Duncan is a shrewd advisor, always preferring to take a measured approach rather than jump to aggression. He suggests diplomacy first in most situations, despite sharing the Forresters' hatred of the Whitehills. Due to this, he does not think very highly of Royland Degore, who prefers to show strength rather than submission.

Duncan ultimately intends to defend the House rather than any one member, and therefore has the potential to betray his lord and go behind his back.