Warning: The following story contains guns, adult themes and strobe lights.

If you go to the theater, you’ve probably seen “trigger warnings” similar to the one above. Posted at entrances, in programs and online, they’re designed to alert patrons to elements of a production they may need to know about in advance — for physical reasons (chemicals used to create fog can harm asthma sufferers and flashing lights may cause seizures) or emotional ones (some people prefer to avoid plays with troubling themes such as suicide).

Trigger warnings have been around for years, but there’s no consensus on how to use them. Theoretically, it makes sense to prepare audiences. But what about plays that are meant to shock us, such as the unexpected gunshot and blood that viewers experience in Broadway’s current re-imagining of “Oklahoma!,” a musical that doesn’t ordinarily involve guns?

Here in Minnesota, theater directors take various approaches. There’s Dark & Stormy Productions, which has never posted a trigger warning in its seven-year history (including for the current show “Dry Powder,” a dark comedy set at a private equity firm). Then there’s the Sheldon Theatre in Red Wing, which warned the heck out of audiences for “Appropriate” last year, with mixed results.

“Every single piece of marketing about ‘Appropriate’ had information about the play containing adult situations, family violence and content that some might find disturbing,” said executive director Bonnie Schock, who staged the Branden Jacobs-Jenkins drama about a family uncovering its violent, racist past. “Our box office was required to inform everyone who purchased a ticket, and it was online. We were very aggressive about trying to ensure everyone was aware, before they walked in the door, that there was content that was not going to be easy.”

Even so, some theatergoers felt blindsided, including, she said, a man who said “we had hurt him somehow and that he was not ready to see this material and, particularly, to experience it with a person he loved.”

Spoiler alert

A recent study in the Clinical Psychological Science journal questioned whether trigger warnings are even useful, partly because people can’t always identify what will trigger them and partly because the warnings themselves may re-trigger people.

Dark & Stormy artistic director Sara Marsh hasn’t used trigger warnings because sensitivities vary widely. “I do a lot of shows that might be candidates for trigger warnings,” Marsh said. “But it’s impossible to anticipate what might trigger any given audience member. Great plays are rooted in tales of morality and ethics and class division, so there could always be something that hits somebody.”

Marsh also worries that warnings scare off the very people who might appreciate the plays they’re being warned about. Her preference is to host post-show talkbacks, direct people to readily available scripts and encourage folks to reach out with specific concerns before buying tickets. (Strobe lights and other elements that can cause physical reactions, she added, definitely warrant the heads-up.)

A similar strategy is used by Old Log Theatre, which issued a general warning about its current production “Five Presidents” containing dialogue that “may offend some of our more sensitive patrons.” Same goes for London’s Royal Court Theatre, which posted information on its website indicating that it doesn’t want to spoil the show by revealing too much, but that it’s happy to discuss content with concerned theatergoers.

Spoilers are a big concern shared by those wary of trigger warnings. The Jungle Theater regularly alerts audiences to adult language and themes, but artistic director Sarah Rasmussen is torn about issuing more detailed warnings.

“I saw that ‘Oklahoma!’ and it was fabulous, one of my favorite things I’ve ever seen,” she said. “But they didn’t even hand out programs until the end, to avoid spoiling surprises. Personally, I want to go to the theater and be surprised, but I’m sensitive that there are other perspectives and needs, and the Jungle wants to be respectful to the needs of audiences.”

‘I don’t want to destroy people’

St. Paul playwright Harrison David Rivers said his views evolved as a result of teaching at Ohio’s Kenyon College this year. The campus arts community debated warnings for a production of Beth Henley’s “Crimes of the Heart,” whose characters are haunted by their mother’s suicide. The debate extended to Rivers’ classroom.

“The students talked about what are best practices in terms of warning people what to expect but making sure they can experience the play as it was intended,” he said. “They came up with a lot of solutions that were less reliant on a trigger warning before the show. They talked about making scripts available beforehand and facilitating conversations about potential themes beforehand so that those with concerns could [talk about them] but those who wanted to experience the play without a heads-up could.”

His Kenyon experience clarified the importance of finding a balance when dealing with difficult subjects. “I don’t want to destroy people. But I do want people to be surprised or taken aback or confronted by something they haven’t had to process before,” he said.

Theater Latté Da warns of “strong language and adult themes” in Rivers’ new play “To Let Go and Fall,” on stage at Minneapolis’ Ritz Theater. The playwright thinks that’s appropriate.

The trickier the material, though, the trickier the company’s decision about issuing warnings. Theatre Coup d’Etat set a June 28 opening for Martin McDonagh’s “The Pillowman,” a play dealing with murder, torture, child neglect, suicide and abuse of foster children. Artistic director James Napoleon Stone, who also acts in the triggering-est show Coup d’Etat has staged, thinks audiences should know exactly what they’re getting into.

“We want to move people, but we don’t want them thrown into emotional turmoil,” Stone said.

Coup d’Etat has issued warnings since its 2011 debut with a confrontational “Macbeth,” evolving from basic “violence and gore” alerts to more focused ones. Stone’s 2015 production of “Equus” contained warnings for nudity and violence as well as psychological themes. Last fall’s “The Tempest” cautioned that some audiences might be upset by the way Prospero talked to his daughter. In the wake of the #MeToo movement, Stone said, Coup d’Etat’s warnings have become more specific about, for instance, violence against women.

Theaters will continue to produce challenging work because one job of the arts is to provoke audiences — to, as Marsh says, “have these conversations in a safe space together.” The question is how much audiences should be prepared before they reach that safe space. Some theatergoers may relish placing trust in the theaters they attend; they want to be surprised. But Stone has heard from others who appreciate knowing exactly what that trust entails.

“I’ve had people leave shows for whatever reason, and both times I got an e-mail saying, ‘Thank you for what you did. I was warned and I thought I could do it, but I couldn’t. I took a shot.’ They wrote to apologize and I said, ‘No, please don’t worry. Take care of yourself. Your well-being is more important than a play,’ ” Stone said.

The artistic director casts a wide net when creating trigger warnings, enlisting the help of cast and crew. “At the end of the day,” he said, “the answer is: Is this something that someone who is not in my shoes might appreciate a warning about?”