In Hollywood where actors mostly come in two flavors, rocky-road action heros who say little and sourball fast talkers who profane much, Joseph Gordon-Levitt is quietly carving a caramel chameleon niche of his own.
Whether as the audacious dream-invader in Inception, the rueful hustler with a black hole where his heart should be in Mysterious Skin, or a spurned swain in  Days of Summer, JG-L uses his burnt-sugar eyes to invite and resist viewer sympathy.
In 50/50, Levitt waves you off and pulls you in as Adam, a mild-mannered 27-year-old diagnosed with a rare form of cancer. The title refers to his chances of survival.
In Las Vegas, those are good odds, muses Kyle (Seth Rogen), Adam's wild-mannered buddy. At the hospital, not so much.
Loosely based on the experiences of screenwriter Will Reiser and produced by Rogen (his writing buddy on Da Ali G Show), 50/50 mines absurdist humor from the veins of mortality.
Levitt, the definition of nuance, is touching, funny, and fierce - an unusual combination of moods, but deeply affecting.
In the film directed by Jonathan Levine (The Wackness), Adam is a draw-inside-the-lines kind of guy - the kind who, when out jogging at 5 a.m., stops for traffic lights although there's no traffic at that hour.
Adam is so busy comforting friends and family that he can't take the time to process it himself, a source of the film's most comically moving moments.
He props up his mother (Angelica Huston, heartbreakingly funny), he props up Kyle, he tries to put the best possible face on his diagnosis to his girlfriend, Rachel (Bryce Dallas Howard). When the hospital assigns Adam a psychologist, Katherine (Anna Kendrick), turns out that she is a trainee and he only her third patient. He props her up, too. That is, until she finds her professional footing. In a move that would be considered unprofessional, she speaks to him as a friend rather than a therapist. And she gets through.
Admittedly, the film has its sitcom moments, as when Kyle coaches Adam to use his diagnosis as a way of picking up girls. But Levitt drills deeper than sitcom shale, and the result is beautifully modulated, desperately funny terror. His performance creates the impression of one gracefully dancing through a minefield.
In the film's third act, Adam faces a risky experimental procedure as he navigates his relationship (is it professional? is it personal?) with Katherine.
Playing a novice professional who thinks she has the answers even though she's reading from a cheat sheet, Kendrick is doing a variation on her character from Up in the Air. Yet her performance and timing are utterly original.
In more than one way is the film 50/50: It's half hilarious, half serious; all poignant.
Contact movie critic Carrie Rickey at 215-854-5402 or firstname.lastname@example.org. Read her blog, Flickgrrl, at http://www.philly.com/ flickgrrl.