Whenever a new piece of art comes out like movies, comics, books, and video games, many people look at reviews by critics to see if the media in question is good or bad and decide whether it's worth their time and effort to indulge in. However, to convey what works and doesn't work about a film sometimes means revealing certain plot points, elements of certain characters, and how the technical craft in the piece conveys it's story/message. This runs the risk of spoiling a film for someone and forced me to wonder if reviews give away too much information.
The answer to that question varies from person to person, because we should also ask how surprised by a piece of media each person wants to be? To preserve the surprises do some people go as far as avoiding trailers and IMDB pages on a film until release? Do others not care about surprise and actively seek out spoilers online? It's hard to write reviews that completely play to everyone's desires and behaviors, which is why I've compiled a certain set of basic do's and don'ts when it comes to writing reviews.
When writing about a film, you can't be too vague. Just saying it was good or bad isn't enough; you have to tell the audience why you thought it was good or bad. However, reviewers can often get over expressive and give away certain things that should of remained a secret. A good way to avoid this is by describing a character moment and/or plot point, but remaining vague enough that you don't spoil "which" character it is or what "exactly" the plot point was.
For example, let's look at a film like "Fight Club" (spoilers ahead for "Fight Club.") In the film, the film's protagonist (Edward Norton) and his partner Tyler Durden (Brad Pitt) form fight clubs where men let out their aggressive tendencies through fighting. This eventually devolves into an anarchistic movement and the protagonist attempts to stop Tyler from taking it any further. However, it's revealed that Tyler doesn't really exist and was a personality created in the protagonist's head. All of the things Tyler has done has been the protagonist this entire time.
If you read all of that, you can sense that this review gave away too much and ruined a perfectly surprising twist in the process, but you have to mention the twist in some degree because it's the most memorable part of the film. A better way to describe this is by saying things like "I won't give too much away, but the film features a surprising turn that not only serves as a great twist in its own right, but cements the themes of the film and shows men how their idealized versions of themselves can lead to extremely destructive behavior." Notice how I didn't exactly give away what the twist was, but I described it's importance to the story and the themes it conveys.
By remaining vague you kept it a bit of a mystery, which allows the reader to become interested in seeing the film. Many amateur critics make these mistakes and need to learn the right balance of information. This was never really that much of a problem in the past when critics were trained professionals, but now with the rise of the internet and YouTube every puts out "reviews" without the proper training that goes into righting them (like they say, "everyone's a critic.") The fear of spoilers has lead to people avoiding traditional reviews to the point where, when a piece of media gets released, they just go onto review aggregate sites like Rotten Tomatoes and Metacritic, and look up their review scores.
This is a very limited way of engaging with a film. If you want to read relatively in depth reviews without running the risk of discovering spoilers, then you should start at places like Rotten Tomatoes and Metacritic. However, don't just stop at viewing the score of any given media. Scroll through the collection of reviews they gather and start reading them. These sites are good at collecting reviews from professional reviewers and review sites. The internet is full of content regarding media and some of it doesn't always give spoiler warnings, which is why one must always keep a good eye out and have the knowledge to spot the difference between professionally written reviews and people dumping spoilers online in the guise of a review.
