This changes when, at the urging of his shrink (Elliott Gould), Calvin writes about the young woman who wanders in and out of his slumber. The girl of his dreams literally becomes the girl of his dreams when she appears in his waking life, in his kitchen, as if they’re already a devoted couple.

Her name is Ruby Sparks (Zoe Kazan, Revolutionary Road), and she’s cut from the cloth pattern labeled Adorable Hipster Girlfriend. Having his ideal partner available to him 24/7 inspires an adrenaline rush of prose in Calvin, and he finds that whatever he types about her on the page comes true with the living, breathing version.

It’s as if Weird Science fell in love with Adaptation, and they each went in halfsies on a subscription to McSweeney’s Quarterly Concern.

The best thing about Ruby Sparks, which opens Friday at AMC Quail Springs Mall 24, 2501 W. Memorial, is Ruby herself: both the character and her creator, as Kazan wrote the screenplay for her and Dano, her real-life boyfriend. The clever script is in good hands with married directors Jonathan Dayton and Valerie Faris, who finally work again after their Oscar-winning sleeper hit of 2006, Little Miss Sunshine.

The two films share similarities — quirky but well-tempered characters, an effective score, posters of people running toward the right (see Exhibit A, at right) — but Sparks emits less energy, only some by design.

A section of the film in which Calvin and Ruby visit his mother and stepfather (Annette Bening and Antonio Banderas) is comically out of tone, and Dano fails to rise to the climax’s dark demands, relying on an open mouth to emote while Kazan commands the screen and runs circles around him.

Hers is a performance that traverses many layers, emotions and even languages, and the ultimate reason to see Ruby Sparks. While it may be a sidestep for Dayton and Faris, the film marks a huge leap forward for Kazan.