First of all, I'm really enjoying the game and Amplitude is making a wonderful and transparent develop.

I had trouble understanding when i can build my first city. It seems like upgrading an outpost to a city is a forced action as soon as you unlock it. 

I felt a little disappointed, beacuse i created two outpost thinking the second one would be the city and the first a mining site, but was forced to transform the first in a city instead. As soon the city upgrade was avaiable i was unable to skip the turn without making the city. 

This eventually led to a problem in a second playthrough that forced me to reload: I was ransacked at the same time the forced city creation appear, so I was unable to skip turn (to kick the rival tribe's ass) because of the forced action, nor could i build the damn city, because I was being ransacked.

So I was wondering, how does city creation actually works and when it's avaiable? Is there a hidden outpost rule I passed by?

Thankfully,

Rauhmones