CLEVELAND — Here are a few choice mutterings from the scrum of lawyers outside Courtroom 18B, about the federal judge who summoned them to a closed-door conference on hundreds of opioid lawsuits:

“Grandstander.”

“Pollyanna.”

“Over his head.”

And the chorus: “This is not how we do things!”

Judge Dan Aaron Polster of the Northern District of Ohio has perhaps the most daunting legal challenge in the country: resolving more than 400 federal lawsuits brought by cities, counties and Native American tribes against central figures in the national opioid tragedy, including makers of the prescription painkillers, companies that distribute them, and pharmacy chains that sell them. And he has made it clear that he will not be doing business as usual.

During the first hearing in the case, in early January, the judge informed lawyers that he intended to dispense with legal norms like discovery and would not preside over years of “unraveling complicated conspiracy theories.” Then he ordered them to prepare for settlement discussions immediately.

Not a settlement that would be “just moving money around,” he added, but one that would provide meaningful solutions to a national crisis — by the end of this year.

“I did a little math,” he said, alluding to the rising number of overdoses. “About 150 Americans are going to die today, just today, while we’re meeting.”