I had to look it up, but it seems the league actually passed a rule on the show's selection process, and it is documented here: http://www.nfl.com/news/story/0ap2000000259014/article/owners-pass-hard-knocks-rule-at-nfl-fall-meeting Volunteers are accepted. If nobody volunteers, the league will appoint a team to appear on the show, and they must. The following teams are exempt: 1) First year head coach 2) Made the playoffs at least once in the past 2 seasons 3) Have already appeared on the show, going back 10 seasons I think some of the confusion is from stories that have come out saying a team "turned down" the show. They can't turn it down. They can decline to volunteer, but if they qualify then the league can force them to be on the show. At least, that's how it looks to me.