Shirts versus skins (or shirts and skins) is a common form of denoting team affiliations in a pick-up game (an informal sports game); typically when played by males on a public court or field, such as in a city park or schoolyard. The practice involves the members of one team wearing shirts while the ones of the other team don't. This is used in the absence of uniforms.
Use
This simple form of recognition is a regular sight in streetball, street football, ultimate, and other pick-up games. The identification by manner of dress negates the need to remember the division of players among friends, or to learn the faces of strangers in a pickup game. An alternative to the shirts‐skins system when girls are present is the use of pinnies. However, this requires one or more of the participants, or an organiser, to provide the pinnies, which, in any case some players might find uncomfortable‐to‐wear.
The system is most frequently applied to male participants, due to female toplessness taboos. In coed shirts/skins games where these taboos are observed, female players more‐often align exclusively as 'shirts' (for example, 3 females and 9 males, at a pickup basketball court, would team as 6 male 'skins' versus 3 male and 3 female 'shirts'.) Alternatively, or at greater female‐to‐male ratios, female players in pinnies can be recognised by teammates and opponents as 'skins'.