In BDSM, Master/slave, M/s or sexual slavery is a relationship in which one individual serves another in an authority-exchange structured relationship. Unlike Dominant / submissive structures found in BDSM in which love is often the core value, service and obedience are often the core values in Master/slave structures. The participants may be of any gender or sexual orientation. The relationship uses the term "slave" because of the association of the term with ownership rights of a master to their slave's body, as property or chattel. While male "masters" will usually be referred to as "Master", whether or not female Masters are referred to as "Master" or "Mistress" may depend upon whether they identify as following the leather subculture or BDSM path, or simply preference. : 27–30

Sexual slavery in a BDSM context is both a sexual fantasy and sexual roleplay. The slave master or mistress might be any person or group, though the majority of such relationships are usually either one dominant, or a committed dominant couple, owning one or more slaves. A sex slave and the owner, and others involved in the relationship, can be of any gender, sexual identity, or orientation. ^[3]

The Master/slave (or Owner / property) relationship is entered into on a consensual basis, without the legal force of historical or modern non-consensual slavery, that is forbidden by the laws of most countries.

The term "sex slave" is used rather than just "slave" because sex is not a necessary component of consensual slavery.

In BDSM, a slave is a specific type of submissive.

Not all submissives are slaves, though all slaves would normally be considered submissive in the relationship.However

some calling themselves 'slave' may only be submissive within a sexual context/activity whilst others are also submissive within other or all aspects of the relationship, 'sex-slave' or 'slave' respectively.

Outside the BDSM community, the relationship of Master/slave is sometimes regarded as a form of consensual sexual slavery. In BDSM, a slave is a specific type of submissive. The Master/slave relationship refers to the relationship between the individuals involved, and does not necessarily require any specific acts, sexual or otherwise, though sexual activity is usually an aspect of the relationship. The sexual aspect could be conventional, and not necessarily BDSM. A slave could also be a masochist or bottom, but this is not always the case.

Some participants regard the relationship as sexual roleplay, while others enter into the relationship on the basis of a highly committed, long-term, submissive lifestyle.

Various forms of symbolism are sometimes used to affirm the owner/slave relationship.

These include wearing the owner's collar, being registered in a slave register, adopting (sometimes legally changing to) a name chosen by the owner, or engaging in a public declaration or ritualized ceremony of some type.

Some people draw up a slave contract that defines the relationship in explicit detail. These contracts may also deal with domestic arrangements (such as cleanliness, home duties) and interpersonal relationship matters (such as issues of deference, language, etc.), besides the sexual arrangements. Typically, they would provide that the Master has the exclusive authority in all matters relating to the body and behavior of the slave, including underwear and other clothing, social relations outside of the arrangement, etc. Although such contracts are not enforceable in the ways legal contracts are, they can be useful for defining in written form the limits of the arrangement between the signatories, and for documenting the consensuality of the relationships they define between them. ^[4]

In some traditional rituals, after signing a slave contract, the commitment to the relationship is celebrated by a collaring ceremony, which can be simple or elaborate, often witnessed by invited friends.

The slave then wears a collar to publicly declare the slave's subjugation and the Master's ownership. Such a collar may be a piece of neckwear, or may be a bracelet or other piece of jewelery that symbolizes slave status. Such a collar is generally not removed except for practical reasons such as medical or security requirements, unless or until the relationship is dissolved; however, a slave is sometimes permitted to wear a more subdued (or less obtrusive) one outside of the home — for example during work or in social situations with people who may otherwise feel uncomfortable.

Slave training is a BDSM activity usually involving a consensual power exchange between two people taking on the roles of a Master or Mistress and a slave. The objective is to change the slave's behavior in a manner that is pleasing to the Master or Mistress, for example to train the slave to follow a set of rules or commands that the Master or Mistress has provided.

Some Masters adopt a holistic approach to the maintenance and long-term development of their slave by using such models as Maslow's hierarchy of needs.

Depending on the relationship, one or more lesson plans may also involve some forms of aversion training.

This could include use of spanking, physical restraints, or clamping to encourage compliance, and to provide the slave with a specific reason to comply.

If the trainee is also a masochist, the aversion to physical pain may be lacking, in which case psychological or emotional discomfort may be employed to create the unpleasant result that punishment requires.

Sexual slavery is a consensual exchange of power by the submissive to the dominant, though the scope of the surrender of discretion may be limited and may be withdrawn at any time.

The types of activities that the sex slave may be expected to perform are usually defined in advance and sometimes spelled out in a slave contract, a document without real value that outlines the desires, limits, and expectations of the parties. The sex slave is often expected to perform sexually, though typically many relationship-oriented dynamics are also clearly negotiated, including clothing, diet, speech restrictions, household affairs and schedules, though the details may be left to the master or mistress. Typically outlined are clear expectations of whether the couple will be monogamous or polyamorous, and if there would be permission or expectation of sexual interaction with other people. Otherwise, a sex slave may be expected to perform many of the same functions that are expected of a slave/submissive, including wearing very revealing clothes, being shared, wearing a slave collar or leash, S&M activities, or bondage. ^[5]

A Master & slave "relationship" is normally a long-term relationship, comparable in duration to normal relationships whereas a Dominant - submissive "relationship" could be of a similar duration or shorter from a few minutes, as in a scene.

Depending on their contract, a sex slave may be traded by the master, facilitated by sex club events, personals in BDSM interest magazines or internet based social networks.

^[0] Commonly, a slave is also said to be a collared slave, though not every slave wears a physical slave collar.

A slave who has satisfied the duration of the negotiated time of service is expected to be released, unless a new duration of service is negotiated.

A slave may at any time withdraw consent to the relationship, effectively nullifying the slave relationship.

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