Rules:
No number spamming
No god modding
Realistic tech at the time period
State all technological developments in one way or another
Time frame is 1 day equals 1 month, but way slower for battles between nations.
No plasma weaponry
Only 100 square kilometers can be captured each month except against other players
If something like your economy changes it changes here as well
An exception to the every thing is the same is your population if you are conquering or annexing other neutral or unclaimed nations, then you gain 34,020,600 citizens per country as that is the real world average
The only other exception is military budget
If someone explicitly says that something is not know, you can not know of it or even have a suspicion without probable cause
more rules could be added
maps, they have the same scale as earth
regions/basic map
political
resources
climate zones