Film aficionados are mourning the death of Alan Rickman, an actor who deftly portrayed complex villains that audiences could not help but love.

Rickman, who starred in films such as “Harry Potter,” “Die Hard” and “Love Actually,” died at age 69 on Thursday following a battle with cancer. He was perhaps best known for his role as Severus Snape in “Harry Potter.”

Richard Allen, a TCU film professor, said Rickman’s legacy was based on his ability to portray villains that connected with audiences.

“I’ve always loved his unique style, which is so cool because it’s so understated and so dry and has such emotion underneath,” he said. “He’ll play those villainous characters [so] that you believe he has a heart.”

Allen said the characteristics of an actor’s legacy include the commercial and artistic success he has.

“When we think about the actors that we’ve label as great, all-time actors like Meryl Streep, Katharine Hepburn and Charlie Chaplin, they made films that were commercially successful,” he said. “But they also made films where artistry was more important than commercial success.”

Allen said he would remember the magic Rickman created on screen as Professor Severus Snape in the blockbuster Harry Potter films. But he said what made Rickman perfect for this “villainous” role was his ability to make the audience love him.

“You’re able to watch Snape all that time and go, ‘Oh, he’s the bad guy, but is he?’” Allen said.

Allen said Rickman’s role in “Love Actually,” showed the unique ability the actor had. Rickman played opposite of Emma Thompson and Heike Makatsch, portraying a married managing director of a design agency who, in the beginning, has an affair with his new secretary and later returns to his wife, ruining his marriage and family.

“He plays a character that you really want to hate, but you know he’s feeling real pain over his decisions,” Allen said. “He really makes that character three-dimensional, so at the end, I think you’re supposed to be happy when he comes back.”

Allen said there are actors that can perform as he did, but, for Rickman, the roles played by those actors will never be replicated.

“What’s great about the characters that these actors play is that no one will replace them,” Allen said. “He’s one of those people.”