Originality is a concern of a lot of writers, especially when first starting out. Despite pitches being based on “it’s like X met Y and a little bit of Z”, some writers are terrified to be compared to other works in that way. It’s a worry that they’re just some kind of cheap copy of an idea already perfected by another creator.
There’s a lot of approaches to originality and that can be seen in the distribution of tropes that’ve grown over the years. Thanks to TV-tropes, the understanding of various storytelling techniques seem to be ubiquitous. With the advent of the Internet, writers can’t hide as much behind the ignorance of audiences. With enough will and a strong memory, most elements of stories can be seen in other stories.
Thus, some writers reach the point where they don’t worry about originality of ideas. It’s not about the idea, it’s about the presentation to them. The uniqueness of style and the way that an individual creator develops an idea. However, this relies on the fact(?) that all humans are the expressive conclusions of a mixture of differences… rather than there is the possibility that humans can and do express things in similar ways. It’s a large case study to look at. So people fall to anecdotes to comprehend humans as individuals and of course, they would write differently and make different creative decisions than other individuals!
I don’t know whether that is the case, but I understand that it can seem like that.
Anyways, there are times when people specifically make fun of being a knockoff. Here parodies are born. Parodies are usually meant to be sarcastic knockoffs of another’s creation. What’s interesting about parodies is that there are unique parodies that can be extremely funny, but then there are parodies that use heavy tropes to buy a few cheap laughs. Even in the parody genre, there can be knockoffs.
For people who say that there is no such thing as a knockoff, I beg them to look at the movies in the cheap bin at their nearest big box store (Wal-Mart, etc.). In these bins, one can find the most prime example of a knockoff; Disney clones that seem just a little… erm… off.
Another easy example is in products. There is almost always a cheap version of a product in every big box store. For makeup, for cereal, for almost everything. So why is literature considered immune from this human tendency?
A writer shouldn’t be paranoid about using similar ideas that’ve been used in the past, especially if the ideas are general like “space war” or “magic school”. However, that doesn’t mean cross-referencing should be forgotten. Being aware of what ideas are within a work is a good way to develop creative decisions, though this is a preference for the individual writer to make.
Don’t aim for being ‘unique’, but do think about the decisions you are making and why they are right for what you are creating. Be wary of taking any idea/name/element for granted.
Personally, I constantly cross-reference. I don’t just check titles, I scour terms and names and more. It takes up a lot of time, but I wouldn’t be suggesting the points above if I didn’t live them myself.
When I encounter a similarity with a greater known work, I make a hard decision whether to keep the name/element/etc. (and be aware of the similarity) or to change it to something less known.
Of course, I don’t expect to be 100% in this process.
There are always going to be (obscure) works that strangely coincide with our own for whatever reason (collective consciousness?), but those type of occurrences can be fun and intriguing! They’re a lot funner when you actually did the work to be aware of parallels with existing works… and some readers can pick up on those otherwise unseen patterns.
I’ve run into more than a few with my works. Some even happened AFTER I started developing a project and I’ve had to choose to change/keep something in the midst of the creation. It isn’t about being unique, but it is about being aware and making choices for the direction of the story’s presentation.