Chaotic Evil characters will do anything that will have a pleasing result to them. They are interested in maximum gain for minimum risk. They often do not care to undergo the very treatment they inflict, but they have no interest or belief in the principle of "treat others as you expect to be treated." Chaotic Evil characters rarely plan very far in advance, preferring to handle situations on a day by day basis.
The combination of unpredictability and utter disregard for anyone else makes Chaotic Evil characters the most dangerous type of foe the PCs are likely to face. Chaotic Evil characters often develop sadistic and macabre personalities. They are often spiteful and see everyone as being just as reprehensible as themselves. Chaotic Evil societies are often crude and loose bully associations, where any one individual can jump to the top instantly by defeating the leader and any other challengers. As a result, the leader is rarely in place for long, and if he has been he has weakened the whole group such that no two (or even three) others can threaten him. This is done by murder of anyone who poses a challenge to rule.