What do you mean by Random Map? You mean like it picks a map at random? I just select a map without looking...it has pretty much the same effect. Once I set up the AI/opponents I want, I just scroll through the provided maps without even looking and then just select a map.
You can start up skirmish, I believe it picks a random map. Then whatever you get is whatever you play. Or you can get a random number generator, assign numbers to maps and whatever you get is what you play.