its like idling in an irc-chatroom, and whenever you nickchange, loose connection, talk, or do anything else, you get a small amount of extra time, calculated towards your gearing to the next level
while at the same time, in a room with a lot of idle rpg'ers, you can randomly be highlighted into a tournament, and whenever your char wins, you will loose a certain amount of time, of your clock gearing you towards the next level :_)
// i know this sounds a bit weirded, but if you want a full definition, look
*here*