I planned to create an “Extension” for the TRC module to add the Southern Expansion to the Russian Campaign. I have read Module Design pages 106 to 108 but still have questions.
Does a map in an extension add to the map in the base module, or does the extension map have to include the base map. For example, TRC has a map A. The Southern Expansion has a map B. So, does the Southern Expansion map need to be A+B, or can Southern Expansion map just be B alone that adds to A when the expansion module is played?
I added the Southern Expansion counters to the TRC module. Will they all be available for use when playing with the extension or must all counters be added again?
All resources in the main module will always be available when using an extension (it extends).
For the map, the most basic thing to do is to do one combined map that can be chosen in place of the usual one. You can just make it a extra map that can be selected to add on below the main one, but you may have some alignment issues.
You can make completely new scenarios with the extension loaded that use all, some or none of the components of the original module, mixed with components from the extension in any way you see fit. It’s just like having a new module, except that if someone tries to load a scenario that contains extension components on to the base module, they will get warning messages and most probably errors.