Desync
a desync is where two or more computers in a synchronised multiplayer game (such as duke) stop behaving in the same way.
DESYNC can be caused by problems with eduke con code (prior to eduke there was insufficiant power in con to do it) by bugs in the game source by network conditions or by insufficant computing power on one of the peers in the game.
duke detects certain types of desync and gives the message "OUT OF SYNC PLEASE RESTART GAME". However there are also things that it does not detect desync on and provided care is taken theese can be usefull to mod authors (for example a cloaking device that hides you from everyone who is not using nightvision).