What is real? Are you real?
Yes, most likely you are, and when I say what is real I mean in regard to your book’s setting. We are not here to discuss one of the perplexing philosophical questions mankind has asked.
Your novel, whether is be fantasy, sci-fi, horror, romance etc. can easily be set in the real world. By this I mean it is set on the Earth, during a known time-period (be in present day or the past) and in an actually existing location, such as London, Paris, Texas, Canada and more. Arthur Conan Doyle’s “The Hound of the Baskervilles” is set largely in Dartmoor, Devon, a real world place. Terry Pratchett’s “Mort” is set on the Discworld, not a real world place. However, Terry Pratchett and Neil Gaiman’s “Good Omens” is set in England (mostly) – aka another real place.
The benefits of setting your novel in the real world is that you have an already established world to fill. If you write “Ted stepped into Buckingham Palace, feeling distinctly underdressed in just a shirt and jeans.” it should be a very likely case that the reader should known where and what Buckingham Palace is. They would know he is in London, in England. If you wrote “Ted stepped into The Temple of Por’rsk Rathomire, feeling distinctly underdressed in just a shirt and jeans.” then the reader will not know where he is. It would be likely you would need to go on to either describe where this place is or even what time and world he is in. Obviously this does not mean to say that you should not still describe your locations or settings, on the contrary, you can spend greater detail in how you are describing something as opposed to also needing to include the explanations of the place. The real world adds an ease of description would be the best way to describe this benefit.
As mentioned before, the genre can still be anything you want it to be. While your novel might be set in London 2019, there could be an alien invasion happening at this time, or there is a monster lurking in the dark streets at night. The real world with an extra twist can add to specific situations, such as helplessness or lack of understanding. How would a normal person deal with a spaceship destroying Hull? You don’t have super technology or advanced weapon’s training (well most likely you don’t, I don’t know your life) so the reader can much more easily identify with your characters. Now that is a definite benefit.
Downsides can be that you do have a little less creative input as to your setting. Creating a new world can be a wonderful experience, and a brilliant opportunity to really go to town with new races, species, religions, politics, architecture and more. If you suddenly describe that London is made up entirely of marble pillars and white sandy beaches, then either you will be questioned on your actual knowledge of London, or this is no longer the real world. As with writing in general it is suggested that you write what you know, so if you know a lot about London then it should be easy setting your story in London. If you don’t know anything about London, then probably best to NOT set your story there.
Overall, having a real world setting can allow for a relatable and a more easily describable world, and often a better start for new writers. If you are intimidated by making an entirely new world, then this is the setting for you.