I create random map scripts in Age of Empires 2for Age of Empires 2. My most recent one beingmost recent one is for the HD version, which can be found here http://steamcommunity.com/sharedfiles/filedetails/?id=172861335.
If you're looking to understand how to create maps for Age of Empires 2 create their maps, there is an excellent guide to RMS (random Map scripting) which can be found here http://dgdn.net/dgdn.php?id=3&cat=article_pages&heading_ID=1&cat_ID=3this excellent guide to RMS (Random Map Scripting).
Age of empiresEmpires uses an expert system which allows, allowing scripts to write routines for the generation rules, which you can learn a lot from. As for regions, I imagine that would simply be a case of masking off areas and applying different scripts/routines to the masked areas accordingly. You can easily see the generation rules of existing map scripts by opening them in a text editor,. I write mine in Notepad.
If you'd like to ask any questions feel free to contact me at [email protected] via skype or email.
All the best,
-Andy