The actors weren't given scripts but were given guidelines on how to behave or what to discuss in their scenes.
Filming completed in 10 days.
Steven Spielberg had to stop watching the film halfway through on a home screener as he was genuinely spooked by the experience. He completed it in daylight hours the next day and loved it.
Paramount acquired the U.S. rights for $350,000. The film went on to make $193 million worldwide, making this the second most profitable film ever made based on a return of investment. First most profitable is The Blair Witch Project (1999) which cost $22,000 and made $240.5 million.