I don’t know if “open campus” is a practice which other high schools indulge… I know my high school didn’t have it when I was growing up. In brief: Upperclassmen who hit certain GPA and conduct standards are allowed to leave the campus for lunch.
As an incentive, open campus seems to be a double-edged sword; while I believe it does inspire kids to do better in classes, the process seems almost impossible to monitor. Many kids skipping off campus for some Arby’s haven’t truly earned the privilege.