Electronic Arts, Microsoft, and Zynga have again voiced their opposition to the Defense of Marriage Act (DOMA). The companies have joined with 275 other United States firms in signing an amicus brief calling on the Supreme Court to repeal the act that defines marriage as between one man and one woman.

"Although marriages are celebrated and recognized under state law, DOMA, a federal law withholding marital benefits from some lawful marriages but not others, requires that employers treat one employee differently from another, when each is married, and each marriage is equally lawful," reads a line from the brief. "DOMA thus impairs employer/employee relations and other business interests."

Other companies signing the brief include Facebook, Amazon, Starbucks, Twitter, The Walt Disney Company, and GameSpot parent company CBS Corporation. No other game companies signed the brief.

EA, Microsoft, and Zynga signed a similar brief last summer. Speaking with GameSpot, EA corporate communications representative Sandy Goldberg explained that this new brief supports a different Supreme Court case, but its goal is the same.

"This brief is similar in nature of course, but supports a different Supreme Court case, this one being United States vs. Windsor. Both have the same implication--that DOMA presents an issue for employers by forcing them to put married employees in two categories which creates regulatory, tax, benefits and morale problems for employers," Goldberg said.

EA last month joined a Human Rights Campaign business coalition to support the repeal of DOMA.

In addition, the publisher will join with the HRC and the Ford Foundation in New York City next week to discuss LGBT issues in games. The half-day event will see attendees discussing the origin of homophobia in games, the difference between exclusive and inclusive language, and how employers can create and promote inclusive work environments for LGBT employees.

Baltimore Ravens linebacker and recent Super Bowl champion Brendon Ayanbadejo will host a fireside chat at the event that will focus on the challenges of creating an inclusive culture, according to a description of the talk.

The Defense of Marriage Act, which was enacted by the federal government in 1996, legally defines marriage as between one man and one woman. The Obama administration since found the act's third section (which contains the definition) unconstitutional and has refused to act upon it.