I wonder if it a flaw in my strategy, but I *always* do poorly on highlands (immortal, huge, dense mountains, ranges), even when I choose Inca. I even lost when I miraculously got Petra with a few terrace farms producing 6 food and 2 hammers.
I suspect that this is due to other nations being too far apart or separated by mountains, and therefor not spending resources on war efforts. (I have never tried overloading on civs - that sounds like a swell idea.)
Anyone know why this is?
When playing the Inca on Immortal on such a map, you should (in theory) be able to outperform the AI, even if everyone is effectively playing isolated. Of course, it's possible your fundamentals are off somehow. (i.e. You expand too late, or not enough, or maybe you don't emphasize research or growth enough, etc. etc.) But since you specify that this only happens on Highland maps, let's assume that you do the usual stuff OK.
Given that, here are a couple possible things that might be going on:
* In order to shine, Inca absolutely must be near mountains... ideally all cities will be founded directly next to one. Since your roads don't cost anything, it's OK for Incan cities to be really spread out. Take advantage of that: when founding cities, emphasize mountains rather than the continuous, compact empire shape that most civs favor.
* Don't be afraid to buy tiles, even if you go Tradition. The tiles that you want most (hills that are next to mountains) are almost always the tiles that cities' tile chooser selects last. In addition, since your empire is probably going to be spread out, there's a good chance that you can't rely on one of your neighboring cities to help claim tiles.
*Prioritize Construction & build Terrace Farms ASAP. They really are that good. It's extremely common to have multiple hill tiles with 2+mountains near each city, and each tile like that is amazing. Of course, they become even more amazing with each additional adjacent mountain.
*Inca usually do *very* well with Tradition, since they often have large amounts of food. (Tradition's growth bonus becomes more valuable the more excess food you have.) It's possible that Liberty might be better in your situation, since there's a lot of empty land around you that Liberty would help you colonize. However... I suspect that even then you would be better off going Tradition & just blowing past the usual 4 city limit that Tradition empires often adhere to.