Common Sense Note
Parents need to know that Looper is a sci-fi/time travel/action movie with adult material that's handled in an intelligent and sensitive enough way that older teens should be OK. The violence is mostly of the sci-fi/fantasy variety, with many guns and most characters getting shot at some point (some blood). Potential spoiler alert: A child is shot and killed off screen. The main character has suggested sex with two women; one is shown topless, and there's also kissing and groping. Language is strong but infrequent and includes uses of "f--k" and "s--t." Drugs are an issue; the main character is shown to be addicted to fictitious drugs, but his habit grows worse, and he's shown going through painful withdrawals. Characters learn to be less selfish, and there's a strong female lead.
The main character has suggested offscreen sex with a showgirl who seems to double as a call girl or prostitute. Viewers see them after the fact, and she's seen topless for a few moments. In a later scene, the main character has sex with the female lead. She seduces him and kisses him, and he reciprocates. The sex occurs off screen, and the movie cuts to them in bed afterward.
Plenty of sci-fi/fantasy violence. Just about everyone has a gun, and most characters are shot at some point (in the face, head, heart); many die. Noticeable amounts of blood. In the most shocking sequence (potential spoiler alert!), the older Joe kills a child (off screen), hoping to prevent future disasters. He breaks down and cries afterward. There's a mild suggestion that two other children are in danger. A child throws frightening, supernatural temper tantrums that cause serious harm (in some cases, gorily so). A man's hand is smashed with a hammer. A man is punished via time travel, as parts of his body suddenly disappear (fingers, nose, legs, etc.).
Strong but not constant language includes several uses of "f--k," "a--hole," "ass," "s--t," "hell," "damn," and "p---y." Also, "goddamn," "Jesus Christ," and "oh my God" as exclamations.
The main character -- at two different ages -- begins the story by thinking entirely about himself. But by the end, he's learned to put others first. In a secondary theme, the movie asserts that a child will avoid growing up into an angry criminal if he can be raised by a loving parent.
Drugs / Tobacco /
The main character habitually uses a fictitious eye-drop drug. He's shown waking up after a night of partying and needing more drugs. He goes through painful withdrawals in one scene. In a "flashback" to an alternate timeline, he becomes an addict and is shown graduating to harder drugs, something in a needle. One character smokes a cigarette after sex.