They work just as hard as men for less pay.

When they complain, they are told they need to generate as much money as men do if they want to get paid as much as men are paid. When they say that’s essentially impossible without more opportunities and promotion, they are told opportunity and promotion will happen once they start producing more money.

This is the narrative at the heart of the gender discrimination lawsuit the United States women’s national soccer team filed on Friday against U.S. Soccer, but in nearly every sport, gender disparities in pay and working conditions are rampant.

Coming just three months before the start of the Women’s World Cup, the litigation immediately became the central plotline for the event and brought to the fore an issue that has increasingly rankled the sports world.

[Eight times women in sports fought for equality.]

In golf last year, the world’s top-ranked woman earned as much as the 33rd-best man. The United States women’s hockey team expected to have a victory tour after winning gold at the Pyeongchang Olympics last year. It didn’t happen. The N.B.A. minimum salary of $1.35 million for a player with one year of experience is higher than the salary cap for an entire W.N.B.A. roster.