So, my own pev peev with the game is the ease with which to build new cities.

I mean, come on, in a world of darkness and fading suns, you are suppose to have growing civilisation.

Back in 2003, when I played this game a lot, I solved this by simply increasing the price of the engineers by a factor of 25. I simply went into the unit.dat fil and changed the numbers.

In the gog-version, however, this only changes the cost for me, e.g. the AI house can still build at the original prices. Does anyone know how to edit this?

If i remember correctly, while the AI ignores resource costs when building units, it still does follow the build time, so the only way for you to limit it is to increase the build time of engineers instead of the resource costs.

Other way to limit the city sprawl that the AI does is to also limit the type of cities that can build engineers. While in vannila all city types can build engineers, you can mod it so only 1-4 city types can do so. I normally mod so only Palaces can build them, and since you can only have one palace per planet, you limit the number of engineers both you and the AI builds.

Combining both methods (increased build time/city type restriction) should allow you to reduce significantly the urban sprawl that the AI does.

Are either of you in the EFS mod Discord server?

Nope. How do i join?

https://discord.gg/xSzJfESpzP

Introduce yourself when you join

This is something I encountered to my dismay in returning to the GoG version instead of an abandonware mod. The AI city-spams like it's going out of style. One of the mods (Reality?) limited this spam by restricting Engineer production to only certain city types (as Makinus said). It's a good thing to limit, especially since the only way(?) to destroy a city is to bombard it to death while you don't own it.

How do you accomplish this in the unit.dat file? If I understand it correctly, you have the choice between a setting that says a unit may be produced at any type of city, only at one specific city type, or nowhere at all. How do you get several city types but not all?

Sorry for the late reply. To do that, you copy the unit entry and assign it to a different building. Like if you wanted them built only in palaces and factories then you'd assign one to 0 and another to 3. Under-the-hood they're technically different units but practically and functionally speaking they're the same one.