Which has a better social life for undergraduates: UIC or Rutgers?

Assuming you mean Rutgers–New Brunswick, Rutgers is likely to offer the more built-in undergraduate social life. It has a much larger residential campus culture, frequent student organization events, major athletics, Greek life, and active weekend programming. UIC can absolutely be social, but its commuter-heavy, urban setting means students often need to be more intentional about building a circle.

Rutgers fits a student who wants college life to be highly visible and easy to enter: meeting people in residence halls, attending campus events, joining clubs, going to games, and finding activity on weekends. Its size also means there are communities for nearly every interest, though the multiple-campus layout and bus system can make friendships feel more spread out at first.

UIC suits a student who prefers a city-based experience and is comfortable taking initiative. Its diverse student body, cultural organizations, and access to internships, food, music, and neighborhoods can create a great social life, particularly for students who join organizations early or live on campus. However, many classmates commute or go home after class, so casual campus hangouts and weekend energy are typically less consistent than at Rutgers.

For someone prioritizing the traditional residential college scene and an easier default path to meeting friends outside class, Rutgers has the edge. For someone who values Chicago and would rather create a social life through selected clubs, roommates, and city activities than a single campus-centered scene, UIC may feel more natural.