Here's the deal. Fantasy-ish setting. I've got a baron who has kicked the bucket and his son is about to step up take his place. How is the son addressed? I've found some conflicting information. Some places tell me he should be called "The Honorable _____", and others "Lord ____". The Honorable ___ makes me think of a judge.
You can address him as Baron_________ (this would be for introductions or acquaintances) or Lord__________ (Those closer than acquaintances but not close enough for usage of first name).