Here’s what to know about the decision.

While the ruling was certainly a setback for prosecutors, several legal observers said on Wednesday that it did not weaken the core of the case, the state racketeering charge that was brought against all of the defendants.

That charge is based on “overt acts” that the indictment says various defendants took in furtherance of the racketeering conspiracy. The judge was explicit in stating that Wednesday’s order does not apply to those acts.

The ruling was not related to a defense effort to disqualify Fani T. Willis, the district attorney of Fulton County, Ga., who is leading the case. A ruling on that matter, which has made headlines for weeks after it was revealed that Ms. Willis had engaged in a romantic relationship with another prosecutor, is expected by the end of the week.

The nine-page ruling on Wednesday took aim at charges asserting that Mr. Trump and other defendants had solicited public officials to break the law by violating their oaths of office. For example, one count against Mr. Trump said that he “unlawfully solicited, requested and importuned” the Georgia secretary of state, Brad Raffensperger, to violate his oath of office by decertifying the election.

The judge said that prosecutors were not specific enough about what violations the defendants were pressuring public officials to commit.

“These six counts contain all the essential elements of the crimes but fail to allege sufficient detail regarding the nature of their commission,” Judge McAfee wrote in his ruling. “They do not give the Defendants enough information to prepare their defenses intelligently, as the Defendants could have violated the Constitution and thus the statute in dozens, if not hundreds, of distinct ways.”

A spokesman for the district attorney’s office declined to comment on the ruling.

Prosecutors could potentially seek to bring the quashed charges again in a way that addresses the court’s concerns, but it was not immediately clear if they would do so.

In a statement, Steven H. Sadow, a lawyer for Mr. Trump, said: “The ruling is a correct application of the law, as the prosecution failed to make specific allegations of any alleged wrongdoing on those counts. The entire prosecution of President Trump is political, constitutes election interference, and should be dismissed.”

One of the six charges that was quashed, Count 28, relates to Mr. Trump’s telephone call to Mr. Raffensperger on Jan. 2, 2021, in which he pressured the secretary of state to “find” him enough votes to overturn the presidential election.

Another charge, Count 38, related to a letter that Mr. Trump sent to Mr. Raffensperger in September 2021, asking him to decertify the Georgia presidential election results or seek similar “legal remedies,” and “announce the true winner.”

Other counts quashed by the judge also related to attempts to pressure public officials. Three counts — listed as Nos. 2, 6 and 23 in the indictment — allege that several defendants broke the law when they urged Georgia lawmakers to appoint pro-Trump electors after Joseph R. Biden won the state.

Count 5 concerned a call that Mr. Trump made to David Ralston, who was then the speaker of the Georgia House. During that conversation Mr. Trump pressed Mr. Ralston to call a special legislative session to appoint new electors.

Mr. Trump and his former personal lawyer, Rudolph W. Giuliani, had faced the most charges, at 13 apiece. They now each face 10 charges in the Georgia case.

Four of the other defendants also face fewer charges now. They include Mark Meadows, the former White House chief of staff, and John Eastman, a legal architect of the plot to deploy fake electors in swing states that Mr. Trump lost.

Two Georgia lawyers allied with the Trump team, Ray Smith III and Robert Cheeley, also saw a reduction in the number of charges they faced.

Anthony Michael Kreis, a law professor at Georgia State University, noted that prosecutors could appeal the judge’s order, or they could put more detailed versions of the challenged charges before a grand jury, which could issue a superseding indictment.

For that reason, and because the racketeering charges are not affected, Mr. Kreis characterized the judge’s order as “a small blip, as opposed to a major catastrophe for the case against Donald Trump and his allies.”

Norman Eisen, who served as special counsel to the House Judiciary Committee during the first Trump impeachment and has voiced support for the Georgia prosecution, agreed. “I think this is a full-steam-ahead signal about the RICO portion of the case,” Mr. Eisen said, using the acronym for Georgia’s version of the Racketeer Influenced and Corrupt Organizations Act.

Defense lawyers, however, saw the ruling as a significant victory for their side. Mr. Smith’s lawyer, Don Samuel, described the judge’s move as “the first step in what we believe will be the complete exoneration of Ray Smith on all counts.”

Also on Wednesday, Gov. Brian Kemp of Georgia, a Republican, signed legislation that will allow a new, Republican-controlled state commission, which has the ability to remove prosecutors, to begin its work. The commission is likely to examine Ms. Willis’s conduct related to her relationship with Nathan Wade, a lawyer she hired as a special prosecutor on the Trump case.

Opponents have said that they intend to go to court to block the commission.