GOP candidates including Donald Trump and Dr. Ben Carson are expected to battle it out on the main stage at the fourth Republican presidential debate Tuesday night in Milwaukee, Wisconsin. The prime time debate televised by Fox Business Network will be broadcast live from the Milwaukee Theater, and there are a few rule changes this time around.

The main debate beginning at 9 p.m. EST will last two hours and feature front-runner Trump, retired neurosurgeon Carson, Florida Sen. Marco Rubio, Texas Sen. Ted Cruz, Florida Gov. Jeb Bush, businesswoman Carly Fiorina, Ohio Gov. John Kasich and Kentucky Sen. Rand Paul. Using four recent polls by Fox News, the Wall Street Journal, Investor’s Business Daily and Quinnipiac, Fox Business Network gave spots in the main debate to any candidate with a polling average of at least 2.5 percent.

Since Trump is still the highest polling candidate, he will stand center-stage for the main debate. Carson will also appear in the center because of an even number of candidates. To Trump’s right will stand Rubio, Bush and Kasich. To Carson’s left will be Cruz, Fiorina and Paul.

Because they failed to make the polling cut, New Jersey Gov. Chris Christie and former Arkansas Gov. Mike Huckabee have been knocked down to the so-called “happy hour” debate at 7 p.m. EST. Christie and Huckabee will be joined by less popular presidential hopefuls, Louisiana Gov. Bobby Jindal and Sen. Rick Santorum. South Carolina Sen. Lindsey Graham and former New York Gov. George Pataki did not qualify for either debate due to their low polling numbers and have been eliminated from both stages.

Here are the regulations for the fourth Republican presidential debate on Nov. 10:

Supplies: The 12 participating candidates can't bring much of anything with them into the debate. That means no cell phones, tablets, notes or props to help illustrate points. But each presidential hopeful will be given a notepad, pen and glass of water. 

Opening statements: Unlike previous debates, participating candidates will not make opening statements, which means there will be more time for arguments and back-and-forth banter, according to Politico.

Questions: Most of the questions will come from a panel of moderators. The earlier debate will be moderated by Fox Business Network anchors Trish Regan and Sandra Smith, as well as the Wall Street Journal's Washington bureau chief, Gerald Seib. The later debate will be moderated by Fox Business Network anchors Maria Bartiromo and Neil Cavuto as well as Wall Street Journal editor-in-chief Gerard Baker.

Subjects: Both the "happy hour" and prime time debates will focus on the economy and other business-related issues facing the United States including job creation, taxes and social security. The 12 participating candidates will be able to express their views on topics ranging from regulation to tax reform and everything in between.

Answer time: Each candidate will have 90 seconds for their initial answer to a question, plus 60 seconds for rebuttals.

Closing statements: Participating candidates will make brief closing statements at the end of the GOP showdown, which will be live streamed for free on