THE STATE SUPREME JUDICIAL COURT reopened the casino legal wars on Friday, ruling that Mohegan Sun can challenge the Massachusetts Gaming Commission’s decision in late 2014 to award a license to Wynn Resorts for a $2.4 billion casino in Everett.

The ruling plunges the Gaming Commission into uncharted waters, and it’s unclear what would happen if Mohegan Sun were to prevail in court. The situation on the ground is very different now from what it was three years ago. Wynn is full-steam-ahead with construction of its casino and plans to open in June 2019. Mohegan Sun, meanwhile, no longer has a casino site; its proposed location at Suffolk Downs is about to be sold to a developer.

A Wynn spokesman said the SJC decision would have no impact on the firm’s construction timetable. Yet Kevin Brown, chairman of the Mohegan Tribal Gaming Authority, indicated the Connecticut tribe will continue its challenge of the license award.

“This decision affirms our belief that the licensing process was flawed, and the decisions of the Massachusetts Gaming Commission are not immune from further review,” Brown said in a statement.

The Gaming Commission had sought to block legal challenges brought by Mohegan Sun and a handful of other parties, arguing that the state’s gambling law specifically states that unsuccessful applicants for licenses “shall not be entitled to any further review” if rejected by the commission.

But the court held that Mohegan Sun was entitled to proceed under a process called certiorari review, which allows court challenges when serious violations are alleged and no other avenue of redress is available. Mohegan Sun has alleged that the commission, in awarding the Boston casino license to Wynn, violated the state gaming law, ignored specific selection criteria, and gave favorable treatment to Wynn.

The SJC decision doesn’t mean that Mohegan Sun will prevail, only that it will get its day in court. The Connecticut casino operator will have to prove that the commission acted illegally or in an “unreasonable, whimsical, capricious, or arbitrary manner.”

Elaine Driscoll, a spokeswoman for the commission, said the agency appreciated the guidance provided by the SJC. “The commission remains fully confident that this complex licensing process was executed in a manner that was comprehensive, fair, and highly transparent,” she said in a statement. “As the commission has repeatedly demonstrated and subsequently validated by every concluded legal action to date, each license award was based solely on a thoughtful, objective and exhaustive evaluation of each gaming proposal. We will continue to vigorously defend our process in trial court and will prove that the commission’s decision-making is firmly guided by the law and strongly grounded in the best interests of the Commonwealth.”

In its ruling, the SJC tossed out similar claims brought by the city of Revere and the International Brotherhood of Electrical Workers because, unlike Mohegan Sun, they were not directly affected by the Gaming Commission’s decision.

The SJC did allow an allegation of Open Meeting Law violations brought by a group of individual citizens to proceed to court. The court, reviewing the record before it, cited two examples that appear to “plausibly allege” violations of the law and other evidence suggesting “additional potential violations of the Open Meeting Law.”