The union, supported by the Communications Workers of America, represents 34 people in the quality assurance department at Raven Software.
Activision said it was considering the matter. Workers could also seek to hold an election supervised by the National Labor Relations Board (NLRB).
Activision’s stock has been battered in recent months as the company faces multiple accusations of sexual harassment and misconduct, and on Tuesday Microsoft Corp announced plans to acquire the company.
As criticism of Activision Blizzard’s culture has mounted in recent months, workers have banded together to influence the company’s future, including staging a walkout and circulating a petition calling for the removal of chief executive Bobby Kotick.
Unionization has emerged as a goal for some, and workers in other parts of Activision Blizzard are also signing union cards, said Jessica Gonzalez, a former Activision employee, as well as a current employee who spoke on condition of anonymity.
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“I hope that we are able to serve as inspiration and to help guide other parts of Activision Blizzard … that want to follow in our footsteps,” said Onah Rongstad, a quality assurance tester at Raven.
Activision Blizzard said in a statement that it is “carefully reviewing” the request for voluntary recognition.
“While we believe that a direct relationship between the company and its team members delivers the strongest workforce opportunities, we deeply respect the rights of all employees under the law to make their own decisions about whether or not to join a union,” the company said.
If Activision Blizzard does not voluntarily recognize the union, workers plan to seek to hold an election sponsored by the NLRB, Rongstad said.
Workers on Raven’s quality assurance team began striking in December after learning that 12 of their colleagues had been laid off, Rongstad said.
By forming a union, the workers hope to gain more of a say in decision-making at the company as well as help set their working conditions. QA testers at Raven work up to 50- to 60-hour weeks when deadlines are looming, Rongstad said.