‘Based on a True Story’ (Except the Parts That Aren’t)

But if someone can convincingly claim that he or she was harmed by what screenwriters made up, that is grounds for a strong defamation suit, said Jean-Paul Jassy, a lawyer who works on media and First Amendment cases in Los Angeles.

“A disclaimer is not a silver bullet,” he said.

“And this is where it gets very tricky with docudramas,” Mr. Jassy added. “A court could say: ‘I understand there are fictionalized elements of your show. But you used a real person’s name, and you presented as fact something that’s false that hurt their reputation.’”

Lawsuits fail more often than not because very few fans of these shows probably believe they are watching history as it literally unfolded. Hollywood has, of course, always amped up the drama when telling — and selling — true stories.

But when shows like “The Crown” become so popular because — at least to some degree — viewers believe they are getting an education, the liberties taken by writers go beyond dramatic license, say those who have a stake in getting the facts straight.

Hugo Vickers, a British journalist who has been fact-checking episodes of “The Crown” for The Sunday Times and is the author of several books about the monarchy, called some of what has transpired over the show’s five seasons “a complete perversion of history.”

“They do it all the time,” Mr. Vickers said. “And they couldn’t care less.”

Netflix added a disclaimer after criticism from high places about the inaccuracies in “The Crown,” including from the famed British actress Judi Dench and former Prime Minister John Major over a scene that depicted an imagined conversation between Mr. Major and Prince Charles about the queen’s possible abdication. But the disclaimer, saying the series is “inspired by real events,” appeared not on the show itself but rather on its press materials and in the trailer, which aired on YouTube.

A disclaimer also appears in HBO’s show on the Lakers, saying in part, “This series is a dramatization of certain facts and events.” But Mr. West, the former coach, and some of his players found that wholly insufficient. Through his lawyer, Mr. West demanded an apology from HBO, saying the show “falsely and cruelly” maligned him as an “an out-of-control, intoxicated rage-aholic.”