.  That helps.  Telling intelligent guild members that there are no such things as floating volcanoes helps no one.

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## Chick

I've added one more item to the list:   Towns should be smaller than the mountains  :Smile:

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## Konraw

> Here's something that I think I saw discussed once, but I'm not sure if this happens in nature often or if it's in the 'unlikely' category.
> 
> I see maps sometimes where there is a river that has its origin near the coast on one side of a continent, then it flows all the way across the land to exit into the sea at the other side of the continent. There is no mountain range or suchlike to obstruct the nearer coast. Is it realistic that a river would wind its away across a continent like that, rather than flowing towards the nearest coastline? (May as well pick your brains while I'm here!)


It may not be a mountain obstructing, just higher land than the way it has actually gone. If the land between it and the sea was ten feet lower, that might be enough for it to have gone the short route.

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## Chick

> It may not be a mountain obstructing, just higher land than the way it has actually gone. If the land between it and the sea was ten feet lower, that might be enough for it to have gone the short route.


Check out the Severn River in the UK.  It flows 220 miles but its source is 12 miles from the sea.

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## Ptakub

I see that some creating-philosophy thread emerged here, I'll say a few things I think about it.
Receiver of your art will (consciously or not) compare what he sees to what he knows. Only assuring him really strongly that something is made on purpose and reasonably, will make him stop thinking there's something wrong. That's why SW fans can be fascinated with Force and lightsabers and at the same time complain that there shouldn't be sound in space. Force and lightsabers are major elements of concept, cosmic sounds are errors made out of negligence. When in high-fantasy movie there are really bad actors, badly written dialogues and absurd script, every receiver will be disgusted because he'll see that people don't act like that in real life and there's no reason for that, it's not result of the concept but of negligence. When you have world full of magic and you show your readers some flying cities made to reinforce that impression, they'll trust you - especially if this kind of magic is result of some thinking shown in your work, coherent with overall magic description you created. But when you're drawing a map where jungle is right next to huge glacier without explanation and then, asked, you say that it's because of magic, you're treating you reader like an idiot and that's not cool, and he'll realize that quickly. Like writing the plot shouldn't be just a bunch of things that happen and composing shouldn't be just playing some melodies one after one, the same with building you whole world - it should be coherent, one thing should flow from another, there should be some reason - in world, in concept, in overall perception, anywhere, but there should be a reason that will work for your reader. And if some element isn't important enough for you to put some work in it - make it more fit to the whole, make it realistic, give it some attention from your side - then it just shouldn't be there.
And also, deciding to create something realistic is a challenge that will make your skill rise, will train your mind in creating. You have to put some work in it, not just write down bunch of ideas or draw random shapes. You will grow beyond that depending on randomness of ideas that just come to your mind - you slowly take control. When you know the reasons of things and create them consciously, then it's up to your desicion, if you want to make everything realistic, or not - and you can predict the effects.

And here's a handful of my observations, I think they're quite useful, but these aren't really rules - the first of them simplifies the reality so much it doesn't really have good examples in real world except Americas - Eurasia is too complex, Africa too random.




> I don't think it's a tutorial, so I'll place it here. I hope I won't make any bigger mistakes in grammar and vocabulary, but if I do, please correct me.
> 
> These rules aren't really universal, they have their exceptions in reality and are applicable only in really big scale - the smaller the land, the less rules there really are. That's because there are some phenomenons that occur rather in short range, so you have bigger arsenal of possible reasons of anything there. I you're mapping continent of the size of Europe - you don't really have to look here, 'cause just a little look at the real Europe will convince you that it's just too complex. Not even talking about possible worlds where normal tectonics just don't apply or you want some magic or gods to be in play. I assume we're talking about a globe which motion is similar to the Earth's one.
> 
> And of course these are just my thoughts, rules I personally use - and I'm not a geologist. So I look forward to some discussion. And, of course, I hope it will help some of you, people.
> 
> *1. Start continents as triangles.*
> Basic landmass fits into a shape of a (largely distorted) triangle. One of its edges will be the front of the plate, where it folds, creating a large and high mountain range. Behind those mountains the terrain gradually descends into plateaus, then lowlands, lakes and seas. But at the very end, on the back of the continent will be second major mountain range, but notably smaller and lower - being the relic of the past movement and collisions in the other direction.
> 
> ...

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## Applejack

I think I'm gonna have to disagree with the jagged coastlines.
While round shapes are very rare, smooth, or at least, not really jagged coastlines are quite normal.
Irregular, oke, that's undeniable.

Many maps I see have those weird peninsulas reaching everywhere, and they're often over-jagged.
When compared to a real world map, you can quite easily see the difference.
Only when you zoom in, do fractured shores become more visible, but many maps
have 90% of coasts jagged, and they're big jags, like a Norwegian fjord tenfold.
The superjagged maps also tend to throw in random islands everywhere, and peninsulas
at every corner...

Besides, jagged coastlines are ''native'' to northern regions, like Victoria Island, but look
at Africa, or Iberia. I tend to vary between jagged and more smooth.

Maybe it's just me, and I'm happy to apologize, but those over-jagged maps kinda bug me.

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## LordEntrails

IMO, jagged vs smooth coastlines are also need to consider the scale at which they are drawn. i.e. Rocky coasts are jagged at a close scale (meters) but may be smooth when viewed at a continental level.

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## Applejack

Exactly, exactly. The wrong scales and over-jagging, a lot of maps I've seen have those ''errors.''

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