LOS ANGELES — Neither a hyper intelligent robot nor Vince Vaughn could save the box office this weekend, which is down 38.5 percent from the same weekend last year, according to Sunday estimates from box office firm Rentrak.

While Neill Blomkamp’s R-rated “Chappie” might have taken the No. 1 spot in its 3,201 theater debut, its modest $13.3 million gross is hardly anything to celebrate.

It’s a career low for Blomkamp, whose previous films “Elysium” and “District 9” debuted at $29.8 and $37.4 million, respectively.

Distributor Sony remains optimistic about its $49 million film about a police robot (voiced by Sharlto Copley) who learns how to think and feel.

“It certainly opened in our realm of expectations for it for the weekend,” said Rory Bruer, Sony’s President of Worldwide Distribution. He noted that the 60 percent male and 57 percent under-30 demographic breakdown was good for the film.

Sony and its subsidiaries have released all three of Blomkamp’s films.

“I certainly believe, like Neill’s other movies, that it’s going to have a really strong multiple and we’re going to come out fine on the movie,” Bruer said.

The R-rated Vince Vaughn comedy “Unfinished Business” fared even worse, opening at No. 10 to a dismal $4.8 million. The $35 million film about a chaotic European business trip also stars Dave Franco and Tom Wilkinson.

In its second weekend in theaters, Will Smith’s “Focus” fell an estimated 46 percent to take second place with $10 million, bringing its domestic total to $34.6 million.