hi Mike, I play only xiangqi but am in the process of learning changgi. I know the basics but am unsure of all the rules because I'm being taught in Korean in Korea and my Korean is a work in progress too. Let me ask about that rule...!! In xiangqi, the kings can't even oppose each other in the first place. I am good at xiangqi though, I learned it when I went to university in China and can beat the avg Chinese guy off the street. I can't say which is better, bc i'm such a novice at changgi. Interesting to note that even though Koreans COULD write changgi pieces in hangul (written Korean), they leave it in the original Chinese...that should be a lesson to us as well to keep the universality of the game. In Korea, i have yet to see any octagonal pieces!