Not that i know of, and you must be carefull with how you set this up, it could quickly be considered multiple boards on 1 license (not allowed).
Well, as multiple forums is a feature in the software it's perfectly legit. What you're talking about is separate forums on the same board utilizing separate domains or sites which is not allowed.
What I'm saying is that what I'm doing is no different than having one "General" and one "Off Topic" forum. All I'm doing is trying to set it up so that users can easily keep their roleplaying discussions more organized.