There won’t be much earth left to scorch when Hillary Clinton and Donald Trump meet for their third and final debate Wednesday in Nevada, analysts say.

The first two have been free of the usual limits and rules of presidential debates, featuring allegations of sexual assaults and corruption, jousts over bankruptcies and personal insults and, from Trump, a threat to jail a political opponent.

The meet for the final time at 9 p.m. (EDT) in Las Vegas. The format, moderated by Fox News’ Chris Wallace, is slated to last 90 minutes and cover the economy, immigration, the U.S. Supreme Court and “fitness to be president.”

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Here are five important factors to keep in mind as the candidates take the stage:

Will Trump’s use of unsubstantiated charges continue to escalate?

After pulling nearly even with his Democratic foe in September, Trump has fallen back. Clinton generally was seen as faring better in the first debate and, just before the second, stories about Trump’s vulgar and sexually charged comments about women and allegations of groping spurred dozens of elected Republicans to abandon their support. Now, Clinton leads anywhere from 4 to 11 points in national polls.

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After his decline, the Republican has made a slew of unfounded allegations: Clinton is on drugs, international bankers and a “global power structure” are colluding against him, massive voter fraud is about to occur.

“The whole thing is one big fix,” the Republican complained at a recent campaign rally.

In the final face-off, analysts expect a “no-holds barred” approach.

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“I think he’ll throw everything and the kitchen sink at Clinton,” said Jacob Thompson, professor and debate expert at the University of Nevada-Las Vegas, host of the debate.

Thompson says he expects Trump to intensify his “ scorched-earth approach . . . He’s got to bring something new to attract people because what he’s done so far hasn’t helped.”

But after months of a vitriolic campaign and two bruising debates, what’s left to be unveiled, asked University of Cincinnati political scientist David Niven.

“You could see a scorched-earth approach. But how much of the earth is left at this point?” Niven said.

Will Clinton play it cautiously, i.e. the “Rope-a-dope” strategy?

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Rope-a-Dope? It’s a term the late Muhammad Ali coined to describe his tactic when he was ahead: Pretend to be trapped against the ropes, goad your opponent to throw ineffective and tiring punches. With a lead in the polls, some strategists expect Clinton to do much the same, concentrating on avoiding big mistakes.

“If I were advising Hillary Clinton, I would say do the following: Play Rope-a-Dope the entire debate, be positive and talk about her agenda. Never hit Trump and when she’s hit, play Rope-a-Dope,” said Michael Caputo, a former communications staffer for the Trump campaign.

“When an inexperienced politician is in a must-win situation, they will often overreach. Get too aggressive. Step in a little too close,” Caputo said. “Hillary Clinton is going to count on that from Donald Trump.”

Will Trump defy the expectations by turning down the temperature?

That’s would some Republican allies would prefer: A repeat of the so-called “Commander in Chief” forum where Trump dialed back the rhetoric. Stop insulting non-participants such as Rosie O’Donnell and instead turn the focus on Clinton’s trustworthiness, her email scandal and her “failed record.”

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Beyond Trump’s theme issues (jobs and immigration), Caputo said the Republican should “calmly draw attention to the many allegations that have come out via WikiLeaks” and the email scandals.

“Make the case that she can’t be trusted and step away,” Caputo said. “Be very much in control of his voice, the placement of [his] body and other nonverbal cues.”

Niven said that in the first debate, “every time Hillary pressed one of Trump’s buttons, he couldn’t help but respond.” He added: “I’m wondering if Trump realizes his best asset is letting Hillary talk.”

Body language matters.

The candidates will be behind lecterns (unlike the second debate), but body language is still important.

Trump needs to stay behind the podium and avoid overly aggressive behaviors (he circled around Clinton in the last forum, sparking complaints he “invaded” her space), experts said. But Clinton too has some concerns.

“She need to monitor her nonverbal behavior,” Thompson said. “There might be some wild stuff said on stage. She needs to avoid shaking her head, scowling and frowning.”

Preparation and confidence also play a role in projecting body language, experts said. Whether it’s Clinton versus Trump, Romney versus Obama or George H.W. Bush versus Bill Clinton, Niven said “the candidate who prepares harder and was happier to be there always shines through.”

Will there be a last-minute shocker?

Many a prediction has gone by the wayside in the 2016 presidential campaign. So even in a race marked by surprising developments and far-fetched allegations, don’t rule out more bombshell charges on stage or tactics just offstage. In the last debate, Trump’s campaign tried to seat women who have made sexual-assault allegations against Bill Clinton near the ex-president. Debate officials wouldn’t allow it.