Resource prices vary depending on a lot of factors. It's quite complicated, but the AI will tell you what they want for them. Selling resources for gpt is good. Take as much gold as they are willing to give. Trading health/happy resources one to one is pretty normal.Btw, is there any usual prices(gpt or gold) for resources and techs or is it situational? I try to do 1 on 1 trades or equal beaker cost for techs but sometimes i don't have this opportunity.
But is it completely random (like the tiny chance for a mining resource from a normal mine) or somehow connected to overall production, population, green faces or whatever?
One for one in / resource trades is the norm for much of the game, as all of them except gold and ivory have the equal value. The actual value for a resource offered by either side is tied to the city count of the smaller trading parties civ.Resource prices vary depending on a lot of factors. It's quite complicated, but the AI will tell you what they want for them. Selling resources for gpt is good. Take as much gold as they are willing to give. Trading health/happy resources one to one is pretty normal.
Hopefully somebody with actual knowledge will pop in and answer this, because I simply don't know. But I think it depends to an extent on in the cities. For example, in a recent Rainforest map I played, I got Global Warming in ~1500AD, and that mapscript has few health resources so almost no matter what you'll get in the cities.
Kmod bases it off unhealth I think, but plain BtS bases it on nukes fired.
That can't be the only factor then, because I've yet to see a single nuke in any of my games, but global warming happens in most of them.
I don't know the formula, but nukes do (oddly) set off global warming, but it can happen (at a much lesser rate) without nuclear warfare.Nukes could have been a factor in my game because the Persian was nuking Churchill on the other continent while I was happily building my spaceship...
(I built a few nukes but did not fire a single one)
BUG mod will show the city-count for non-vassal civs on the main screen (and the number of vassal cities known to you as well). You can't get the count of vassal civs in the trade screen as vassals can't trade cities. (That's why BUG doesn't show it.)City count of an AI is easily found by counting the city names in the trade screen and adding one (the capital is hidden!)
I think destroying your own roads/rails is only possible in mods.