Pain/torture play falls within the realm of mutual satisfaction and agreement whether it is hair pulling, light slapping/spanking, rough fucking or the very intense flogging/rape play etc. Every sub has its own range of pain tolerance and pain/torture play should be within the boundaries of sub's pain threshold. This meaning, the pain does not completely overwhelm the sub and create panic within an encounter.
As a sub gains more confidence and experience, he would want/crave more intensity into the a pain/torture play session. In this situation, pain play can follow a punishment/reward structure. It could be a simple order of telling the sub not to cum while being continuously pleasured. Subs that violate the rules will get 'punish' in the context of play. During this type of play, a sub will be thinking whether he can take anymore of this but on the other hand, will want to endure for Master's satisfaction and to ensure fulfillment to the role as a sub. This situation is also ideal to slowly expand on a sub's pain treshold and to introduce the concept of pain without pleasure that is punishment.
When a sub is in a longer term relationships, it is important to create a deeper punishment/reward structure. Here there is still pain play but also pure punishment. Though short of being owned, a slave at this point still needs to be happy and must desire to continue in such longer term arrangement. As a Master, you are taking time to train a slave and the slave should take the training seriously to show his commitment. In this case, it is imperative that Master sets more rules for the slave. Breaking of these rules will lead to punishment. Here the idea is to keep the slave happy with pain play and to show the Master's right/dominance in the form of administering punishment on a slave.
Punishment is not meant to be pleasurable for a slave. It is use to emphasize a Master's displeasure and there should be no reward after punishment. Rewards are given to enforce positive behaviour and actions. Punishment is for disobedience. In order for punishment to be of meaning, it should be set out clear what are Master's expectation and the appropriate punishment proportion to the offence and severity of each case. The punishment is to be hard and intense with no warm up and can include non physical pain.
