There will be no opening statements. President Joe Biden and former President Donald Trump will each have two minutes to answer questions — followed by one-minute rebuttals and responses to the rebuttals. Red lights visible to the candidates will flash when they have five seconds left, and turn solid red when time has expired. And each man’s microphone will be muted when it is not his turn to speak.

The candidates will get a breather during two commercial breaks, according to debate rules provided by CNN to the campaigns and reviewed by The New York Times, but they will be barred from huddling with advisers while off the air.

The first presidential debate of the 2024 cycle is less than two weeks away, and both campaigns are racing to prepare for the first showdown sponsored directly by a television network in more than a generation. The 90-minute contest in Atlanta on June 27 is circled as one of the most consequential moments on this year’s campaign calendar, as Biden and Trump will outline their sharply contrasting visions for the nation, appearing together for the first time since their last debate, in October 2020.

The two men are readying themselves for the debate in ways almost as different as their approaches to the presidency itself. The Biden operation is blocking off much of the final week before the debate, after he returns from Europe and a California fundraising swing, for structured preparations. Trump has long preferred looser conversations, batting around themes, ideas and one-liners more informally among advisers. He held one session at the Republican National Committee headquarters this past week.

Trump and Biden plainly do not like each other. The former president calls the current president the worst in American history. The current president calls his predecessor a wannabe dictator who threatens democracy itself. Four years ago, in their first encounter, Trump trampled over his rival’s talking time — the former president has since admitted privately that he was too aggressive — with Biden scolding him, “Will you shut up, man?”

The rules circulated by CNN warn that this time, “moderators will use all tools at their disposal to enforce timing and ensure a civilized discussion.”

And then there is this: “Microphones will be muted throughout the debate except for the candidate designated to speak.” It is not clear how muted microphones will work in practice — whether the types of memorable moments (Al Gore’s sighs or Barack Obama’s “you’re likable enough” aside to Hillary Clinton) that have defined past debates will be lost entirely.

The candidates will appear without a live audience and at lecterns determined by a coin flip.

For Biden, the preparation process will be overseen by Ron Klain, his first White House chief of staff, who filled the same role for his 2020 debates and his 2012 vice presidential debate. Klain compiles what topics are likely to come up and what prospective answers could be, according to people who have been involved in past planning sessions.

Bruce Reed, the White House deputy chief of staff, has in recent weeks been collecting materials on the two candidates’ policy contrasts for Biden to study. If past is prologue, Biden will use the early meetings to hash out how he wants to answer various questions. In later sessions, he is expected to rehearse with a stand-in opponent.

In 2020, Bob Bauer, a Democratic lawyer who has served as Biden’s personal lawyer and is married to Anita Dunn, a top White House adviser, played the role of Trump; it is unclear if he will do so again in 2024.

“The goal is no surprises,” said Kate Bedingfield, a former White House communications director who was involved in Biden’s 2020 debate preparations. “In some ways, you have to be prepared for the unimaginable. So the aim of the process is to acclimate President Biden to the idea that some really awful things may come out of Donald Trump’s mouth.”

For his part, Trump has never consented to anything resembling traditional, rigorous debate preparation, and this election appears no exception. He has often said that he is at his best when improvising.

“He views his rallies as debate prep,” said Marc Lotter, who was an aide on Trump’s 2020 campaign and now works for a conservative nonprofit group. The challenge for Trump, Lotter said, will be to tighten answers to a time limit. “If they’re literally going to cut your mic, you’ve got to hit your marks,” he said.

Often, campaigns spend the run-up to debates puffing up their opponents and their debating skills. But Trump’s relentless accusations that Biden is mentally diminished have only dampened expectations for the president.

Trump’s close inner circle has so far engaged in fairly limited debate preparation, including the recent meeting at the Republican National Committee headquarters, which included Sens. Marco Rubio of Florida and Eric Schmitt of Missouri.

Jason Miller, a senior Trump adviser who has taken a leading role in organizing the discussions, said that Trump’s speeches demonstrated “elite stamina” and that the former president “does not need to be programmed by staff.”

Trump’s aides are not expected to hold formal role-playing sessions that replicate the debate and include somebody acting as Biden.

“We have conversations,” Chris LaCivita, one of Trump’s campaign managers, explained to reporters this month in Las Vegas. Asked who might stand in for the role of the president, he replied, “Joe Biden is going to play Joe Biden.”

Biden’s team believes it has already won a major victory by persuading the Trump campaign to agree to move the first debate to late June from September. The Biden campaign believes that once voters fully grapple with the prospect of a return to power by Trump, Biden’s lagging poll numbers will improve.

Presidential debates remain singular moments in American campaigns. In 2020, more than 73 million viewers tuned in to the first debate. But increasingly, debates are not just about the live viewership but about the clips packaged afterward, as well as the punditry and expectations in the days beforehand.

Plenty of Democrats are nervous about how Biden will perform. But the president is not said to be one of them.

“I can assure you, Joe Biden is not scared of Donald Trump,” Klain said in an appearance on MSNBC this year.