At my Uni I usually go right in without any trouble, the only case I got hassled was a woman's hockey game and that time I kept repeating "I've never had trouble getting into a game before" (true) until they gave up and let me in. (Which doesn't leave me inclined to try again, but I'd already bought a ticket and didn't want to back and stash my gear in my office) I hear in hockey they are really worried about wildcat video streams.
Some of the sports at Cornell are exceptionally laid back. We are one of a few schools that plays sprint football which is 100% the same as regular football except players have to weigh less than 178 lbs [1], I know the head coach, I know people in the parent's association, they leave the gate unlocked and i go right down to the sidelines.