Allen was one of the nation's top high school shooters and was a consensus top-100 recruit for the class of 2018.

[1] He received offers from Campbell, Cincinnati, East Carolina, George Mason, High Point, Illinois, James Madison, Monmouth, Murray State, N.C. State, North Dakota, Nebraska, Ohio State, Old Dominion, Rhode Island, Saint Louis, Tennessee, Texas A&M, VCU, Virginia Tech, and Xavier.

On February 18, 2017, N.C. State announced head coach Mark Gottfried would not be retained following the 2016–17 season.

On December 16, 2017, Allen scored a career-high 13 points (3–4 behind the arc) in 14 minutes against Kansas.

He injured his ankle on February 28, 2019, in a loss to Michigan forcing him to miss the rest of the season.