RPG based on Might and Magic.

Well, in general, that's how it was. Arcomage was originally connected to the Might and Magic universe, but not to Enroth. It was artificially linked by 3DO after Might and Magic IV. Of course, there was a lot of Arcomage content after the fourth game, but at least they didn't distort the universe as much as they did in the Chronicles. As for the action series, it was clearly heavily influenced by Caningham's work. That's probably why it was so successful in terms of plot.