Foil acting.

There’s a term.

You have an audition for a part in a series. The trope of the series is that there are living people and dead people who can communicate with the living people. 

There is a set of leading roles all giving life to this particular show with its particular genre.

Parents are needed for one main character. The need is for the parent to show certain parts of the lead character that will drive the plot. Maybe drive it for one episode, several episodes or a season. 

The parents are a foil.

An excellent example of a movie star being the foil to allow another movie star to take their space is the movie Roman J. Israel, Esq. Colin Farrell knows he is a foil to the complex and unconventional role that Denzel Washington plays. Farrell astutely keeps still, fills the picture of a corporate lawyer and leaves Washington to do all the fancy footwork.

Merriam-Webster says a foil is:  Someone or something that serves as a contrast to another.

The writers want to make a point about this main character and need a foil to contrast and show something specific about them.

Learning how TV and movies are written including tropes, icons, cliches, reveals and more can help you audition more specifically. Can help you fulfill your job in the show.

Not being sure why your character is in the script and worse - thinking it’s more than what it is - can cause you confusion.

Find out what the thing is and not what you think it is.

Or you might get foiled.