At first the answer seems simple: 8 mile per hex is the most detailed scale, therefore it is the best. Where we don't have 8, 24 should be used, and 72 should only be used where there is no more detailed scale to work with.
However, the first problem comes when we try to fit differently-scaled maps together. There is often a problem with where to place the hex grid. In fact, this problem sometimes appears within maps of the same scale (compare the Expert Set map with the detail of the same map in X8, for example). But it becomes much worse when dealing with maps of different scales.
Next, there is the not insignificant problem of inconsistency between maps. Compare any two maps of the same scale, and you will likely find that they differ slightly in their placement of elements (borders, coastlines, rivers, roads, sometimes even settlements).
Another problem arises with areas shown only partially on the edges of maps. When these partial glimpses are the only sources, they can be an important resource, but unfortunately they often don't line up with other sources.
Which brings us to the biggest problem of all: important elements such as coastlines often don't line up. I have recently discovered this to be the case with all of the large scale maps: the Dawn of the Emperors map, as well as the Poor Wizard's Almanac maps. Specifically, attempting to overlay the 8 mile per hex coastlines, which I find are generally compatible with the 24 mile per hex coastlines, onto the 72 mile per hex map reveals that the maps are in fact different. It is impossible to place the coastlines on the map and have them all line up.
This is all very confusing, and I'm not at all sure that I have managed to successfully explain the problem. But if anyone has any comments, comiserations, suggestions, etc. I would be very happy to hear them.
When it comes to combining the maps, or combining scales, I think however much you try to find work-arounds and arrive at a concensus, in the end you are going to have to do what everyone else has who has encountered this problem:
Stick your neck out and say, "This is how I think it should be". :P
Listen to those who have gone before, and then make the call based on your own best judgement.
To be honest, you are producing maps of a quality I haven't seen before, and I for one will be happy with however you resolve these issues.
As for the question of what scale to use, I think the decision should be driven by two issues: how large an area you intend to cover (as a map can only be so large before it becomes unweildy) and the level of detail you want to provide.
Gordon
Or am I remembering wrong?
RPGpundit
If you want the maximum number of people using your maps, you can stick with a few additional guidelines.
1) Harmonize as closely as possible between maps.
2) When 1) doesn't work, and you have to change or fix something, make the change to the map that has the least impact. "Least impact" is a qualitative term where your judgement comes in, but least impact should include considerations of how much each map is in use compared to other maps(change the map less likely to be used by DMs), what features are being changed(axing interesting terrain features is less desirable than plain coastline), and whether you are adding or subtracting(adding something on one map to another is usually better than subtracting).
what about the 40 mile hex? Isn't the Hollow world mapped out at 40 per hex?
Or am I remembering wrong?
You are remembering right. The main Hollow World map is indeed 40 mi per hex. The scale was left off the original maps, but later mentioned in The Princess Ark in Dragon by Bruce Heard.
Thanks for the vote of confidence, guys.
I realise that in the end I will have to simply take control and do what I think is best, but I'm trying to put that moment off as long as possible, in order to keep my maps as "official" as possible, and therefore useful to the greatest number of people.
Point the second: It is easy to start with a large-size, low-detail map and add details as you 'zoom in'. It is somewhat harder, in my experience, to start with a set of small-size, high-detail maps and effectively 'zoom out' without making a mistake along the way in patching your work together. (Especially if your small-size maps already contain an inconsistency or three in material they jointly share.)
Just a general suggestion.
Point the first: He who has the gold (or in this case, does the heavy lifting) makes the rules.
Hehe.
I agree with this, but while in the end I will of course do what I want to do, I'd rather the maximum possible number of people are able to benefit from my work too. This makes me more thorough in my investigations of problem areas, too.
Point the second: It is easy to start with a large-size, low-detail map and add details as you 'zoom in'. It is somewhat harder, in my experience, to start with a set of small-size, high-detail maps and effectively 'zoom out' without making a mistake along the way in patching your work together. (Especially if your small-size maps already contain an inconsistency or three in material they jointly share.)
It is easy as long as the maps are consistent, I would say.
Let's take the Hollow World maps. The Iciria map doesn't fit very well with the world map for the Hollow World, unfortunately. This is a bit of a problem, but the Iciria map holds the more detail - and the more useful detail at that - so in the end I'd rather revise the world map to fit it into the Iciria map than vice versa (which would be horribly difficult). Add to this the very tight consistency between the 40 mi per hex Iciria map and for example the 8 mi per hex HWR2 Nithia map, and the world map loses hands down.
Thus I find myself in the situation of being forced to resolve problems with the world map before I can use it to add areas to the Iciria map. But at least I have a nice large scale 40 mi per hex map to help things along.
Now look at the Known World. Unlike the Hollow World, things were not kept consistent between scales, and a huge number of errors and inconsistencies crept in. Believe it or not, these are mostly in the large scale maps, not the detailed 8 mi per hex maps.
For example, take the relative positioning of the Isle of Dawn and Alphatia. There are three maps that show this in the Dawn of the Emperors boxed set. The first is the 24 mi per hex Isle of Dawn map, which shows a large portion of Alphatia. Next is the 24 mi per hex Alphatia map, which neglects to show the small area of the Isle of Dawn that should appear on that map. Nevertheless, it's possible to put them together using landmarks such as settlements. These all match up nicely. However, unfortunately the coastlines do not match up. The Alphatian coastline is about half a hex out of synch on each map.
My solution is to go with the Alphatia map's coastline, because it shows the whole coastline, not just a part of it.
Now let's look at the third map, the 72 mi per hex Known World map. This map was (presumably) scaled up from the original 24 mi per hex maps, which of course are the original maps of the Known World. But whoever did the job obviously wasn't aiming for total accuracy, because again the coastlines are out of synch. In this case, extremely out of synch. Again, this will require fixing before the 72 mi per hex map can be used as a source for smaller scale maps. This is quite a big problem.
This is an example of how the scales fit together, from the map I've been working on for the past week or so. Look at the bottom of the image to see the large 40 mile hexes. The 8 mi per hex map is overlaid. You should be able to see where the 40 mile hexes fall in line with the larger scale map. In fact, this map is extremely well aligned with its source map (i.e. the 40 mi per hex map).
You can see the full Nithia map tomorrow in my mapping thread, then try superimposing it with my Iciria map and see for yourself.
This is the kind of map I hope to be developing in the near future, when I exhaust my official sources. That day is creeping ever closer, because it's not going to be too long now until I have no official stuff left to work from!