Everyone who sees “Admission” will be someone who likes Tina Fey and Paul Rudd. We know this because everyone likes Tina Fey and Paul Rudd. The downside is that everyone will leave “Admission” thinking: That movie was not worthy of Tina Fey and Paul Rudd. Fortunately, it won’t reflect negatively on the stars themselves, who remain likable — and the movie isn’t un-likable, just weak — and we’ll forget the whole thing ever happened.

Fey plays Portia Nathan, a Princeton admissions officer who risks betraying her impartiality when she takes an interest in a bright, odd applicant named Jeremiah (Nat Wolff), whose high school adviser has taken him under his wing. The adviser, John Pressman (Rudd), a world-traveling do-gooder with an adopted African son (Travaris Spears), is relentlessly enthusiastic on Jeremiah’s behalf, and irksome to Portia. She can’t relate to his near-parental concern for the kids, having had her own desires for parenthood squashed by a poor relationship with her mother (Lily Tomlin), a radical feminist who wishes Portia would call her “Susannah” rather than “Mom.”

Lily Tomlin is welcome to play Tina Fey’s mother anytime she likes, and Fey and Rudd (who surprisingly have not been in movie together till now) bring their respective charms to characters who are right in their wheelhouses. There are some pleasant laughs in the film — which was directed by Paul Weitz (“About a Boy,” “American Pie”) and adapted by Karen Croner from Jean Hanff Korelitz’s much more contemplative novel — and even a few sweet moments in the scenes dealing with young potential, the children are our future, etc. But after resisting formulas for most of its running time, the movie succumbs in the last act to some cliches from the rom-com genre, and overstays its welcome before petering out unremarkably.

C+ (1 hr., 47 min.; PG-13, one F-word, some vulgarity.)