I don't like the idea of negative traits. There could be another negative mechanism added in, much like the negative traits of civics. That way, much like for leaders themselves, the negative trait would be caused more by the playing style of the player rather than an unchangable trait. For example, for extravegent trait, we could have a higher maintancence penalty if too much wonders are built. It wouldn't make much sense to have a higher maintenance penalty if the player never built a wonder. Or arrogant, because what if the player plays as a nice guy?
I could see how a counter-arguement would be that a player could never go to war and yet they still have the aggressive trait. However a player wouldn't mind having a positive trait because naturally we get more angry at traits that hold us back than happy about traits that help us. Basically I think the game would be less fun if negative traits were added in. I understand that this mod is suppossed to be more realistic, but there still needs to be a balance, although moving the scale more towards realistic than in the regular version. I would be more in favor of new negative mechanisms that reflect playing style and are changable rather than unchangable negative mechanisms.
As for adding- Anything that would cause more rise and fall. Throughout history by far the most common source of a falling empire is some kind of combination of bad leadership, falling income, and military threat. That being said, the GNP part should probably become more significant as time moves on. As in our modern age most likely the US will be surpassed by economic means, not by military conquest. I honestly have no experiance with actually moding so if anything sounds like too much, please stop me. As for the main mechanism, I would say the military thing is pretty much down pat as of now. I mean, it is unlikely that a human with a strong military will ever be conqured, but I think that the cause of the decline in military would most likely come from a decrease in income. Therefore, I think some sort of way to make income far more volatile would cause the player to have to decrease his/her military, and then another military threat can come in and conquer you, and then later you can have your revenge by using smart playing to build up you income again, and conquer you conquerer. Hence avoiding the unfun part of being brought down and not being able to get back up.
Meh, the idea I mentioned above is very vague. Unfortunatly I don't know enough about the game's mechanics to get any more specific. I guess making trade routes a larger source of income and making them volatile, or at least have a way of another civ affectiving another civ's trade routes would work, but I'm not sure.
with natural gas
as oil power plant or coal power plant.
