Hollywood’s video game performers voted to go on strike Thursday after negotiations with game industry giants that began nearly two years ago came to a halt over artificial intelligence protections.

Leaders of the Screen Actors Guild-American Federation of Television and Radio Artists have billed the issues behind the labor dispute — and AI in particular — as an existential crisis for performers. Game voice actors and motion capture artists’ likenesses, they say, could be replicated by AI and used without their consent and without fair compensation.

The union says the unregulated use of AI poses “an equal or even greater threat” to performers in the video game industry than it does in film and television because the capacity to cheaply and easily create convincing digital replicas of performers’ voices is widely available.

“We’re not going to consent to a contract that allows companies to abuse AI to the detriment of our members. Enough is enough. When these companies get serious about offering an agreement our members can live — and work — with, we will be here, ready to negotiate,” SAG-AFTRA President Fran Drescher said in a statement Wednesday. “

Here are five things to know about the strike, which starts at 12:01 a.m. Friday:

Who is covered under the contract?

The agreement covers more than 2,500 “off-camera voiceover performers, on-camera (motion capture, stunt) performers, stunt coordinators, singers, dancers, puppeteers, and background performers,” according to SAG-AFTRA.

Which game companies are involved?

The union had been negotiating with an industry bargaining group consisting of signatory video game companies, including divisions of Activision and Electronic Arts. Those companies are Activision Productions; Blindlight; Disney Character Voices; Electronic Arts; Productions Inc.; Formosa Interactive; Insomniac Games; Take 2 Productions; VoiceWorks Productions; ad WB Games.

The game companies have said that they were negotiating in good faith and had reached tentative agreements “on the vast majority of proposals.”

Not the first time video game actors have gone on strike

Wednesday’s labor action marks the second time SAG-AFTRA’s video game performers have gone on strike. Their first work stoppage, in October 2016, began after more than one year of negotiations failed. The union and video game companies reached a tentative deal 11 months later, in September 2017. At the time, the strike — which helped secure a bonus compensation structure for voice actors and performance capture artists — was the longest in the union’s history, following the merger of Hollywood’s two largest actors unions in 2012.

What are performers asking for?

SAG-AFTRA has said that some of the key issues include securing wages that keep up with inflation, protections around “exploitative uses” of artificial intelligence and safety precautions that account for the strain of physical performances as well as vocal stress. Union negotiators told The Associated Press that they had made gains in bargaining over wages and job safety, but that the game studios refused to “provide an equal level of protection from the dangers of AI for all our members.”

The signatory companies refused to extend AI protections to on-camera performers, the union said.

“They’re saying we’ll protect voiceover performers, but we won’t protect anybody else,” Duncan Crabtree-Ireland, SAG-AFTRA’s executive director, said in an interview last month. “The bottom line is if you have performers working for you, helping create the content that’s in your game, whether it’s voice content, whether it’s stunt work, whether it’s motion work…all of those performers deserve to have their right to have informed consent and fair compensation for the use of their image, their likeness or voice, their performance. It’s that simple.”

AI is the sticking point

Although the unchecked use of artificial intelligence has been a sticking point in talks, voice actors and members of the union negotiating committee have said they are not anti-AI. The performers are worried, however, that unchecked use of AI could provide game makers with a means to displace them — by training an AI to replicate an actor’s voice, or to create a digital replica of their likeness without consent.

Some also argue that AI could also strip less experienced actors of the chance to land smaller background roles, such as non-player characters, where they typically cut their teeth before landing larger roles. The unchecked use of AI, performers say, could also lead to ethical issues if their voices or likenesses are used create content that they do not morally agree with.

SAG-AFTRA created a separate contract in February that covered indie and lower-budget video game projects. The tiered-budget independent interactive media agreement contains some of the protections on AI that video game industry bargaining group rejected.

The union also announced a side deal with AI voice company Replica Studios in January that enables major studios to work with unionized actors to create and license a digital replica of their voice. It also sets terms that allow performers to opt out of having their voices used in perpetuity.

—Sarah Parvini, AP Technology Writer