Discipline in BDSM is the practice in which the dominant sets rules which the submissive is expected to obey. When rules of expected behaviour are broken, punishment is often used as a means of disciplining. 
In BDSM, rules can be made so that a submissive ("sub") knows how they should behave (so that the dominant is not displeased). Rules can also be for reminding subs of their inferior status, or for training a novice sub. When such rules are broken, whether consciously or unconsciously, punishment is often used as a means of discipline. Punishment itself can be physical (ex. whipping or piercing) or psychological (ex. erotic humiliation through public nudity or golden showers) or a combination of both (ex. through predicament bondage).
The goal of discipline is to teach the sub how they should behave as well as the consequences that may arise as a result of breaking the rules of behavior. By undergoing punishment on breaking the set rules, they learn self-restraint and become better subs. The punishment is generally related to the mistake, and is generally proportionate to the severity and frequency of the mistake. For example, a punishment for speaking out of turn for the first time may be a simple restraint (such as being silenced using a gag). Similarly, the punishment for a nude male sub getting penis erection, despite not being allowed, can be a chastity cage.
The sub may also be given the option of choosing a punishment. For example, for a minor mistake, the punishment can be an option to be either caned on the buttocks or slapped on the cheeks, while for a major mistake the choice for a female sub can be to choose between breast torture and pussy torture.
Punishments done on BDSM submissives, even harsh ones involving severe pain, should not be confused with sadomasochism. S&M involves giving pain/torture to a "sub" for the enjoyment of "sub" and/or "dom". Contrarily, punishments for disciplining are in response to violations of predetermined rules by a sub, or for otherwise displeasing the dominant. However, the commonality is that there can be limits and safeword in both sadomasochism and disciplinary activities.
Punishment is considered a necessary evil in BDSM, as without it, a sub may repeat mistakes and thus not become a proper sub. 'BDSM punishment' is also not 'forced abuse' – in the former a sub must have granted the trainer prior authority to punish and so cannot be termed forced. Punishment should also not be confused with BDSM training which may involve giving pain just for increasing the endurance limit of the sub. Sometimes, disciplining may avoid punishment altogether, and just a hard glance or loud voice from the dominant may be effective.
- Dominance and submission
- Genital torture
- Master/slave (BDSM)
- Predicament bondage
- 16 BDSM Punishments For Effective Behavior Training, Bad Girls Bible, retrieved 3 Feb 2019
- Bound and Shagged: Discipline, Swarthmore College Daily, Oct 2012, retrieved 27 Aug 2017
- Encyclopedia of Social Deviance, page 75, SAGE Publications, 2017 ISBN 9781483364698
- Bill Henkin, Sybil Holiday: Consensual Sadomasochism: How to Talk About It and How to Do It Safely, Page 71. Daedalus Publishing Company, 1996, ISBN 978-1-881943-12-9.
- What is BDSM?, MensXP, October 2015, retrieved 27 August 2017