This is an updated version of KodakKid3's Mapping Guide by ArcticAxis. Please note that it is unofficial.
You will need the Territory Conquest Mapping Kit to use this guide.
Step 1: Map Choice
A well-built map can be rejected if the map choice is poor. Therefore, before making a map, it's a good idea to make sure you have a good idea for a map. Firstly, a map should be geographically diverse. This means that it should contain interesting features such as impassable mountain ranges, rivers, lakes, peninsulas, and so on. Maps that lack geographic diversity, such as Wyoming, are much less likely to be accepted. Also, a map should be balanced. While, to some extent, a map can maintain realism and be manually balanced by the cartographer, some maps are just very unbalanced, like China (population all centred around Eastern regions). Unbalanced maps are less likely to be accepted, and players tend to dislike them as well. Finally, a map should not be too similar to maps already in the game. For example, there are four different Europe variants (including the original Europe map). Each has a distinct gameplay, but it is extremely unlikely that another Europe, however well-built, would be accepted. Additionally, players dislike maps that have similar versions already in the game.
If you're uncertain about whether a certain map choice is or isn't a good idea, you can always ask other cartographers and players for their opinion. After all, they are the people that will be playing on your map should it be put into the game.
Step 2: Map Template
The map template is what you base your map on. To create your map template, you'll first need to obtain an image of your map. This can be done through an image search. You'll want to try to find an image that is both accurate and clear, so that your map turns out well. Once you have your map image, upload it to Roblox as a decal (through the develop page). From this point onward, you'll be working in Roblox Studio. Download it if you need to (you can download Studio by attempting to edit a place) and open up the place where you'll be developing your map. Create a block and put your map decal on it. Resize your map block to the size that your map will be, and make sure you keep the correct proportions of your image size to avoid map stretching/squeezing (so if you have an image 200x200 pixels your X and Z dimensions for the block should match that 1:1 ratio).
Note that images that contain URLs or references to companies or websites won't be allowed as decals on Roblox. You'll need to find an image of your map that doesn't have these in order to use it for map building (though you can still use it as an external reference source as you make your map).
Step 3: Map Regions
Regions are the groups of territories in a map; the territories in a single region are all the same colour. Regions are usually states/countries or subdivisions of those if it is a large state/country. In general, regions should not exceed thirty territories. To make a region, add territories on to the map with the TerritoryPart in the map kit. Do not change any of the settings of the TerritoryPart other than the colour. Once you have filled in an area of your map large enough to be a region, group the TerritoryParts together and make them all a uniform colour. Make sure to name the new model created by the region. Keep doing this until your entire map is filled out.
When you divide up a region that is too large, you can use directions to name your regions. For example, in Confederate States of America, Tennessee is divided into the regions West Tennessee, Central Tennessee, and East Tennessee. In the case that a region is very large and/or not easily divisible into direction-named regions, you can also name the smaller regions by the names of their actual subdivisions. This is done with Texas in Confederate States of America, where Texas is divided into nine separate regions including Gulf Coast Texas and Piney Woods Texas.
Territory sizing is something to watch out for. In general, territories should be greater than a stud long and less than eight studs in both the X and Z directions. Also, territories should not be excessively long in either axis compared to the other axis. If you are worried about the blocky effect that this creates on the edges of your map, this will be resolved with terrain later on.
Step 4: Major Cities
Major and Massive cities are represented, respectively, by the dark grey and golden circles in your map kit. A Major city has the production value of two normal cities, and a Massive city has the production value of four normal cities. Large or important cities should be major/massive cities. Any territory with a major/massive city on it is a spawn.* In Europe 2.0, some of the large cities are Madrid, Toledo, Lisbon, London, Paris, Amsterdam, and Luxembourg. Make sure to position the major city correctly, and to name it. The largest or most important cities should be Massive cities. Out of the list presented for Europe 2.0, Madrid, Paris, London, and Rome were massive cities; Lisbon, Toledo, Amsterdam, and Luxembourg were major cities. The easiest way to find a list of the largest cities by population is to do a search and there will likely be a Wikipedia article on it. For example, I can search "Europe largest cities" in a search engine and I can find a Wikipedia article named List of metropolitan areas in Europe.
