The concept of a “friends with benefits” relationship isn’t uncommon these days. So, hasn’t everyone tried to have a simple, purely sexual relationship with their best friend while dealing with the joy of everyone else finding love, including your dad, who’s now dating your ex?

This is what Adam Franklin (Ashton Kutcher) has to face everyday in the new Ivan Reitman film, “No Strings Attached.” Because neither wants a serious relationship, Adam and friend Dr. Emma Kurtzman (Natalie Portman) decide to have a liaison based on sex. They decide to stop only when someone starts getting deeper feelings. When an inkling of something more starts to grow, will the two become a couple?

Unfortunately, like most other romantic comedies, the plot is extremely predictable. The audience is blatantly aware of how the entire story will play out just by watching the trailers. Whether there’s some sort of formula movie makers go by now or whether film producers underestimate the intelligence of their viewers, “No Strings Attached” requires no thought while viewing it.

Yet, like all movies, “No Strings Attached” is full of both ups and downs. The supporting cast, for instance, greatly adds to the draw of the film. While debating the true meaning of their relationship, Emma and Adam are surrounded by hilarious friends who are the unacknowledged stars of the film. Emma’s posse includes “Chelsea Lately” comedian Guy Branum and “The Office” star Mindy Kaling, while Adam gets advice from the likes of musician Ludacris’s character, Wallace, and Eli, portrayed by Jake Johnson (“Paper Heart”).

Kevin Kline and Cary Elwes, as Adam’s father and Dr. Metzner respectively, also bring the laughs. The supporting cast definitely succeeds in keeping the audience laughing the majority of the time.

Not all of the jokes in “No Strings Attached” go over well, however. While the jokes, more than the plot line, keep the movie going, sometimes they come across as overly vulgar and unnecessary. The gags seem to try too hard to hold the modern viewer’s interest. Between excessive pop culture references and one too many sex jokes, they don’t always work.

Portman’s Emma seems out of place at times too, with an awkwardly uncaring demeanor. That is not to say that Portman did a bad job. After her award-winning work in “Black Swan,” “No Strings Attached” seems too pale in comparison. While the films are not of the same caliber, Portman does succeed in portraying the no-nonsense doctor who proposes the relationship with a hardened exterior.

Known for his work in comedies such as “Dude, Where’s My Car?” and “That 70’s Show,” Ashton Kutcher, too, delivers. Though Adam comes off as overly attached and emotional, Kutcher communicates to the viewers that he’s just a regular, nice guy who just wants to be happy at the end of the day.

The stars and costars of “No Strings Attached” form a stellar cast, but they are marred by a mediocre plotline. Maybe Ivan Reitman, director of the famed “Ghostbusters,” doesn’t have the experience in directing successful romantic comedies. He’s been at the helm of flops like “My Super Ex-Girlfriend” and “Six Days Seven Nights.”

“No Strings Attached” has solid cinematography, with clean shots and safe sequences, and its soundtrack is quite good.

Clearly, the story is nothing new. This summer, the film “Friends with Benefits,” based on Elizabeth Meriwether’s screenplay of the same title, will be released.  The film features a similar plotline to “No Strings Attached and stars Mila Kunis, Justin Timberlake and Emma Stone.

“No Strings Attached” is simply an alright movie. Its cast and some jokes help, but the bland, dragging plot and predictability scar the film. At least there is some good news- if the audience is disappointed with “No Strings Attached,” “Friends with Benefits” sounds like it may be a hit.

Kate MacDonald can be reached at [email protected].