Electronic Labyrinth: THX-1138 4EB is a 1967 social science-fiction short film written and directed by George Lucas[1] while he attended the University of Southern California's film school. The short was reworked as the 1971 theatrical feature THX 1138.

In 2010, this film was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant".[3]

In an underground city in a dystopian future, the protagonist, whose name is "THX 1138 4EB", is shown running through passageways and enclosed spaces. It is soon discovered that THX is escaping his community. The government uses computers and cameras to track down THX and attempt to stop him; however, they fail. He escapes by breaking through a door and runs off into the sunset. The government sends their condolences to YYO 7117, THX's mate, claiming that THX has destroyed himself.

The USC program guide accompanying the film describes it as a "nightmare impression of a world in which a man is trying to escape a computerized world which constantly tracks his movements".[1]

Lucas had had an idea for a long time "based on the concept that we live in the future and that you could make a futuristic film using existing stuff".[4] Fellow USC students Matthew Robbins and Walter Murch had a similar idea which Robbins developed into a short treatment,[5] but Robbins and Murch lost interest in the idea, whereas Lucas was keen to persist.[4]