The length of time, in milliseconds, it takes for the alter aeon game server to respond to a command. A high level of lag is considered an annoyance and hinders playing, anything greater than 500ms is considered notable. Lag can occur for different reasons, it is not necessarily a fault of the game. it may be a fault on the server, the client or anywhere on the route from the server to the client. To view recent server lag type graph 13 <no of lines>. To help protect players from death, the Lag monster will restore players when high levels of lag are detected by the server.
If using dclient lag can be seen in the bottom right hand corner of the window.