I had this conversation with someone not too long ago. They were worried, ever so slightly, that they would become so influenced by the ideas of another that if they wrote their idea down, the person who allegedly had the idea first would hunt them down and sue them.
Unless you’re made of stone, you won’t be able to write anything that isn’t in some way influenced by someone. We’re influenced by other people’s ideas the moment we set foot in a school and are told to read a chapter a week of whatever book the teacher drops in front of you.
And so what if your idea is marginally or largely similar to someone else’s? Neil Gaiman wrote The Graveyard Book which even he himself said is The Jungle Book set in a graveyard.
Stephen Moffatt and Mark Gatiss flat out admitted that their version of Sherlock is “fan fiction”.
And how many different versions of Snow White have their been in the past five years alone? Romeo and Juliet was heavily influenced by the legends of Tristan and Isolde, which also influenced the TS Elliot version of King Arthur’s story. Romeo and Juliet has had numerous adaptations, including added and extended scenes.
As long as you don’t do something incredibly stupid like Ella Grant Hutchings and claim that you wrote your story while contacting a dead writer through a Ouija board, you should be fine.
The aspiring writer wasn’t satisfied with this response. They cited an alleged incident wherein J.K. Rowling sued someone over a story that had a wizarding school.
The only majorly publicized lawsuit that I know of was over a genuine act of plagiarism. There was a Russian author who insisted his work was simply a parody of Harry Potter but at close analysis, it turned out this was not the case, so the lawsuit went through. Then there was that noise with the creator of the Harry Potter Lexicon that J.K. Rowling had praised openly, until the creator wanted to publish it shortly after The Deathly Hallows was released. She didn’t authorize the publication and he tried to go behind her back, which didn’t end well.
But there have been stories of wizarding schools before Harry Potter and there will be such tales long after the ink has dried on the next work set in the Potterverse. Also, J.K. Rowling openly admitted that Harry Potter was basically a straight ripoff of Timothy Hunter, from Neil Gaiman’s work. Neil Gaiman knows about this and doesn’t care. Harry Potter itself is still it’s own story and aside from the titular character, 99% of the story is completely original with notable influences.
There really isn’t a lot of grey area when it comes to plagiarism. It is taking a story word for word and passing it off as your own. But even if your idea is remarkably similar to someone else’s, that is not in and of itself the textbook definition of plagiarism.
Furthermore, the reality of lawsuits is that they cost time and money. For someone to sue you, they have to believe it’s worth the time and effort of filling out the paperwork. If they have a lawyer do all that for them, that’s an added expense. Then they have to actually prove beyond a shadow of a doubt that you stole their work, which in and of itself is expensive and time consuming.
At the end of all this, if the judge decides your story was not plagiarized, the person who sues you has to pay all of the court costs and the other associated fees. As much as you like to believe otherwise, you’re probably not worth the effort, yet.
So my advice is to hang your insecurities and the excuses and just write the story. Or don’t write it. Works either way.