After Maverick: how sovereign immunity quietly shields tribal compacts

When the U.S. Supreme Court declined in October 2025 to hear Maverick Gaming's challenge to Washington's tribal gaming framework, tribes across the country hailed it as a landmark victory for sovereignty. It was — but not in the way most headlines suggested. The Court never ruled that Washington's arrangement was constitutional, never blessed tribal sports-betting exclusivity on the merits, and never addressed the equal-protection theory at the heart of Maverick's case. What the tribes won was something subtler and, in many ways, more durable: confirmation that a decades-old procedural doctrine can stop these challenges before they ever reach the substantive questions.

Maverick Gaming, a commercial card-room operator, had argued that Washington's decision to permit sports wagering only at tribal facilities created an unlawful, race-based monopoly. The company sued the state and federal government in 2023, seeking to invalidate the 2020 law and the compacts built on it. But the case foundered not on whether Maverick was right, but on who had to be in the courtroom for the case to proceed at all.

The Rule 19 problem

Under Federal Rule of Civil Procedure 19, some parties are deemed so essential to a dispute that a court cannot fairly resolve it without them. The lower courts found that the Shoalwater Bay Indian Tribe — whose compact Maverick sought to dismantle — was exactly such a "required party." The tribe's legal interests were directly at stake, and no existing defendant could adequately represent them. Ordinarily, the court would simply order the missing party joined. But the Shoalwater Bay Tribe, like every federally recognized tribe, enjoys sovereign immunity and could not be hauled into court against its will.

That created an impasse with only one exit. If a required party cannot be joined, and the case cannot proceed fairly without it, the suit must be dismissed. The Ninth Circuit reached that conclusion unanimously, and the Supreme Court's denial of review left it standing. Maverick's constitutional arguments were never weighed; they were rendered unreachable.

Sovereign immunity did not win the argument. It prevented the argument from ever being had — and for tribal gaming, that distinction is the whole game.

Why a procedural win is more powerful than a merits win

It is tempting to view a decision that dodges the merits as a weaker form of victory. In this context, the opposite is true. A merits ruling, even a favorable one, would have produced a written opinion that future litigants could probe for limits, exceptions and distinguishing facts. A dismissal grounded in sovereign immunity and Rule 19 offers no such foothold. As long as a compacting tribe declines to waive its immunity, any competitor seeking to tear down that tribe's exclusivity through litigation runs into the same wall. The doctrine is not specific to Washington; it travels to every state where exclusivity rests on a tribal compact.

This is why the tribes' celebration was warranted even though the Court said nothing about the constitutionality of their arrangements. The structural reality is that lawsuits aimed at compacts almost always require the affected tribe as a defendant, and that tribe almost always cannot be forced to participate. The result is a kind of standing moat around the compact system — one that does not depend on any court agreeing that exclusivity is good policy or sound constitutional law.

The limits of the shield

The Maverick outcome is powerful, but it is not absolute, and tribes would be unwise to treat it as a permanent guarantee. Several threats sit outside its protection. Congress can legislate; sovereign immunity bars private suits, not federal statutes. Federal agencies remain proper defendants in challenges to their own approvals, so litigation targeting an Interior Department decision rather than a tribe's compact may avoid the Rule 19 trap. And the most disruptive pressure on exclusivity today — federally regulated prediction markets offering sports event contracts — does not attack compacts in court at all. It simply routes around them, claiming a separate federal authorization that owes nothing to state gaming law.

That last point connects Maverick to the broader landscape we cover elsewhere. The same exclusivity the Court left undisturbed in Washington is being tested in a different forum entirely as prediction-market exchanges expand. And where compact negotiations break down rather than getting challenged, the resolution runs through a separate federal channel altogether — the process we explain in our piece on secretarial procedures. Sovereign immunity protects a tribe from being sued over its compact; it does nothing to compel a state to the bargaining table or to police a commodities exchange.

The takeaway

Maverick Gaming will be cited for years, but it should be cited for what it actually held: that tribal sovereign immunity, working through Rule 19, can foreclose competitor challenges to compact-based exclusivity without any court ruling on the merits. For the tribes of Washington — whose framework now stands settled, as our coverage of the state's sportsbook system details — that is a profound source of stability. But it is a shield, not a fortress. The pressures most likely to reshape tribal gaming in the coming years are precisely the ones it was never built to stop. Readers who want the structural background can start with our Legal Guide or browse the Washington directory.