So I started watching a bit of civ 5 streams, and I often see them demanding tribute from city-states. It seems like a really good way to boost your economy early game, and I was basically wondering just how it works.
I usually play single player though, and the AI's tend to pledge protect to most of the city-states they meet, and I understand that this makes city-states more reluctant from giving tribute. They are also more reluctant if you have negative influence with them, and they're more likely to give tribute if you got nearby military. But are there other things that determines whether a city-state is more or less likely to give tribute? Does them being Irrational, hostile, friendly etc. mean anything? I also heard a streamer saying it was easy to get tribute from a city-state because it was flatland city-state, is that true?