Spoiler alerts have become to movies what the Surgeon General’s warning became to smoking: a perfunctory caution before ill-advised behavior.

Remember plot twists in movies? The stunning revelations in films such as Psycho, The Crying Game and The Sixth Sense? Good times.

And getting rarer. When was the last time you were surprised by a movie’s plot?

Studios are trying to maintain the mystery: In the ad frenzy promoting Daniel Craig’s final film as James Bond, No Time To Die, trailers exclaimed (and still do) “You won’t believe the ending!”

Perhaps. Unless you read the Wikipedia entry for the movie. It spelled out the ending in detail — on the movie’s opening weekend.

This is the new rule, not the exception, in Hollywood’s click-bait reality. Movie reviews and plot secrets air on social media the day a movie opens, if not before. Some YouTube movie critiques are ad-libbed on cell phones outside the theater that just aired the film.

And it’s not only the ending. The Eternals, Disney’s latest comic-book entry, led all moves this weekend with a respectable $70 million in the U.S. — only in theaters.

But for those who enjoy Marvel’s trademark end-credits for their cameos and plot clues, bad news: Wikipedia listed that as well. Twice, actually: Eternals had a mid-end-credit scene, too. Both were duly described.

This poses a conundrum for an industry that must tease a film without giving away away too much. Studios are already laboring to sell kids on the theatrical experience itself, no small task in a pandemic. That job becomes tougher without intrigue.

So what fate, the movie twist? Already, fans are calling on fellow cinephiles to be more discreet.

Studios are asking reviewers sign agreements that they will not write on social media about a movie before their reviews. And more film reviews and analyses can be found on YouTube with a “NO SPOILERS” guarantee.

But for now, it’s up to the viewer to provide the suspension of disbelief. And surprise.