With movies, just like with any form of storytelling, if you don’t have conflict, well, you don’t really have anything. Regrettably, “I Do ... Until I Don’t,” the latest effort from the undeniably talented writer/director Lake Bell, serves as yet another casualty in the long list of films that tried, and ultimately failed, to seduce us with a charming “who’s who” list of cast members to hide the fact that there’s not really anything at stake.

This version of “likeable crew on a ship headed nowhere” sees Bell gather the always reliable Ed Helms, the hilarious Wyatt Cenac, the stunning Amber Heard and a duo of legends in Mary Steenburgen and Paul Reiser for a trio of vignettes focusing on love and marriage that run parallel to one another and occasionally interweave.

All based in the quaint city of Vero Beach, Florida, Bell and Helms play married couple Alice and Noah, whose struggling window blinds business is perpetually on the verge of bankruptcy, and whose marriage has suffered because of it. In an effort to ease their financial stress, Alice volunteers them to be in a documentary being produced by smarmy British filmmaker Vivian (Dolly Wells), who posits that marriage should not be a lifelong commitment, but rather a seven-year contract. Vivian has also enlisted Alice’s bohemian sister Fanny (Heard) and her free-spirited soul mate Zander (Cenac), as well as squabbling middle-aged couple Cybil and Harvey (Steenburgen and Reiser, respectively).

In order to ensure that the theory fueling her documentary materializes into a self-fulfilling prophecy, Vivian attempts to steer the couples toward separation in a myriad of ways: offering financial compensation, capitalizing on their insecurities, evoking jealousies, etc. Although Vivian’s manipulations succeed in exposing, in occasionally hilarious ways, the flaws that exist within each couple, all three duos decide (cue the fuzzy studio audience “awww”) that their relationships are worth fighting for, and that they can’t allow Vivian’s documentary to come to fruition.

Over the years, Bell’s unique style, both visually and comically, has garnered her immense respect among her contemporaries. And, without a doubt, her flair for utilizing creative camera angles to capture fresh slices of life is on display here once again. That, combined with the talented cast, particularly Reiser’s knack for playing the frustrated everyman, results in genuine moments both fun and funny that are nearly enough to trick you into thinking that “I Do” has legs.

Indeed, “I Do” has enough going for it (I defy you not to smile at the montage synced up to the Heart power ballad “Alone”) to ensure that you won’t leave the theater feeling totally slighted. But while it certainly enjoys some of the same triumphs consistently delivered by similarly modeled predecessors — such as “Love, Actually” and “Crazy, Stupid, Love” — “I Do” is more often than not a victim to the inherent problems that plagued star-stuffed, multiple storyline dross like “He’s Just Not That Into You” and “What to Expect When You’re Expecting.”

Time and again, audiences have witnessed films with multiple character arcs suffer from having too much on the agenda and not nearly enough time to cross it all off. That’s ultimately what happens here; instead of getting fully realized three-dimensional characters entrenched in rich, desperate circumstances, we get kinda-sorta fleshed out characters going through motions that never really feel like they really matter.

And while I certainly admire Bell’s obvious intention for her film to combat contemporary cynicism toward marriage and champion the institution, warts and all, the dearth of emotional stakes here (none of the relationships ever truly feel like they’re in jeopardy) results in “I Do” (which is rated R) failing to be the vociferous rallying cry for marriage it could have been, and instead settling for a quiet “amen to that” from the back row.