Much is on the line for Donald Trump and Hillary Clinton in what is widely anticipated to be the biggest American political event in modern election history. The two presidential candidates will debate one-on-one for the first time, in a commercial-free 90-minute contest centered around the top issues of 2016.

Clinton, 68, and Trump, 70, will be tested like never before, as for an hour-and-a-half, with no breaks, NBC News' Lester Holt pries into their views and policies on foreign and domestic matters. Presented by the Commission on Presidential Debates at Hofstra University in Long Island, New York, all of the questions are entirely up to Holt, but the rules specify that cameras will remain pinned on the candidates with no cutting away from the stage and no microphone adjustments allowed either.

How Holt's autonomy will come into play is uncertain. The Clinton camp has pushed for the veteran reporter to "fact-check" Trump, while the Republican nominee's team says Holt ought to remain silent and neutral, while the candidates themselves take each other to task for misstating the truth.

Americans, and the world, have a bounty of choices as to how they watch the debate, and each channel or network may offer a different experience. Bloomberg TV will offer its own on-screen fact-checking for each candidate, Politico reported Monday, citing spokespeople.