Jason Sudeikis, Susan Sarandon and thousands of other actors joined screenwriters in Hollywood’s biggest strike in more than six decades.
Actors will not appear in films or promote films during the halt.
The shutdown could affect major films in production, including the Avatar and Gladiator sequels.
The actors join writers who walked out in May over concerns over pay, working conditions and the industry’s use of artificial intelligence (AI).
Brian Cox, lead actor of HBO’s Succession, told the BBC that the strike would last “until the end of the year”.
“The whole streaming thing has changed the paradigm,” the Scottish star told BBC Newscast.
“They’re trying to freeze us out and ground us because there’s a lot of money to be made in streaming and the desire is not to share that with writers or performers.”
Talks over a new contract with studios and streaming giants broke down on Thursday, with the Screen Actors Guild (SAG) accusing the Alliance of Motion Picture and Television Producers (AMPTP) of being “unwilling to deliver a fair deal”.
About 160,000 artists went on strike at midnight, joining 11,500 members of the Writers Guild of America (WGA) who walked out on May 2.
On Friday afternoon, union members and their supporters gathered outside the offices of major studios and streaming services in Los Angeles, New York and other cities.
The performances were supported by some of the biggest celebrities in the film and television business, including the stars of the Oppenheimer film who walked the red carpet Thursday night.
Both guilds want studios and streaming services to pay better wages, increased royalties, higher contributions to their pension and health plans, and protections about the use of AI in the industry.
Productions likely to be affected include sequels to the Avatar, Deadpool and Gladiator franchises, as well as upcoming seasons of shows such as Stranger Things, Family Guy and The Simpsons.
Events including red-carpet premieres, promotional interviews, the Emmys and Comic-Con have already been canceled, rescheduled or scaled back.
The strike action is partly driven by the uneasy transition to the age of digital streaming, as well as vast technological changes.
“AI will affect everyone,” Academy Award winner Susan Sarandon told the BBC from a picket line in New York.
“There’s always that feeling that if it’s not fixed now, how will it be fixed in the future?” she said.
“If you don’t have the foresight to put something into the future, you’re screwed. It’s clear that nothing is going to change from the top down, it’s up to us at the bottom.”
Writers and actors complain that they make far less money than they earn, and that their contracts are cut due to inflation.
For actors, pay for individual roles has declined, forcing them to seek multiple roles to earn the same amount as they did a few years ago.
Writing contracts have become shorter and more precarious, often not including payment for writers’ work on revisions or new material.
“We are being victimized by a very greedy organization,” current SAG president Fran Drescher said Thursday. “I was shocked by the way we were treated by the people we were doing business with.”
The failure of negotiations between the unions and the AMPTP marks the first strike in the industry since 1960. In 1980, the last actors’ strike lasted for 10 weeks.
A third union, the Directors Guild of America (DGA), is not participating in the strike after successfully negotiating its own contract in June, but the group said it strongly supports the picketers.
With the strike expected to last for months, cinemas may face problems and viewers will have nothing new to watch bar reality TV and live sports.
In a statement Friday, President Joe Biden said he “believes all workers — including actors — deserve fair pay and benefits.”
“The president supports workers’ right to strike and hopes the parties can reach a mutually beneficial agreement,” spokeswoman Robin Patterson said.
Actors represented by SAG’s sister union in the UK – Equity – must remain in normal employment due to UK employment laws. It also includes the stars of HBO’s House of the Dragon.
However, the union has told US companies that any attempt to move UK production to the UK will be closely monitored.