It's my understanding that battles between civilizations in ancient and medieval times (i.e. the time before gunpowder weaponry became widespread) were often pitched affairs in which soldiers fought in big formations, like the battles portrayed in the Total War games. But that leaves me scratching my head as to how civilizations located in jungle regions (e.g. the Maya, Khmers, or some of the Central African kingdoms) would have fought battles like that. I imagine it would be hard to keep your soldiers together in formation, let alone maneuver them around, if there are lots of trees and bushes getting in the way. Would these cultures have done all their fighting in open clearings rather than within the forest, or did they simply not do big pitched battles at all?