LOS ANGELES (AP) ― Robert Rodriguez deliberately tried to make his latest “Spy Kids” adventure a bit of a stinker.

Rodriguez, who helped usher in the new age of 3-D movies with the franchise’s third installment in 2003, is billing “Spy Kids: All the Time in the World’’ as a 4-D flick, adding scent cards so audiences can follow along on the action with their noses.

Here’s how it works: Viewers are given scratch-and-sniff cards with circles numbered 1 to 8. When a number appears on screen, they rub the corresponding circle on their cards, which give off a whiff matching what the characters are smelling.

Rodriguez calls his gimmick “Aroma-Scope.’’ He tried it out at test screenings and found that children and parents had a good time with it.

“When it came time to do ‘Spy Kids 4,’ I couldn’t just go back and do 3-D like everybody else is now. I had to bring something extra,’’ Rodriguez said. “Just watching my own kids with interactive gaming, you ask them to watch a movie, it just feels so passive to them. I thought, this helps bridge the gap. It’s an interactive thing, almost like playing a game while you’re watching the movie.’’

The idea dates back to John Waters’ 1981 suburban satire “Polyester,” released in “Odorama,” with viewers given similar scratch-and-sniff cards. The 2003 animated tale “Rugrats Go Wild” also used cards to add scent to the picture.

The new “Spy Kids,” opening Friday and playing in both 2-D and 3-D versions, uses its odors (offered in both formats) to complement the story as a retired operative (Jessica Alba) is called back to service to fight a villain who has speeded up time, threatening to bring about a quick end to the world.

She’s kept her vocation a secret from her new husband (Joel McHale), but her step-kids (Rowan Blanchard and Mason Cook) wind up pressed into the action, aided by the now grown-up original spy kids (Alexa Vega and Daryl Sabara) from the first three movies.

The smells from the scratch-and-sniff cards are mostly pleasant. However, with a bit of raunchy humor, including gags about a spy baby’s diapers, viewers should expect at least one off odor.