It is also important to note that there is no referee in pickup basketball, and
aggressive defensive moves, such as elbowing, tripping, or blocking
another player’s vision with a hand, is frowned upon. Engaging in rough
contact is a natural part of participating in sports, but there is a way
to do so respectfully. For the benefit of other players on both teams,
it is also considered good etiquette to wear a shirt while playing.