In the twenty-third century, legions of humans have sealed themselves away in a large city, covered in a dome. It's largely an ideal, utopian society with pleasure provided to all residing within its walls. However, this comes at a price -
Life ends at age 30.
Running away from the city is prohibited by law and punishable by death. One of the Sandmen, the enforcers of this law, has upheld it for quite some time - but quickly finds himself disenfranchised with the current system. He begins to sympathize with the beliefs of these "runners," and that there is possibility of life on the outside, and the possibility of growing older than 30. Befriending a girl with similar doubts, the twosome run away from the city with hopes of discovering life on the outside.
From what I've read on the Internet, this movie is up for remake.
Starring: Michael York, Jenny Agutter, Peter Ustinov, Farrah Faucett, Richard Jordan, Roscoe Lee Browne.