In SM, torture is generally used to indicate activities that involve pain of some sort. Strictly speaking, torture differs from physical punishment in that a punishment forms part of a disciplinary process resulting from a transgression by the sub. Torture on the other hand is carried out either to demonstrate to the sub their loss of control or because the top is a sadist and enjoys the act of inflicting pain. Torture in the SM context differs from the more general use of the term in that within an SM relationship the torture is (or always should be) consensual.
Many people in the BDSM community define torture as any sort of pain that is inflicted by means other than a beating; a common example is male genitorture. Any technique that is used as physical punishment can be used to torture the victim.
The degree of pain or discomfort inflicted by the top on the sub will very much depend on how much pain the sub can stand. A masochist or pain slut will thrive on a much more severe session than someone who is just into bondage or mild humiliation. Safewords should be used to allow the sub to indicate to the top if a session becomes too much for them. More complex communication protocols can be used to allow the sub to indicate if they can take more severe pain, or if they need time to recover; this can be done without having to come out of role. "No" can mean "beat me harder", while "Please" can mean "I need a rest for a short time". If the sub is gagged, body movements can substitute for the spoken work. Wiggling his/her bum means "Beat me harder", while raising the foot means "I need a rest". The sub can also be given an object to hold; dropping the object is taken as meaning that the sub has used their safeword.
Ways to torture a sub:
- Beating them (see Physical Punishment and Impact play).
- Clamps (nipple clamps, clothes pegs, zippers).
- Pinching and biting.
- Ice play.
- Heat (Wax, Temperature play).
- Suction cups.
- TENS units.
- Knife play.
- Nipple torture.
For a more serious discussion of torture as defined in its broadest context, read the Wikipedia article on torture.