the situations depicted can be stronger than in a traditional. I would, however, caution that if a member of the nobility, particularly a main character, acts contrary to the generally accepted rules of the era, then those actions must be thoroughly justified; i.e., a reason must be given. Not even an Historical can violate the rules that much. Or rather, yes, you can do it, but knowledgeable readers and reviewers will not accept it.
Common mistakes. Among the things that offend Regency readers of both genres are: incorrect use of English titles. Titles are almost an art form. And they are not flexible. Faithful Regency readers tend to have an excellent grasp of titles, so, attention, authors! You can’t write about this era without understanding titles. Another top-of-the-line offense: having a bastard inherit a title or having a legitimate heir “disinherited.” Can’t be done. No way, no how.
Another frequent error. Use of terms that could not possibly have been known in that era (a reference to train tracks, for example; to Freudian psycho babble, or, heaven forbid, a zipper). Use of eighteenth century clothes in an era when fashions had made a dramatic change; i.e., no hoop skirts, wigs, or tricornes allowed. Swords and highwaymen were also fading into obscurity. Duels were illegal. Yes, they happened, but furtively, and not nearly so frequently as in the past.
Unacceptable manners. Other no-no’s include: having members of the nobility, or even the gentry, fall into casual conversation with someone to whom they have not been introduced, particularly in a formal setting, such as a ball or court presentation. Use of first names. A couple might be betrothed before they were on a first-name basis. Manners count, even in an Historical. Yes, characters in an Historical will be more likely to break away from their upbringing, but that core of civilization should still be there, particularly in the hero and heroine. They should triumph because of who and what they are, and also because of what their society made them.
Although Regency society was outwardly frivolous, leading to the radical swing to what we now call Victorian morality, there was a basic core of responsibility, a