A costume is a set of clothing used for a special purpose or event. Frequently used to describe the clothing worn by actors in plays and films, a costume helps to define the character and identity of the wearer.
From this, costumes have become an essential part of roleplay for many players. As each participant puts on their costume, they become, for the duration of the event, the person they have dressed as.
A costume can be created with a few simple modifications to daily dress. For example, a gown and mortar board turns the wearer into a teacher, while a blouse, tie and pleated skirt creates a schoolgirl uniform. Costumes can be as elaborate or as simple as the wearer desires and is capable of achieving. Special costume can be used to portray a setting in the Roman Empire, the Far East or an Arabian Harem. In some cases, a costume can create a change in gender; a man may turn into a schoolgirl just as a woman can become a male authority figure by wearing a man's business suit or uniform.
Many costumes are made specially for BDSM as well as more general erotic purposes. In many cases, the essential identifying elements of the uniform are present, though great liberties are often taken with the material, the cut, and the ease of removal.
In some instances, a special set of clothing is used for spanking sessions. This may be solely as a signal to indicate "I want a spanking" or the costume itself may be an essential part of the punishment. These costumes are usually designed to humiliate or restrict the movements of the wearer and often provide easy access to the bottom. See spanking clothing for more information.