The workers based near Albany, New York voted 14-0 to join the Communication Workers of America union, the National Labor Relations Board said on Friday.

Blizzard Albany has developed installments of popular video game franchises including Guitar Hero, Call of Duty, and Tony Hawk's Pro Skater.

Activision had argued that Blizzard Albany's entire workforce of about 100 employees, including production workers, should have been involved in the union vote and not only game testers.

The NLRB rejected those claims earlier this week, saying game testers could form their own bargaining unit because they perform a distinct role and have separate supervision and significantly lower wages than other employees.

Activision and the union did not immediately respond to requests for comment.

The company has until next week to object to the election results. If it does not, Activision is legally required to begin bargaining with the union.

Microsoft Corp earlier this year said it would pay $69 billion to acquire Activision, though the deal is facing antitrust scrutiny from U.S. and European regulators.

The vote announced on Friday came after about two dozen employees of Activision unit Raven Software voted to unionize in May. Activision recognized the union and began negotiations in June.

The NLRB has accused Activision of violating federal labor law by threatening retaliation against workers who use social media to discuss working conditions. Activision has denied wrongdoing in the case, which is pending.

(Reporting by Daniel Wiessner in Albany, New York, Editing by Alexia Garamfalvi and Deepa Babington)

By Daniel Wiessner