As indicated above, it varies a great deal. When son played, I believe the rule in the ACC was 27 for conference games. However, the actual number was sometimes more than that. Only 27 guys would be active, but injured players and others sometimes traveled as inactive players. There were times when I saw them in the dugout dressed out, even though officially inactive. For non-conference games son's team usually took the full roster. But, other teams that came in for midweek games, especially the smaller schools, often brought far less than their full roster.