[If you have not yet seen the film, plot details below may contain spoilers.]
Roger plays a relatively secondary role in the film. He is depicted as an indifferent father, more concerned about his son's having cut holes in the family's Egyptian bedlinens as part of a ghost costume than he is about the troubled boy himself.
At a "happening" (or ball) given by the family for the townspeople of Collinsport as part of an effort to reassert the family's role in the community, Roger is shown to be a womanizer, a liar and a thief, stealing from the guests' belongings in the coatroom while seducing the female attendant and - as part of his effort to seduce her - denying that he even knows who his son is. These actions are observed by Roger's recently arrived vampiric "cousin," Barnabas Collins , who is literally "hanging around" outside a window, prompting Barnabas to take action against what he regards as conduct dishonoring the family.
Roger's most critical action comes relatively late in the film. Confronted with a choice by Barnabas of taking a lifetime income and leaving Collinwood forever or of adopting a more genuinely involved paternal role with his son, Roger coldly abandons David and the rest of the family, speeding away with little show of regret in a taxi. Roger's departing scene sets in motion a sequence of events which expose the upset David to mortal danger, prompting Barnabas to accidentally move into an area of bright sunlight while saving the boy. As a vampire, he thus begins to smoke and burst into flame, causing Barnabas' romantic interest, the live-in governess Victoria Winters, to temporarily reassess her affection for him.