A romantic comedy only partially successful at one-half of that label, "When in Rome" is more tartly humorous than expected, but fails miserably as a love story. The tedious genre clichés arrive at a breakneck pace, from the stock friend characters who stand in a row, spouting advice at the heroine while oohing and aahing on cue, to uncomfortable scenes played out in front of extras with a predisposed interest in the leading lady's life, to purely idiotic misunderstandings and plot complications that could be worked out in a matter of seconds if anyone onscreen was written with half a brain cell. Not stopping there, the film also includes a father (Don Johnson) whose goal in life seems to be to marry off his elder, confident working-woman daughter, one-liner-spouting poker buddies of the male lead, and a doubting, hard-nosed boss (Anjelica Huston) whom the female protagonist must try to impress by pulling off a big company event. Story conventions are to be expected in mainstream rom-coms, but when they are so strictly abided by in this kind of paint-by-numbers fashion—and only serve to support an implausible story and a wafer-thin central relationship—the results are more deflating than swoon-worthy.

Having just found out her ex-boyfriend (Lee Pace) is engaged to someone else on the same night younger sister Joan (Alexis Dziena) announces she is to be married in Rome following a whirlwind two-week romance, Manhattan curator Beth Harper (Kristen Bell) figures marriage simply isn't in the cards for her. "When I find someone who I love more than my work, then I'll know he's the one," she rather wisely muses. Soon after meeting and clicking with best man and sports writer Nick Beamon (Josh Duhamel) at the reception, Beth is crushed when she confuses a drunken cousin for Nick's girlfriend. Snatching a few coins from the mystical Fountain of Love, Beth returns home not realizing that a spell has been put into place where the original owners of the coins fall instantly in love with her. Stalked by painter Antonio (Will Arnett), magician Lance (Jon Heder), model Gale (Dax Shepard), and sausage entrepreneur Al (Danny DeVito), Beth gradually begins to put some stock in the fountain's magical abilities while reconnecting with and falling for Nick. The only problem: one of the coins she took was actually a poker chip that she is convinced is his.

How can Beth tell that Nick genuinely likes her back and isn't under the same spell as the rest of her would-be suitors? Well, maybe because he doesn't act downright crazy and single-mindedly obsessed like the others. Not only that, but if Beth really knew Nick enough to fall in love with him, as the viewer is led to believe, then she would organically know if his reciprocal feelings were authentic. Instead, Beth is turned from an initially bright, put-together young woman into a dimwit who, like the viewer, is jerked around by a strained screenplay credited to David Diamond and David Weissman (2009's "Old Dogs"). Getting-to-know-you substance between Beth and Nick are more often than not traded in for contrived conflicts where one of them misreads a situation or fails to tell the other the truth about something. Meanwhile, other problems stack against them via senseless actions from supporting characters. For example, Beth's assistant and friend Stacy (Kate Micucci) steals all of Beth's coins right after Beth finds out she needs them to end the spell, and it is for no reason other than to pad out the running time. This, then, leads into a slapstick scene where five people climb into the smallest working car imaginable and escort Beth not only to the front door of the Guggenheim (where Stacy is), but straight into the museum's elevator and up to a gala event.

Directed by Mark Steven Johnson (2007's "Ghost Rider"), "When in Rome" is thwarted by a premise and script that treat the audience like a bunch of imbeciles. Perhaps it would be more palatable if the story were treated strictly as a fairy tale, but the film is set in too close an approximation to the real world and never exposes that it knows how ridiculous the plot is. Comedy-wise, things run a bit more smoothly. When maid of honor Beth is given the task of breaking a vase at Joan's wedding, the amount of pieces it shatters into symbolizing the amount of happy years the newly betrothed couple will share, it is predictable but no less humorous when she has trouble even cracking it. Immediately after, Nick's broken grasp of the Italian language amusingly leads to confusion when he offers to translate Beth's reception speech. A scene where the two go to a restaurant called Blackout, where patrons eat in total darkness and a ridiculously upbeat hostess wearing night-vision goggles snoops over conversations, is admittedly original and so daffy it's funny. In just one scene, the enormously enjoyable Kristen Schaal (2009's "Cirque du Freak: The Vampire's Assistant") practically steals the film as said hostess. Keir O'Donnell (2009's "Paul Blart: Mall Cop") also gets great mileage out of a tiny role as Father Dino, an Italian priest with a weakness for gambling who, in one sly moment, practically begs the wedding guests to voice their objections ("Speak now or forever hold your pieces," he finally says, not quite grasping the turn of phrase).

Her first studio picture where she is front-and-center in the lead role, Kristen Bell (2009's "Couples Retreat") is a fresh-faced joy, her natural beauty allowed to shine without lots of caked-on make-up or an attempt to overly glamorize her. Bell is a smart actress, to boot—just watch her in the dearly missed television series "Veronica Mars" for proof—which makes it unfortunate that, as Beth, she is forced to play someone who is guided not by her mind and heart, but by the ramshackle machinations of the plot. It's great that Bell is getting major film roles, but this one is beneath her. As Nick, Josh Duhamel (2009's "Transformers: Revenge of the Fallen") is amiable enough, but stuck within the constraints of being a handsome, bland love interest. Supporting perfs are more memorable, if open to greater exaggeration. As extra-sneaky magician Lance, Jon Heder (2007's "Blades of Glory") is hilarious playing a Criss Angel wannabe who is continually making Beth's jewelry disappear and saying over-the-top things like, "Time flies, but magic flies faster!" Dax Shepard (2008's "Baby Mama") has fun as Gale ("as in 'gale force wind'"), his male-model caricature taking narcissism to a new level. The high point of Danny DeVito's (2006's "Deck the Halls") participation is the sight of him flirtatiously chasing Kristen Bell around a free-standing museum wall. And, as Stacy, Kate Micucci (TV's "Scrubs") is an offbeat delight.

Goofy-good and goofy-bad all at once, "When in Rome" offers occasional laughs to lessen the pain, much to the chagrin of a truly dumb plot and the immature treatment of it. It is not exactly pleasurable to see a movie that assumes the viewer has the IQ of hair, and that is where this one fails so miserably. The biggest offenders, though, are a focal-point romance that feels disingenuous and unlayered, and a string of artificially orchestrated obstacles and character behavior not the least bit convincing. When you are too busy being insulted to get caught up in a film's narrative or root for the lead's happily-ever-after ending, it is a tell-tale sign that trouble is afoot. Veronica Mars would scoff at a movie like "When in Rome," and understandably so.