I'm interested in learning more about the "on activation" trigger for units.
Earlier, I'd asked if it were possible for cities to only build air units, or only ground units, as some can currently only build naval units.
I'm hoping "on activation" can be a useful workaround. But I need it to be able to do this: On activation, check for unit type, then check for if it is on a certain terrain type, and if both are true, delete unit (possibly with a return of gold equivalent to the units' cost).
For example, I'd like to rework "Over the Reich" to get rid of some major headaches found in playtesting (namely, it isn't fun to have to play with a notepad next to you to keep track of everything you discover while you individually control the army, then the industry, then the airforce). It would be much better if I could have simply a "Germany" civ rather than "Luftwaffe, Germany, and German Industry." But, I don't want certain cities building certain units. So I'm thinking, if the game will automatically delete a certain type of unit that happens to be on a certain type of square, then the player can build an Fw190 in Berlin all they want, but they'll never be able to use it (because Berlin will be built on a "city" square which will trigger the deletion as soon as it is selected). The player would instead have to build the unit in an airfield city, like III/JG2.
This would of course require the player to actually read the readme, but I think it expands possibilities for scenarios quite nicely! (No more need for house rules in Second Front Redux, for example).
Would this work in principle? I wonder if the game would crash?
Edit-the more I think about it, this would solve a HOST of problems with that scenario...