There might gold in the next video you shoot.  It doesn’t happen often, but occasionally a short with a surprising plot twist or memorable characters becomes the seed for a hit feature-length movie. Perhaps the most famous example is “Peluca,” a 9-minute short made for $500. “Peluca” inspired “Napoleon Dynamite,” a feature that earned more than $100 million.

Other examples of successful features based on short films are “Boogie Nights,” “District 9,” “Half Nelson,” “Sling Blade,” and George Lucas’s  “THX.”

If you’re shooting a documentary of your family’s trip to The Grand Canyon or a music video of a neighbor’s garage band, you probably aren’t in danger of being ripped off.

But suppose you’re making a genre picture—for example, a horror or a thriller—based on an idea that you believe is truly original. Although your immediate work may be a 3-minute video, the ideas contained in it could support a feature.

If you’re worried that showing your short might lead to someone stealing your ideas, consider registering the script with the Writer’s Guild of America.

Doing so is easy. Just save the script as a pdf on your desktop. (It can be as short as one page or as long as War and Peace.) Next, visit https://www.wgawregistry.org/webrss/ There, you’ll find simple directions for uploading your work. The registration process takes about one minute. The fee is $20, which covers your work for five years.

Some moviemakers prefer to copyright their scripts. You can do this online at the United States Copyright Office: http://copyright.gov/eco/  The one-time fee is $35.

Neither registration nor copyright will stop determined thieves from taking your idea. But if that happens, registration or copyright might help you prove that you had the idea first, and that fact might help you win the day in court.