With the dean at Princeton University breathing down his neck, threatening to expel him if he doesn't stop his online gambling affiliate business, graduate student Richie Furst (Justin Timberlake) decides to bet his entire $17,000 savings in a last-ditch effort to pay for his tuition. When he is defrauded out of his money, he hops a plane to Costa Rica, intending to confront Midnight Black online casino king Ivan Block (Ben Affleck) about the issue. To Richie's surprise, Block is receptive to his complaint, immediately reimburses him for the lost money, and offers him a job worth seven figures. It is an invitation Richie can't refuse, but, as weeks turn to months and he gets a first-hand look at his boss' dirty dealings, it becomes clear he wouldn't be able to walk away even if he wanted to. Bringing added pressure to the equation, FBI Agent Shavers (Anthony Mackie) has begun sniffing around, intent on capturing Block and wanting Richie to assist in luring him back to U.S. jurisdiction.

Ivan Block isn't the only one running a counterfeit operation in "Runner Runner"—so is the film itself. Directing from a ceaselessly pedestrian screenplay by Brian Koppelman and David Levien (2009's "The Girlfriend Experience"), Brad Furman (2011's "The Lincoln Lawyer") is at a loss in how to bring a shine to a luster-free star vehicle that fails at intrigue and depth. Delivering absolutely zero insight into the world of online gambling, the film doesn't concern itself with teaching the rules of poker, blackjack and Texas Hold 'Em, nor depicting the process of playing the games. 2008's cool, chic, informative card-counting drama "21," this is not, and the further "Runner Runner" bumbles along, the more synthetic it appears.

As a thriller, the film is languidly paced and predictable, low on threat or narrative momentum. As a character drama, it is superficial and two dimensional, the people onscreen either stick-figure constructs or too wishy-washy to make an impression. Joining Richie in the midst of his own gambling schemes without properly establishing him as the least bit sympathetic, the story proceeds to follow him as he makes a series of unwise decisions and demonstrates no palpable traits that would lead one to want to actively follow or care about him. He may be the movie's appointed hero, but he is none too heroic. Or charismatic. Or interesting. Or, well, much of anything outside of greedy.

Unless he has a fully formed character to portray, usually from a filmmaker with an auteur's vision, Justin Timberlake (2012's "Trouble with the Curve") has a tendency to flounder on the big screen. It isn't that he is a terrible actor, but there is something inherently vanilla and unthreatening about him, his lack of a warm presence doing him no favors when he is called upon to play the lead protagonist. When his role is as thanklessly written as it is here, the performer is hopeless. There are plenty of Hollywood actors who can transcend a weak script. Timberlake isn't one of them. Ben Affleck (2012's "Argo") outclasses his co-star every step of the way as Ivan Block. Affleck can command the screen without having to raise his voice, and it is a good thing since Block is such a restrained antagonistic figure. Save for one scene involving crocodiles, there is little fun to be had in playing this particular bad guy. Gemma Arterton (2013's "Hansel & Gretel: Witch Hunters") is woefully underwritten as Block's promoter and sort-of girlfriend, Rebecca Shafran, who takes a liking to Richie. She is also given some rather dismal dialogue to recite, as when one of her assistants comments favorably on her dress. "Well, you better like it," she replies, "because I'm going to be in it for the rest of the night." Huh?

There is no adequate build to anything in "Runner Runner." Instead of an escalation in the action or goings-on, the film segues from scene to scene with the same dull, uninspired rhythm until, finally, it finds itself in the final scene. Yes, there is a double-cross of some sort, followed by a painful, babbling, hypocritically moralistic lecture Richie gives to Block that puts the final asinine flourish on a movie that irksomely makes its home in the land of offensive mediocrity. Were it not for some exotic Puerto Rican scenery courtesy of director of photography Mauro Fiore (2011's "Real Steel") and a solitary effective heart-to-heart late in the proceedings between Richie and his gambling addict father, Harry (John Heard), "Runner Runner" would be entirely worthless. Still kind of is.