I didn't want to address this now but reviewing China's tech pace has revealed that it's important. Basically, the problem is that balancing China's tech speed is very difficult. They usually start out slow, but at some point overtake all other civilisations and then usually end up as the clear tech leader by a wide margin. Only their collapse (usually at the hands of the Mongols) puts an end to it, and their respawn is technologically far enough behind for the problem not to come up. But if they survive their tech level only accelerates to unhistorical levels and never slows down. In many ways, China with its great terrain but slow start has the most exponential tech curve in the game. I tested them with various configurations (different modifiers) and even with the UP completely disabled that was the case. They seem to reach tech parity with other civs around 200 BC and shortly after gain a significant lead. Historically, they should probably be less behind in the ancient era, be competitive in the late classical era, take the lead in the medieval period and the quickly fall behind again. In the hypothetical scenario of surviving the Mongol invasion, they still should plateau and not continue their exponential growth. As mentioned above, such a outcome is already hard enough to balance without the UP (and I don't think possible without era based modifiers which are disabled as well at the moment), but the UP exacerbates the exact problem that I need to address. Or put another way, any solution to the tech pace problem would directly counteract the UP so I cannot attempt them (for example China needs to be exempted from the tech leader penalty because it would nullify the UP). In other words, China's UP needs to be replaced with something that does not cause an exponential tech speed. This thread is here to discuss ideas for the replacement. I would like to focus on ideas that would help China technologically in the classical and medieval eras only, or encourage isolation in some way. But I am also open to ideas in general.