The Release...

A standard release serves several functions, but it's most basic is to protect the entity that receives your material - a script or a treatment, etc. - against claims that they stole your idea. It does protect you, the writer, to a certain degree in that it acts as a signed agreement that you have sent work. Think of it as a receipt of delivery... with terms.

Agents, directors, actors, producers - anyone that receives screenplays - usually receive a lot of them. There's a good chance that they'll see the same idea more than once from different writers. For instance, scripts about serial killers. There's a ton of them. Some ideas get explored over and over again. Like cop stories. It's, like, 1 in 4. So if one of these entities decide to develop a script from one writer that resembles the idea another writer or writers, they need to be protected. If you were in the same position, wouldn't you want that assurance? Of course you would. As a writer submitting work, it should be reassuring that the person you're submitting is smart and professional.

A release also verifies that a work is yours, that you created it and are responsible for its originality. If anyone comes after you, you take the heat. It keeps you honest.

Ideas are a dime a dozen in Hollywood. Even good ideas are plentiful. It's making that idea work that takes the sweat and craft of a good screenwriter. Ideas in themselves are not copyrightable. You can't copyright a story about a cop investigating a murder. You have to be much more particular. It's the unique way an idea is executed that is copyrightable. The more particular you are, the more it's yours.

Should you sign a standard release? The short answer is a resounding "yes". If you want to be a screenwriter in Hollywood, people have to see your work. If you're too protective, no one will ever know that you have a great screenplay. Sure, there are risks - and the burden of those risks are generally on you. That said, you can minimize some of the risk by checking up on the entity to which you're sending your precious work. Google them. See if they have credits on IMDb. See if they're listed in the latest Hollywood Creative Directory. Make sure there's no article about them in the LA Times or Variety about indictments or evil-doing. All clear? Then send it.