The powerful FaZe Clan gaming team is suing its most famous member, Tfue ... claiming the 21-year-old has "betrayed" the team and damaged the brand by trying to weasel his way out of their contract.

21-year-old Tfue (real name Turner Tenney) is one of the top gamers in the world -- and has earned MILLIONS of dollars thanks to his dominance in Fortnite.

Earlier this year, Tfue called out FaZe Clan publicly -- painting himself as a victim who was taken advantage of by a big gaming team who pressured a then-20-year-old to sign an unfair contract.

The biggest issue at the time was that Tfue claimed FaZe Clan's contract called for 80% of his brand deals and 50% of his merchandise profits ... and Tfue felt it was unfair.

But now, FaZe Clan is firing back in a lawsuit filed in federal court in New York ... essentially saying boo-hoo, you signed the contract and need to live up to it.

"Though a rookie athlete, Tenney was an adult when he signed his contract," FaZe says ... adding, "An initial rookie contract is a risk that the organization takes; most young players young careers never take off."

In fact, FaZe Clan says they believe Tfue has made more than $20 MILLION in earnings since joining FaZe Clan in April 2018 and he's only forked over $60,000.

FaZe says TFue was just your average "skilled gamer" when they found him -- and they transformed him into a bankable gaming pro.

FaZe says the deal they have in place with Tfue locks him up until 2021 -- and the fact he's trying to bail is complete BS.

FaZe says they recognized Tfue was a star and offered significant bonuses along the way -- including an offer to increase his revenue shares in the company substantially. They also claim they offered Tfue a 7-figure salary ... but Tfue refused to play ball.

Instead, FaZe claims Tfue trashed the company publicly ... violating a non-disparagement clause in his contract.

Now, FaZe is suing for their share of Tfue's earnings -- and to shut him up from divulging confidential information about the Clan.

We spoke with TFue's attorney Bryan Freedman who tells us, "Faze Clan’s lawsuit in New York is a ridiculous and obvious attempt to avoid the consequences of its clear violations of California law"

"Filing the lawsuit in New York is actually an admission that Faze Clan has no defense to these violations of California law. Ask yourself, why is Faze Clan is afraid to litigate its wrongful conduct in California? The answer is obvious. Faze Clan will lose."