The first of three presidential debates between the Democratic and Republican nominees, Hillary Clinton and Donald Trump, will be held Monday at Hofstra University in New York.

The debate will last 90 minutes without commercial breaks. NBC’s Nightly News anchor Lester Holt will be the moderator to ask questions.

It would be the first-ever one-on-one debate between the two candidates, and the clash is expected to draw a record 100 million viewers. What can viewers expect to see as the two polar opposites face off against each other?

A WELL-PREPARED CLINTON VS. AN UNPREDICTABLE TRUMP

As a veteran debater, Clinton has more stage experience than most of the presidential candidates in recent history. But she still took a better half of recent weeks preparing for Monday, looking into massive data about Trump’s history and past performances, doing mock debates with her team and preparing to defend possible attacks from the freshly businessman turned politician.

"I do not know which Donald Trump will show up," said Clinton in an August fundraising event in New York.

How would Trump approach the debate, and whether Clinton has any effective plan to tackle his facade will be interesting to watch for.

"Maybe he will try to be presidential and try to convey a gravity that he hasn’t done before or will he come in and try to insult and try to score some points," said Clinton.

Trump, on the other hand, showed little clue if he will stay on message while looking presidential or resort to petty insults and name-calling that had worked to his advantage on the debate stage in the primary season.

He had been on the campaign trail to the various battleground states, paying minimal attention to the materials his team collected for him, and refused to participate in mock debates. But he had been studying videos of Clinton’s previous debate performances "looking for her vulnerabilities," according to The New York Times.

Even if Trump decides to act "presidential," It is unclear whether he can resist the temptation to attack Clinton on personal issues, including her health and her husband’s past infidelities.

But it’s certain he would not give up the opportunities to go after the scandals that had been plaguing the race from day one, like Clinton’s private email server and her relations with big donors.

"I can talk about her deleting emails after she gets a subpoena from Congress and lots of other things," said Trump in a recent interview with Fox News.

NOT ABOUT POLICIES

History has shown that a presidential debate was seldom a contest of which candidate has better policies.

Instead, it’s a show of character and temperament. This was true ever since the very first nationally televised debate between Richard Nixon and John F. Kennedy in 1960. Radio listeners thought the debate had been a tie. However, with a baggy suit and bad makeup exposed by his constant sweating, Nixon was widely deemed loser of the debate by TV viewers in contrast to a well-dressed and poised Kennedy.

Clinton has been widely acknowledged by voters as experienced and competent for the job of president. There’s hardly any doubt about it. She also has been in many one-on-one live debates throughout her long political career, while Trump has never done even one. So it becomes imperative for Clinton to appear experienced, mature and relatable. If Trump can drag her into an angry dog fight and exchange of name-calling, then he would have a better chance.

Being the first female major-party nominee in US history, it would also be intriguing to see how or if Clinton will play the "gender card."

Studies find that gender stereotypes play an important role. It is already a concern how the viewers would perceive the fact that a 6-foot-2-inch (1.88 meters) Trump will tower over a 5-foot-7-inch (1.70 meters) Clinton when they stand together on stage. Research has also found that a man appearing aggressive will likely be perceived positively, while a woman appearing aggressive is mostly received negatively.

If Clinton remains calm and collected when under attack from Trump, and not get defensive or dismissive as she sometimes does during the campaign, she will score a better image among voters. Trump, on the other hand, should avoid his previous sexist rhetoric to ensure viewers wouldn’t become sympathetic towards Clinton.

DIFFERENT EXPECTATIONS

"When I watch her in the debate, she just seems somehow slimy and can just wiggle out from any question or situation," said Brian Grasso, a sophomore at Duke University.

To gain an upper hand, Clinton has to find a way to change the public’s reception of her as a dishonest and untrustworthy establishment politician, which is a difficult job to do.

The expectation for Trump to emerge as the winner of the debate is relatively low. People don’t expect him to speak with lots of substance. He just needs to show voters that he can handle the job as president, and not someone who cannot control his mouth from speaking outrageous things.

The debate will also be a clash of views on whether the country is in decline. Trump had painted America as a dark and desperate place, and Clinton will have to challenge it.

The three major topics announced by the Commission on Presidential Debates are "America’s Direction," "Achieving Prosperity" and "Securing America," which are translated to economy, national security and the candidates’ vision for the country’s future.

Recent bombing attacks in New York and New Jersey, tensions between police and African Americans in Charlotte, North Carolina and Tulsa, Oklahoma, and shootings in Burlington, Washington could all fall in line with Trump’s rhetoric, as he had benefited before from inciting fear among the American public after similar incidents.

"For all his lack of substance, Trump’s showmanship, as ex-TV star, makes him a formidable debate foe," wrote Brian Fallon, a spokesperson for the Clinton campaign.

Trump’s team had urged the candidate to hold his own and stay focused on important themes like economy, anti-terrorism and protection of the country’s borders.

"A man you can bait with a tweet is not a man you can trust with nuclear weapons," Clinton said during her Democratic convention speech.

How Clinton would attempt to get under Trump’s skin in the debate and bait him into losing his temper will be a scene to look out for.