Available on DVD “10 Years”

It takes a while to sort out who’s who in the gabby high school reunion comedy 10 Years. But once you do, the movie that comes together is an unpretentious, well-acted ensemble piece that doesn’t aspire to be a portentous generational time capsule like The Big Chill, American Graffiti or Diner. But it has enough markers — a grown-up, married white rapper who break dances; a karaoke bar — to suggest an approximate date.

This first feature directed by Jamie Linden, a writer of We Are Marshall and Dear John, who also wrote the screenplay for 10 Years, doesn’t define a generational mood beyond observing that a decade after graduation, several former classmates at Lake Howell High School (named after Linden’s alma mater in Florida) are struggling to grow up.

About 20 revelers converge at a hotel — the reunion was filmed at the Hotel Andaluz in Albuquerque — for a well-lubricated evening of reminiscing and catching up. The movie focuses on about a dozen of them, with Jake (Channing Tatum), the class jock, receiving the most attention.

Tatum, one of the movie’s producers, gives a disarmingly natural and appealing performance as this 28-year-old former high school hero who brings his longtime girlfriend, Jess (Jenna Dewan-Tatum, Tatum’s wife), to the fete. He is contemplating giving her an engagement ring he has stowed in his car’s glove compartment.

When a former sweetheart, Mary (Rosario Dawson), unexpectedly shows up with a husband, Paul (Ron Livingston), there is some awkwardness as the old flame sputters to life. The glum, wordless Paul leaves the party early, as does the beautiful and understanding Jess. But the movie wisely refrains from turning these pangs of desire and regret into shrill melodrama.

One alumnus, Reeves (Oscar Isaac), is a pop star who serenades the assemblage with his biggest hit, a sweet folk-pop love song inspired by the demure, hesitant Elise (Kate Mara), his secret high school crush. She is not into pop music and is only vaguely aware of his renown. The rootless, itinerant life he describes to her is a lonely existence, and although they have chemistry, she resists jumping into his arms.

Other characters regress alarmingly. The competitive buddies Marty (Justin Long) and A J (Max Minghella) vie for the attention of the radiant Anna (Lynn Collins), a sultry beauty who arrives in a fur stole, and end up making fools of themselves when they play a childish prank. Once their defenses are down, these three are not as they first presented themselves to be.

The most badly behaved of the group, Cully (Chris Pratt), was the class bully, who ostentatiously apologizes to those he teased, especially Peter (Aaron Yoo), a nerd he used to torment with homophobic remarks and who cringes at the sight of him. Then Cully repeats his ugly pattern while drinking himself into oblivion as his embarrassed wife (Ari Graynor) stands by. Stumbling onto the stage, he sings the worst version you’ve ever heard of The Lady in Red.

10 Years settles into a sweet and sad ending, with enough hints of bitterness to keep it from being cloying.