Warfare had been a part of Maya culture for centuries, but its intensification and scale increased prior to the collapse so that cities began to build fortifications. Previously, warfare had often been token, in that defeat might result in only a small number of important figures being taken as captives. By the Late Classic period, war seems to have been much more damaging to all involved. The conquest of territory and the capturing of a large number of sacrificial victims now became a priority - the former perhaps to increase agricultural production and acquire resources and the latter to appease the gods and return to the more stable times of earlier centuries. The presence of large numbers of arrow heads at certain sites is further evidence that life in the cities was becoming more precarious….

...Over-population may well have put an unbearable strain on the agricultural production the Maya were capable of managing. Ever more archaeological evidence shows that Maya cities and peripheral settlements were much more heavily populated than previously imagined. Even worse, scientific evidence clearly indicates that the Maya lowlands suffered a sustained series of droughts between c. 800 and c. 1050 CE. However, it should be noted that not all cities suffered from droughts, as some lakes and rivers never dried up completely. For those regions which did suffer a water shortage, the lack of rain and repeated crop failures make it entirely conceivable that either the lower levels of society - 90% of the population were farmers - or perhaps more likely, non-ruling elites, rebelled against the ruling class, who could no longer justify their role as protectors of society and intermediaries with the gods such as Chahk the rain god.