That is not quite true, or at least it wasn't. The way it used to work, which is how I assume it works here, is that you have a random chance of a good event or bad event occurring. Once one occurs there is a check to see which are applicable. If you have no oil rigs there will not be fires in the oil fields. The negative possibilities are (were) against oil production, food production and then earthquakes. If you did not have an oil rig or a farm then the only possibility was earthquakes. I recall pci/population/ufo things, but that might just be suggestions I have read and not reality.

Slag and qz have stated definitively that the "1 building trick" does not work.

It must partly work since having no farms or oil fields make those options not available.

maybe they can divulge how earthquakes are determined generically of course

When it was still the "old school" style boards, I posted a thread titled "1 building trick?" that posed that question. Many maths were posted. Bottom line - 1 building trick doesn't help.

earthquakes etc are totally random, for example a while ago at FFA I got eqs nearly daily when doing batch explores or just building more than 10 turns in row and before that no serious earthquakes at earth empires.

I believe there used to be two different tricks that people did.

The first was building 3 farms and 1 oil rig. This was done to reduce the chance of a random event being an earthquake.

The second was building 1 of each building to reduce the chance of losing cs in an earthquake.

Neither trick works in this game. All countries have an equal chance of getting hit by an earthquake.

hmm good to know. I always built 1 farm and 1 oil rig but now I won't waste those 2 buildings anymore :)