EA, Zynga, and Microsoft, along with a host of other companies, have banded together against the Defense of Marriage act.
The three gaming entities joined many other US companies in signing an official document stating their opposition.
The 1996 federal law defines marriage as being between one man and one woman, but the Obama administration recently found that portion to be unconstitutional.
Contrary to law in several states, Federal law prevents same sex marriage, which brings about issues regarding 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."
More on the story from our sister site Develop.