You know nothing, opposing counsel!

In a maneuver straight out of “Game of Thrones,” a Westeros-obsessed Staten Island attorney seeks to reinstate the ancient rules of trial by combat to settle a beef with another lawyer and his clients.

“This is a matter of honor,” said Richard Luthmann, 35, whose passing resemblance to Ser Gregor Clegane would make him a formidable opponent in the fighting ring.

Luthmann made his demand in a brief filed in Staten Island Supreme Court on July 21. The legal tangle stems from a 2013 dispute between two investment firms. Luthmann represented the losing side.

But his client disappeared and never paid more than $500,000 in judgments against him. “He’s in the wind, so they said, ‘Let’s whack on his lawyer’s malpractice insurance,’ ” Luthmann said. The opponents in the case filed a suit alleging that Luthmann helped his client hide assets to avoid the payout.

“It’s a baseless claim,” the lawyer said, and it has dragged on for two years of motions and countermotions.

“This is not a lawsuit anymore; this is an absurdity,” he said. “So I will give them ­absurdity in kind.”

In the HBO sword-and-sorcery saga, those accused of crimes can opt for one-on-one fighting in place of a court trial. It’s a legal twist based on historical fact: Trial by combat was a little-used but accepted aspect of English common law.

“The common law of Britain was in effect in New York in 1776,” Luthmann told The Post. “And the Ninth Amendment of the Constitution recognizes the penumbra of those rights.”

So in layman’s terms, “It’s still on the books,” he said.

In his brief, Luthmann ­“demands his common-law right to Trial By Combat,” and after cataloging eight pages’ worth of legal precedent, “respectfully requests that the Court permit the Undersigned to dispatch Plaintiffs and their counsel to the Divine Providence of the Maker.”

Or, to just have the case ­dismissed.

Luthmann said that if his motion is actually granted, he wouldn’t go for the skull-crush move that doomed Oberyn Martell in a gruesome “Game of Thrones” combat trial.

“I’d go clad in the armor of Robert Baratheon, warhammer in hand,” he said.

In a statement, plaintiff’s lawyer Richard Chusid sniffed, “It should be clear that we do not find the brief amusing and, we believe, neither will the court, both from a legal and ethical perspective.”