Boundaries are usually separated into Hard limits and Soft limits to denote the levels of flexibility for these types of activities within the context of the scene.
Boundaries are often likely to change with most individuals over time as they become more adventurous and trusting with a particular partner.
Hard limits are established and negotiated areas that the top is never to cross during scene play.
Soft limits are things that the bottom has indicated that under normal circumstances they do not wish to do, however, under certain specifically negotiated circumstances these types of play may be permitted provided they are approached delicately by the top.
The concept of a literal no limits slave exists only on paper, never in practical reality. In order to ensure that a Slave is No limits the only way to be absolutely sure is to put them to death and have them obey your command to die, however, in the case they were to actually follow through, the D-type will now have a dead slave instead of a live one, and a dead slave is nothing but a pile of limits as it can't make the coffee, sweep the floor and many other things a typical slave might be useful for. Because of this, many find those that claim to be a no limits slave to be uneducated on the practical parts of existing in an M/s dynamic.
There are, however, slaves that will do nearly anything that would make some people cringe at the casual whimsical mention of their Master without the slave ever batting an eyelash but these are not precisely no limits slaves, and generally those that work so hard to embrace their slavery that they can exist at that level of obedience usually have spent a lot of time doing lots of internal work, know themselves very well and fully recognize their own limitations, however minor those limits might be and are sure to negotiate for those things, recognizing that a failure to do so is a disservice to themselves, the one they serve and the relationship they have together.
Limb Lopping Argument
As a follow up to the no limits slave argument is the hypothetical "Would you chop off a limb at the order of the Master you serve to prove your devotion?" which may or may not include an accusation that the s-type is not a true s-type, to which the sane response of any S-type is "If the Master were to order this slave to be harmed in a permanent and irreversible manner that would reduce the slave's serviceability they would be considered mentally incompetent and it would become the job of the slave to care for the Master until such a time that their mental faculties returned" or "This slave would not serve a Master that would act in a manner or make orders that would fail to provide for the health and well being of the slave".
Pushing boundaries, when done with informed consent and with great care can be a great way to enrich a relationship. Be sure to negotiate well and be very comfortable with a partner before attempting to push boundaries. As with anything new in kink always start low and slow. Pushing boundaries with consent is not the same as a consent violation.
Pushing boundaries, if negotiated for, is often considered ethical unless the scene results in:
- Need for emergency medical treatment
- Need for emergency psychiatric treatment
- Imprisonment by local authorities