EA, Microsoft, and Zynga have joined the fight against the Defense of Marriage act.
The three have banded together with other US companies in jointly signing an Amicus brief- a document of interested but uninvolved parties- stating their opposition.
The 1996 federal law defines marriage as being between one man and one woman, but the Obama administration recently found the third section, which contains the definition, to be unconstituional.
While many states recognise same-sex marriage, Federal law precludes it, which is cause for ample confusion when it comes to employee benefits and tax filing.
This places the signers of the amicus brief, "as employers and enterprises, to unnecessary cost and administrative complexity, and regardless of our business or professional judgment forces us to discriminate against a class of our lawfully-married employees, upon whose welfare and morale our own success in part depends."
The brief argues that while the DOMA was an attempt by congress to provide a uniform rule of eligibility for federal marital benefits, marriage is itself recognized under state law.
This means that Federal law provides benefits to some lawful marriages while withholding them from others, and is therefore a non-uniform rule.
"Employers are obliged to treat one employee spouse differently from another, when each is married, and each marriage is equally lawful," reads the brief.
"The burden of DOMA’s dual regime is keenly felt by enterprises that conduct operations or do business in jurisdictions that authorize or recognize same-sex marriage."
The briefing is being filed in regard to the case of Karen Golinski vs The US Office of Personel Management, in which the plaintif has persued marital benefits for her wife.
A district court found the DOMA unconsitutional, but the case has since been appealed by the Bipartisan Legal Advisory Group.