The Philadelphia Convention Center was ground zero for the cadets and midshipmen Friday night.
The Army Navy rivalry appeared polite during Friday night's gala, but come Saturday, both sides will be in full battle mode.
"We are friends 364 days a year," said Brig. Gen. Tim Trainor. "It is only one day, we are on opposite sides."
"They are brothers in arms, but tomorrow its football. Maybe Sunday I will shake their hands again, but tomorrow, no," said Nathan Pinner, U.S. Naval Academy.
Out of 113 Army Navy games, this is the 84th game played in Philadelphia.
Philadelphia is considered to be like Switzerland for the rivals since it is equal distant between West Point and the Naval Academy.
While the tourist bureau loves the history of the event, they also love the money, and the estimated 50,000 tourists that come here to spend it.
"It is a $35 million economic impact over the three days that the Army Navy is here," said Jack Ferguson, PA Convention Center.
"This game sells out the city every year," says Michele Simpson, Sonesta Hotel.
The Sonesta is almost sold out which is only part of the $35 million guests will spend in the city over the weekend.
Employees have been prepped by calling in extra staff, fully stocking the bars and restaurants, and extending their hours.
"We want to make a really good impression so they come back again," Simpson said.
"It's a tradition," said Jeff Scruggs.
"We come every year," said Doug Bishop.
Thousands of people are pouring into Center City from all over the country to be a part of the 113th Army-Navy Game festivities.
It is a game rooted in deep tradition.
"From the time you show up to the Academy all you hear is beat Army, beat Army," said Midshipman Colin Brutin.
"I know Army is going to win. There is no thinking about it," said Cadet Everett Benson.
The Patriot Games were held Friday morning. It is a series of challenges between the two academies to kick off the weekend.
"It's a battle of brawn and a battle of brains incorporating both to see which academy is truly superior," said Cadet Matt Fitzgerald.
First up was the Rocky Relay, where they race up the art museum steps, followed by a competition to see who could do the most pull-ups in the afternoon.
While the midshipman and cadets will eventually fight together, this weekend it is all about the competition, Army vs. Navy, with the midshipmen winning the last 10 games.
"We're due for a win," said Cadet Benson. "And I think this year is going to be the year."
"We're making it a habit," said Midshipman Ian McGraw. "Keep rolling with it."
"Definitely Navy," said Midshipman Hunter Boly. "There is no chance Army will win."
The vice president and other dignitaries are expected to attend Saturday's game, so if you are going, expect increased security.