In some kinds of BDSM play, the "top" (usually a dominant partner) applies sensation to the "bottom"

(usually a submissive partner) by spanking, slapping, pinching, stroking or scratching with fingernails, or using implements like straps, whips, paddles, canes, knives, hot wax, ice, clothespins, bamboo skewers, etc. The sensation of being bound with rope, chains, straps, cling wrap, handcuffs or other materials can also be part of the experience. The tools of BDSM play encompass a wide variety of items from specifically designed implements to ordinary household items, known as "pervertibles."

A pleasurable BDSM experience is thought to depend greatly upon a competent top and the bottom attaining the correct state of mind. Trust and sexual arousal help a person prepare for the intense sensation. Some have even gone so far as to compare adept BDSM play to musical composition and performance, each sensation like a musical note. Likewise, different sensations are combined in different ways to produce the total experience.

Some sensations may be equated to different levels of bodywork and may have the same end result of causing emotional releases and other physical and psychological experiences. This experience is the motivation for many in the BDSM community but is not the only motivating factor. Indeed, a strong minority of BDSM participants (especially "submissives") may well participate in a scene that they do not derive any physical pleasure from. This is done in order to provide their dominant master or mistress with an opportunity to indulge their desires or fetishes.

Dominant behaviour

Three floggers

A dominant person enjoys controlling a submissive person. Reasons for this are said to include demonstrating skill and power, having ownership of another person, and being the object of affection and devotion. Domination may be the fashion in which the dominant feels most comfortable expressing and/or receiving affection. Service-oriented dominants would add that it is obviously useful to have the resources and abilities of another human at their disposal. In addition, many fantasies involve the reversal of traditional roles or constraints, so that men or women who traditionally have powerful roles in contemporary culture may wish to experience submissive roles, while others who normally are responsible for enforcing traditional morality, may wish to experience situations where such limitations do not exist.

Of course, other known possible motives remain to be considered, including pleasure taken not only in sheer power, but in the suffering of others, thrill seeking in risk taking, and self-destructiveness. That is why many in the BDSM community are concerned with establishing the motivations of those involved in an encounter and advise caution in making BDSM connections.

Some dominants and sadists say they are motivated by the desire to give masochists the pain and pleasure desired by them. Thus, the sadist is a pleasure giver and not one primarily seeking gratification from the suffering of others.

 Submissive behaviour

A submissive person is one who, of their own free will, seeks to submit to another.

Submission, by nature, is a twofold phenomena that expresses itself through power. Submissives, no matter what walks of life they may come from, all share the desire to relinquish power to another individual. Their reasons are varied. Some may find the relinquishment of responsibility to another paradoxically liberating.

Yet the paradox between freedom and entrapment is also expressed through the power exchange between dominant and submissive. Though submitting, it is this very submission they desire. Though dominants push their submissives' boundaries, submissives have the power to end play when it progresses too far. This concept is embodied within the safe word.

Thus submissives have varied reasons for their actions, and their sexual role in the realm of BDSM often has no real correlation with who they are outside of play. Precisely who holds the power within the relationship is debatable. It is therefore arguable that despite outward appearances of dominance and submission, a D&S relationship has as much equality between partners as any vanilla relationship.

Tops and bottoms

In BDSM, a top is a partner who takes the role of giver in such acts as bondage, flogging, humiliation, or servitude. The top performs acts such as these upon the bottom, who is the person receiving for the duration of a scene. Although it is easy to assume that a top is dominant and a bottom is submissive, it is not necessarily so.

The top is sometimes the partner who is following instructions, i.e., he tops when, and in the manner, requested by the bottom. A person who applies sensation or control to a bottom, but does so at the bottom's explicit instruction is a service top. Contrast the service top with the pure dominant, who might give orders to a submissive, or otherwise employ physical or psychological techniques of control, but might instruct the submissive to perform the act on him or her.

The same goes for bottoms and submissives. At one end of the continuum is a submissive who enjoys taking orders from a dominant but does not receive any physical stimulation. At the other is a bottom who enjoys the intense physical and psychological stimulation but does not submit to the person delivering them. It should be noted that the bottom is most often the partner who is giving instructions — the top typically tops when, and in the manner, requested by the bottom. However, there is a purist school of BDSM, for whom such "topping from the bottom" is incompatible with the retention of high ethical standards in the relationships wherein BDSM is practised.

Within a sadomasochisic context, submissive is only roughly synonymous with bottom. Others opine that a "submissive" is specifically pursuing a dominant/submissive power-exchange as a key element, whereas a "bottom" may or may not be interested (or even willing) to engage in that exchange. For the latter, some have proposed the "pitcher" and "catcher" (borrowed from baseball terminology) as more neutral terminology, with the "pitcher" delivering the sensation, the instruction, etc; and the "catcher" receiving what is "pitched." These are in contrast to the term slave, which is a situation where the '"submissive" in a TPE or Total Power Exchange relationship gives up all control to their "dominant" not just for a "scene" but for a "24/7" continuing relationship.'

Switching

Some practitioners of BDSM enjoy switching — playing both dominant and submissive roles, either during a single scene or taking on different roles at different occasions with different partners. A switch will be the top on some occasions and the bottom on other occasions. A switch may be in a relationship with someone of the same primary orientation (two dominants, say), so switching provides each partner with an opportunity to realize his or her unsatisfied BDSM desires with others. Some individuals may switch, but may not identify as a switch because they do so infrequently or only under certain circumstances. Sometimes individuals switch in just physical roles (top and bottom), and sometimes individuals may switch completely in emotional roles (dominant and submissive) as well. Some switches only switch from relationship to relationship and will stay in that role for the duration of the relationship.