They have played each other for almost 100 years. They actually call it "The Rivalry". Two of the most successful programs ever 10 miles apart with passionate fan bases. It will be a shame if they aren't fighting each other for ACC championships and the top spots in the NCAA Tournament.
From the Internet:
The rivalry between Duke and UNC (University of North Carolina at Chapel Hill) is intense and often described as a deep-seated hatred by fans, particularly in the context of basketball.While some consider it a friendly rivalry based on respect, others, especially UNC fans, perceive it with more animosity, fueled by perceived class differences and a public vs. private school mentality.
The rivalry is often viewed as a clash between the privileged and the populist, with Duke representing the former and UNC the latter. This perception fuels a strong sense of tribalism and competition among fans.