The role of the confidant is centered on trust. The character serving this story role should possess some degree of wisdom or experience, be able to offer insights or advice, and have the ability to listen.
Think about the real-life person you confide in. Why do you trust him or her with your innermost doubts, worries, and fears? Is it the fact that you share some common experience with this individual? Perhaps a secret? Or maybe you don’t trust the confidant — not really — but the two of you are into some kind of trouble up to your necks, and this is the only one you can discuss the problem with.
A confidant can be an important character in the story, with possibly a small but key part to play. The confidant may supply the encouragement necessary to get the protagonist through the latter, most challenging, section of the story. And if the confidant becomes a mentor figure, the role may prove quite significant due to the character serving as an instructor instead of merely a listener.
Protagonists and antagonists alike may have their own separate confidants.
In the urban fantasy series, THE DRESDEN FILES, by Jim Butcher, protagonist wizard Harry Dresden has a confidant in the character called Bob, a spirit bound by an ancient curse. Bob is an invaluable resource of instruction on how to cast all sorts of spells, but he’s also someone Harry can talk to and confide in.
In the original STAR TREK television series, Captain Kirk relied on the ship’s doctor, “Bones” McCoy, for counsel and advice. Kirk didn’t always take it, but at least he could talk over his problems.
In the Disney animated film, ALADDIN, the villain Jafar had a confidant in the parrot Iago.
In the movie, THE SOUND OF MUSIC, it was the Reverend Mother at the convent who served as Maria’s confidant, someone she could spill her feelings and fears to when she would talk to no one else about her love for Captain Von Trapp.
And on it goes. There are endless examples from books, television, and film. The confidant is more than simply a sounding board. He or she can bolster motivation within the protagonist and provide the compassion that demonstrates to readers that the protagonist is worth caring about, and worthy of succeeding.