Almost no one in this business will sign your NDA.

They aren't planning to steal your script. A production company reads hundreds of submissions a year, and somewhere in that pile is something that rhymes with yours. Signing your NDA means betting the company that it doesn't. They won't take that bet, and asking them to marks you as someone who hasn't done this before.

What you get handed instead is a submission release. It says they may already have similar material and you won't sue them over it. Reading that for the first time feels like giving something away. You aren't. It's standard, and signing it is how the meeting happens.

So protect the work somewhere else. Register with the WGA, which timestamps you. Register the copyright, which is the one with teeth, because it opens up statutory damages and attorney's fees. That's the difference between a lawyer taking your call and a lawyer explaining why it isn't worth it. Then keep the paper trail. Dated emails, a submission log, drafts with dates on them.

Sometimes an NDA is normal. When you're being hired. When you're going in on IP they haven't announced. When they send you someone else's script. That one protects their material, not yours, and you sign it. Before you do, check how long it runs, whether it's mutual, and whether it quietly sweeps in ideas you had before you walked in. Ask for a carve-out for your own prior work. That isn't a difficult ask. It's normal.

None of this protects an idea. Copyright doesn't protect ideas either. It protects execution. Which is inconvenient, and also the entire reason the job exists.

Not legal advice, and I'm not your lawyer. For your actual deal, I would get one.