Step 5: Normal Cities
Normal or regular cities are the small, light grey circles in your map kit. A territory with at least two cities on it is a spawn.* Placement of cities is dependent on population. Areas with high population density should have more cities than those with low population density. Sparsely populated regions might have several territories without cities, and densely populated regions might have multiple cities on each territory. You should look up a population density map to do this. For example, if you were building a map of Russia and you were placing cities in Kamchatka (a Russian Krai), you would look up something like "Kamchatka population density" in an image search.
Step 6: Terrain (Optional)
Terrain parts are pieces that are entirely decorative. Your map kit contains two terrain pieces, each of which are called TerrainPart: a Sand blue part smaller than the TerritoryPart, and a Deep blue part. Primarily, terrain is used for two reasons. The first use of terrain is to fill in areas of the map, especially any coasts you may have, that are too small to use territories for. The second use is for water. If you plan to use terrain to fill areas too small for territories, make sure to set the Y size of the TerrainPart to 1 so it matches the height of your territories and to set the colour of it to the nearby TerritoryPart's colour. Terrain can go through territories without having any affect on playing the map, so if you plan to use terrain for water you can overlap it with territories. Also, if you're going to have a lot of terrain in your map, you'll probably want to group them by region.
Step 7: Territory Connections
A Territory Connection is a part that connects two territories that would ordinarily be unconnected. It is a semi-transparent white block named TerritoryConnection in your map kit. To connect territories, put one end of the part into both of the territories. Territory Connections must be used where territories inaccessible by other territories exist. This is mainly islands and continents. Other than these necessary points, you may place Territory Connections between any two unconnected territories. You can use them to make traversing an area faster, or as an opportunity to allow players to make flank attacks.
Note that territories with less than one stud of distance between them are traversable without the use of a Territory Connection.
Step 8: *Custom Spawns (Optional)
A custom spawn acts as a territory that a player can spawn on (the location of their capital). Ordinarily, any territory with multiple cities and/or a major/massive city is automatically a viable spawning location. However, when using custom spawns, any territory designated to be a custom spawn is a viable spawn and territories not designated to be a spawn, even if they would normally qualify as one, as not spawns. To indicate that a territory is designated as a custom spawn, place a block named Spawn on that territory. The block's appearance is immaterial, as it will not appear in-game. Note that you will need at least six (and likely more) custom spawns if you choose to include them because the maximum amount of players in a normal Territory Conquest server is 6.
Step 9: Text Blocks (Optional)
You can use text blocks to mark the regions on your map. Text blocks are the squares in your map kit. To use a text block, place it on top of a region and name it the name of that region. These blocks are simply for marking purposes, and won't be present in the actual game if your map is accepted.
Step 10: Submission
At this point you are now in the finishing stages of building a map. First, you'll need to group things together. All TerritoryParts should be in a grouped region, and all regions should be in a group. You can choose whether to group TerrainParts with individual regions or to leave them separate, but they all should be in a group in some form or another. All normal cities should be in a group. Finally, the entirety of your map, consisting of your regions group, your terrain group (if it exists), your city group, your TerritoryConnections, and the text blocks should be placed into a single group. Name this new model the name of your map. Look over your map for any errors or revisions you would like to make, as this will be the final step before the submission process. After you are certain your map is ready, select it and publish it to Roblox as a free model. Name the model the same name as the map itself. Make sure the map is actually available. Everything from here on will be on the website, not Studio.
Go to your model through the Develop page and copy the URL from the address bar. Then send a Private Message to the Territory Conquest Map Lead, Ancientvonden. Use "Map Submission" as the subject, and make sure you include your map model's URL in the message. You've now successfully submitted your map for reviewing. If it's accepted, it will likely soon be in Territory Conquest. If it's rejected, you may still have a chance at getting your map into the game. Ancientvonden will likely inform you of possible solutions to issues he found with the map, and you can try to fix and resubmit your map at a later time.