This is a detailed guide to map legality (a.k.a. making sure your map actually works), though it mostly focuses on how to find out if your map is the right shape and size. A quick summary of this page can be found back at Mapping Surveying Guidelines.
The Region Map is what is used as a guide to properly determine if your map is correctly sized and shaped.
To figure out if a new map is legal, there are three main criteria it needs to pass:
- Concept - Make sure the map includes all confirmed details about that map.
- Spatial - Is it the size and shape it's supposed to be? If the Region Map says it should be a horizontal route about 100 tiles long, make sure it is. Try to fit it as best you can.
- Technical requirements - Factors and design decisions that are required for all maps.
It is important to note that it's impossible to exhaustively define what each of these entails, so the descriptions below will just say as much as can be thought of. Also note that there is some amount of wiggle room in each of them (some more than others).
It is important for a map to match the location's concept, but it's also important for it to match the adjacent areas as well. Its style shouldn't deviate too radically from that of the surrounding areas. For example, Route 7 is between a large industrial city and a dusty, run-down western town, so it shouldn't be a lush field of flowers and crystal-clear streams.
The term "biome" should pop up around now. The Region Map is colored in according to confirmed biome, and the type of biome allocated to a map by this should be followed unless the mapper has a good idea which requires something different. The transition from one biome to another should be in roughly the part of the map that the Region Map says it should be in.
The Region Map also has contour lines, which show the elevation of land and how it changes. These are just a rough guideline. Obviously it would be nice if the map tried to adhere to them, but it doesn't matter if it doesn't. There is no fixed value for how many cliffs correspond to one contour line.
Beyond biome, there is very little information available for what a particular map should be like, and even less of that is confirmed. Make sure you know what is confirmed and what is just headcanon. You can ignore headcanon if you want to - there's nothing wrong with following it either, but a map won't be illegal just because it ignores headcanon.
This is about making sure the map adequately fits the space provided for it on the Region Map. It is arguably the most important criterion. This is where the Region Map File is very useful.
The Region Map is a guide for how big and what shape each map should be, and how they should connect to each other. The Region Map has a scale, with each grid square in the Region Map corresponding to a certain number of tiles (30x30). A map should be the appropriate dimensions and be the appropriate shape that the Region Map says it should be.
However, maps can have a little flexibility to them. They can be wider or narrower than the Region Map says they should be, so long as the difference is less than half a grid square (15 tiles) on each side (i.e. +/- 30 tiles in each dimension). Yes, this means that overlaying all the game maps onto the Region Map will not have them match up perfectly, and that's fine. The Region Map is only a guide, after all. The flexibility in map sizes will cause some stretching in certain parts of the region when comparing the game maps to the Region Map. Even if this stretching is significant, making some game maps look like they should occupy different grid squares in the Region Map when they're overlapped, the Region Map will not be adjusted because of it (i.e. by changing which grid squares certain routes/towns occupy).
A map cannot be larger or smaller than the above flexibility states, even if there is space for it to be made significantly larger/smaller. For example, although the east side of Dronia isn't bound by anything, it cannot expand in that direction more than the half a square allowed by the above.
Bear in mind that, because Urobos features several "loops" (circles formed by connected maps), map size flexibility can interfere with this. Since we want all our maps to connect together perfectly in the end, it may be necessary for some maps to dictate exact dimensions and other rules which those maps must follow, in order for it to complete a loop properly.
Connections to other areas
If one map is connected to another, then the exact position of that connection can be anywhere along the edge of the grid square which features the connection. For example, the southern exit from Dronia to Route 9 can be positioned anywhere between the south-west corner and the middle of the southern edge of Dronia, as Dronia is 2 squares wide.
It is recommended, however, that a map's connection to another map is placed in the centre of the connecting square's edge. This reduces the risk of two maps connecting corner-to-opposite-corner, which is definitely not desirable because such a connection would imply the connection is diagonal rather than straight on as it should be. The connection between Dacapo Town and Route 1 is this kind of connection, but it is widely considered a mistake and should not be repeated.
There is a way to change the above rules, though. A map can be submitted which features a connection at a different point on its edge to where the Region Map says it should be (e.g. the connection from Dronia to Route 9 being on the eastern side of the southern edge of Dronia). In this case, if certain changes can be made to the Region Map to accommodate the different connection(s), then the map would still be acceptable. If the map then wins, the Region Map will be changed accordingly to show the connection being where the map has it. The specific changes made to the Region Map will be voted on after the map wins, and can only affect the shape/size of routes and towns which have not yet been mapped (already mapped locations may be relocated if necessary). It will be noted during the surveys that the map will require a change to the Region Map to accommodate its layout. Note that the map will not be acceptable if there is no way to change the Region Map to accommodate its layout. In any case, the connection must still be on the same side of the map as the Region Map shows it to be.
Coherency with other areas
Where two maps are connected, their terrain should also connect properly. Cliffs should flow from one map to the other, paths should carry on, trees should appear properly tiled, and so forth. There should not be any disconnect caused by something on one map looking like it should carry on into the other map but doesn't (e.g. a river from one map abruptly stopping because it wasn't also depicted on the other map).
It should be possible to properly match up everything while making a map, unless the other map it is connected to is also being made at the same time. In that case, they will be fixed accordingly, although it is recommended that the connections to such maps be relatively standard, e.g. just a path through trees, containing few or no unusual features like cliffs or rivers or buildings.
A map is said to be in a pocket dimension if it is disconnected from all other maps AND it is a different size inside (the map itself) than it appears to be from the outside (inferred from nearby areas). Caves and forests are both examples of pocket dimension, as are the interiors of all buildings.
A pocket dimension map needs to be teleported to, and cannot be walked directly into from a connected map. This can be done by entering a cave mouth, passing through a gatehouse, or walking into a cluster of trees. Note that the presence of a gatehouse does not in itself mean that the space within is a pocket dimension.
The exact difference between the interior and exterior sizes of the map can vary between different pocket dimension maps. Often the distance between the entrance and exit of a pocket dimension map is much smaller outside than it is inside. However, the relative directions between the entrances to the pocket dimension map should be about the same inside as outside, even if they are much further apart inside. For example, Viridian Forest has southern and north-western entrances, which are shown in both the interior and exterior maps.
As pocket dimension maps do not connect to other maps, they do not need to be checked for spatial legality, other than checking whether their entrances are in appropriate places both inside and out.
There are certain requirements for how maps can be made. These requirements allow them to be usable in Pokémon Sage, and must be followed. They include:
- No black void - The player should never be able to see the black void at the edge of a map. Make sure there are enough "buffer" tiles around the accessible areas (a minimum distance of 6 vertically and 8 horizontally) to prevent the player from ever being able to get close enough to the edge of the map to see it.
- Use a short tileset - Your map must NOT use the giant-ass tileset. Just don't, okay? Nothing can properly handle its length. Make your own tileset out of the tiles we have on the Dropbox (which also has some base tilesets to get you started).
- Map connections go on the edges - If the map connects to another one, the boundary of that connection must be at the very edge of the map (because maps only connect at their edges).
- Include trainers (for routes only) - Trainer placement is just as important for map design as obstacles or tall grass. If you are mapping a route, you must include trainers. These trainers and their positions are subject to change after the map is confirmed, but they should be included at least temporarily.