I've recently written a screenplay about an alien invasion. A friend immediately commented that he found similarities (some general ideas, plot devices) with Half-Life 2: Ep 2, which I haven't even played - and from what he tells me, the similarities are striking.

On the other hand, I think 99% of alien invasion movies follow the same pattern - aliens invade, good guys regroup, good guys strike them with some success, aliens strike back with devastating effects, the heroes somehow save the day. There aren't that many unique plot ideas.

I'm afraid of doing anything with this screenplay, e.g. sending it to competitions, because of the "original work" clause, and the potential of getting sued. I'm 100% sure it's my original work as I've written 100% of it and the characters are original, but there's always the potential of someone saying "wait, that's actually a screen adaptation of Half-Life 2, not your original work".

To complicate things further, I understand plagiarism must include "an intention to deceive". However, there's this company that makes Snakes on a Train, Transmorphers and Alien vs Hunter which clearly intend to deceive and profit from the more famous movie's publicity, and even in that case the response seems mild.

So... what are the limits of plagiarism? Realistically, how concerned should I, a completely unknown and amateur writer, be afraid of submitting a screenplay that could be considered "derivative" to a screenwriting competition? (I'm not asking for legal advice. I know we're not lawyers here. I'm asking for practical advice out of experience). I wouldn't want my screenplay to die unread in my drawer. Thanks!

  • Plagiarism is an ethical issue. The limits to which copying or imitating other work is considered unethical changes over the years. But whatever ethical position you take on it, you can't be sued for plagiarism. (You could be kicked out of university or dismissed from your job for it, though.) What you can get sued for is copyright violation.
    – user16226
    May 23, 2016 at 21:47

3 Answers 3


There is nothing new under the sun, my friend.

If you read TV Tropes you might be forgiven for thinking that all plots are like all other plots. However it is not the plots (there are considered to be only seven or so actual plots anyway) but the characterisations, details, names etc that make your world unique to you.

If you are worried that you have by chance become exactly like something else I would finish writing as if this was the first time anyone had had this idea. Don't worry because you will spend your entire time second guessing yourself. Then in the later revision and editing sessions you could check out the plots you are fearful of having replicated and look for ways to maximise what is different.

If all else fails you could hang a lampshade on the problem and have a witty character bitch about this being the plot to Half Life. If you time this for a point in the plot when some comic relief is needed then you can play this for laughs as well as cultural references especially if another character has never played the game and thinks they are in a some other SciFi movie.

The chances are that by the time you have finished your work that you will have found plenty of ways in which your story is different. It is always easier to fix a finished draft than try and improve something that you've not written yet.

The chances are that if the editor sees value in your work then they will give you feedback on how you can maximise that value and avoid being derivative. Also if a station picks up your script for production the legal team would double check this as part of their job.

  • 1
    Thanks for your comments, I'll follow your advice. One more question though - you say "the legal team would double check this". I had the impression that if you sold a screenplay, part of the contract would say "this is my original work, yada yada" and it would be your problem if someone would sue over the script. So it's the studio's responsibility after they buy it?
    – ggambetta
    Mar 17, 2014 at 10:42
  • 1
    Most of the time, that clause would (or should) include the phrase "to the best of my knowledge". In which case, you cover yourself if there is some unintentional crossover that is a little too close to some other work.
    – Roger
    Mar 17, 2014 at 15:03
  • If a studio is going to sink that much cash into something they will do the groundwork to make sure that they cannot be blamed for anything. That's when they tend to buy the rights to use stuff (like soundtracks from other media) and do a basic double check. Mar 17, 2014 at 17:47

I constantly read books and watch movies that are totally unlike anything that I have ever read or seen before. There is an unlimited wealth of stories that have never been told.

If your story is like "all other" alien invasion stories, then that is because you have seen or read those other stories, learned their underlying schema, and now have applied it unconsciously. I would guess that your story would bore me to tears and that – please! – no movie needs to be made of it, because I, too, have see it several times before. But then we all know that the Hollywood movie industry prefers to make the same five movies over and over again and would probably be deeply grateful for another take on the same boring old idea.

So I wouldn't worry about questions of plagiarism but instead take your friend's comment as an indication that you are on the right track to write a blockbuster movie.

  • 3
    That's an interesting perspective, and you're completely right. I've only recently started writing, so I'm happy to write "something that works" and nothing more - even if it's the same alien invasion story Hollywood always makes. They always make it because it works :) I have no delusions of being an auteur at this point.
    – ggambetta
    Mar 17, 2014 at 10:40
  • I have read over a thousand books this year alone, and have hit that number pretty much every year for the last 20+ years. I read 3-4 hours a night, unless I am super into a book. I haven't read a single book in a VERY long time that I have had the thought that it was unlike anything I've have ever read. The few times I've ever had thoughts like that is if it is a genre I am new to, or back when I was still getting into reading.
    – Ernesto
    Jul 30, 2018 at 12:09

Basically ideas are not "copyrightable," on the expression of ideas is. Even if an idea is repeated, you're not guilty of plagiarism if your presentation is different.

At a tender age, I started constructing a "Sound of Music" knockoff set in France, featuring a prominent family, and a governess for the "six" children in the shadow of World War II. (Prominent families, governesses, and children are recurring themes in literature.) I was afraid of plagiarizing, but needn't have been, because the "dialog" I produced was neither French nor Sound of Music-like but just "American." In the end, I had the governess marry "Uncle Charles" (not the father), not exactly an original twist, after spending World War II with the Maquis guerrillas (this might actually represent a contribution to literature).

So to answer your question, you won't get sued for following a cut and dried "pattern" that "everyone" has seen before. Just make sure that you are writing with your own "voice," (which, like fingerprints, are distinctive). You probably won't even get sued for inadvertent "copying" if it is limited, accidental, and not a pattern. Real plagiarists fall into a certain "mold." Just make sure that you don't.

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