I've been told by a friend who spent a few hundred hours looking at DAOC in a debugger that each instance of DAOC creates a mutex that other instances look for before they run. Assuming that he's right -- and I have no reason to doubt him, he's a very good programmer -- I can't think of any way that you could run more than two instances without violating the EULA. But maybe there's a way that isn't occurring to me.