Under an international copywriter treaty known as the Berne Convention for Protection of Literary and Artistic Works of 1889 (as revised), your script is automatically copyrighted as soon as you write it and signatory countries to are obligated by law to protect this copyright. To indicate copyright ownership of a work, you should place the copyright symbol (©) and year of claim along with your name on the front of the script. For example:
© 2003, John Smith.
In the instance where you feel your copyright has been infringed by someone else, the problem isn’t so much about whether your work is copyright or not, rather it’s about proving that you created the work (and therefore owned the copyright in it) prior to a certain date. So how do you prove you owned copyright prior to a certain date?
In the past it has been quite common for less-learned people (and sometimes companies) to recommend that you mail yourself a copy of your script as a way to protect your copyright. The idea goes that when you receive your script back you don’t open it, and then you are able to use the postmarked date as proof that the work existed prior to a certain date. Unfortunately this is a fallacy, as it’s extremely unlikely such an argument will stack up in court. Why? Because it’s extremely simple to fake and anyone who works in the legal side of copyright knows this. Faking it is as simple as sending yourself and empty, unsealed envelope, then once it comes back, popping your script inside and sealing it. The post office doesn’t care that the envelope’s empty or even that it is unsealed – they will deliver regardless. So you could easily have sent yourself an empty envelope a couple of years ago, rip-off someone’s script, then pop your new script inside the postmarked envelope and voila! You have a sealed, postmarked envelope containing your script. Don’t use this method.
At a basic level, the best way to protect your script is to be very careful who you show it to. Legitimate producers and/or agents will expect to sign a relevant release form to protect them from any suggestion of infringement, and most will not even look at your script without it. Make sure you keep records of everyone you’ve showed the script to and copies of release forms they’ve signed. Be very wary of anyone who suggests release forms are unnecessary.
If you are really paranoid, you should consider registering your script with the Writer’s Guild of America (or the local alternative in your own country). The WGA offer a script registration service which creates a legal date of authorship for you. There is a nominal fee for this service, but complete peace of mind. Visit the WGA web site for more information and online registration.
Finally, remember that whilst you can copyright a script, you cannot copyright an idea. Be extremely careful who you tell your ideas to, because until they are written down in a tangible form (i.e. in a script or treatment) it is open season for all who hear. More information on the concepts in copyright can be found at the US Copyright Office or the UK Patent Office web sites. You can also read the amended text of the Berne Convention on Cornell University’s web site.
You might also want to check out the service from the Worldwide Creators Online Registry, an organisation which offers registration service for creative works in order to act as a kind of “witness” to the date of creation.