This is a guest post by  Mistress Steel. It was part of her Steel’s Chamber Scrolls which is now defunct. Shared with Permission.

The Wall: The Wall is one identification of the limit that the mind and body are physically capable of processing. Some submissives will talk about 'hitting the Wall' or 'White Out'. This is going so far that the mind loses the ability to cope and can dissociate or retreat from reality. A submissive can and may go fetal in this state and it is not something you should ever try to achieve as it can and may have permanent or lasting effects. It is to go beyond the threshold. Some people who experience such a graphic or traumatic event never return but remain essentially lost inside of their mind for the remainder of their lives. This is serious and the only reason I am writing about it is that this threshold is something that it is important to be aware of the existence of. This is especially true if you are new to the BDSM lifestyle and perhaps unaware of the potentials with which you are playing. The human mind is both strong and fragile. It should always be handled with the greatest care and concern.

The body has a finite capacity to process information. With every person the range of that ability varies. Within that range is further variation. For many people there is a real and true desire to achieve experiences just on the edge of that threshold. We tend to call this edge play. In most cases Edge Play is a combination of sensory or physical stimulation coupled to mental and sometimes even spiritual stimulation. It is fairly easy to see the progress or path of physical stimulation techniques, it is much more difficult to evaluate or take a person mentally into differing space.

With an establishment of trust between a Dominant and a submissive the submissive will generally begin to lower their mental walls or shields and allow their Dominant greater and greater access into their private realms. Trust is coupled to the ability to process information. The stronger the trust, the further the submissive will allow themselves to go.

Achieving space for a new submissive is generally accidental. There is a desire and a willingness to try and at some point that first barrier or mental threshold will be crossed and the submissive will find themselves 'in' space. Often this is a frightening and exciting experience. A Dominant should not press that first experience of space but allow it to be full of pleasure and positive chemistries. This will encourage the submissive to actively 'go to that place' in their minds during a scene. To deepen their level of space the Dominant needs to proceed slowly and cautiously. It is essential to remember that trust is the key, if the Dominant says one thing and does another they are providing an unstable surface and the submissive will not trust them as deeply. This will tend to prevent the submissive from releasing their vulnerability further. From a Dominant's standpoint the deeper you can take your submissive, the higher they can fly and the more stimulation they can sustain. Again it is important to note that there are sincere limits here.

Submissive's vary from day to day and moment to moment. On Monday they can space and be at maximum from having nipple clamps while on Tuesday they may need or want zipper's, full CBT or waxing to achieve the same euphoric state. It becomes essential for the Dominant to become so attuned to their submissive's current state that they know where there submissive is at on any given day. There is no right or wrong here. It is merely that the brain may be full with other tasks on some days and only have the ability to 'allocate' a certain amount of space or energy toward processing. With some submissives they will need and require more during times of stress (it almost appears that they become desensitized to lower levels of stimulation or need to overcome the 'stress' by higher levels) with other submissives their ability to process new stimulation during a period of stress is greatly reduced and in fact they may be unable to play during those times. Again, there is no right or wrong, simply variations. Learning such intimacies between partners is crucial. Making an error can propel a submissive into a horrendous event or a scene that they 'feel' later to have been in violation to their needs, wants and desires. This leaves the Dominant in a somewhat precarious position if they only play with that submissive occasionally. They simply cannot know what is going on.

For deeper or edge play I sincerely recommend that the people involved spend a great deal of time together learning each other prior to attempting to play along the threshold. This is not an area where you want to make any mistakes in evaluation or judgment.

The deeper a submissive goes into subspace the worse their communication skills become (verbal). The Dominant should assume that not only can their submissive not evaluate what is dangerous to them, but that the chemistries flowing in their blood stream will essentially mask out their body signals which would normally tell them there are problems. When a submissive is in subspace all of the responsibility for that submissive's safety and welfare rest squarely on the Dominant.

A submissive in deep space can endure broken bones, severe lacerations and many other forms of severe damage without knowing it. Since this type of damage is not what BDSM is about it becomes very important for a Dominant to know not only their submissive's skin, tissue, bone and muscular responses to various implements or toys, but also the full potentials of each implement or toy. Many submissives in deep space will appear or tend to encourage a Dominant into extending the play beyond the limits that a toy or implement has been used on them in the past. Essentially the submissive is to some degree 'high', the sensations increase their feelings of being high and the submissive enjoys that continuation. However, this is also how serious damage occurs. Once the chemistries retreat from the bloodstream and brain the submissive will feel everything. The aftermath can be absolutely horrendous in part because the Dominant will not have known the damage they have delivered until sometimes several days after the scene.

When a couple have played together a fairly long time they tend to relax into an understanding of each other. At this point many submissives will be able to enter subspace quite easily and venture along the energy stream of their Dominant with deep trust. (The Dominant is the net or the safety string that returns the submissive to 'normal space'.) Often both the Dominant and submissive will jointly decide to try something new or go somewhat further. This extension of previous limits can be made slightly more safe if the Dominant trains the submissive to 'bob and top', this is an exercise where the submissive can 'top on command' this means to achieve 'top or normal space' for a moment. Many submissives 'bob and top' to check bindings or pain levels. This may appear to contradict what I said earlier, it doesn't. It is something that only 'some' submissives can do well while others can never achieve it cleanly. Most submissives can learn to do it and should to assist their Dominant in evaluating where they are. Essentially the submissive can top and say something like "right wrist". That is generally about the extent of their ability to articulate speech. They will usually revert back to their prior space almost instantly. The Dominant is left with the cryptic comment which may mean that there is a sincere problem with the right wrist. This tool can be used to aid the Dominant but should not be trusted to the point of removal of any primary responsibility. This tool is particularly helpful if the Dominant and submissive are experimenting with intense bondage or suspension.

Safety in edge play is tenuous at best. The very best safety is simply the deeper the understanding which can only be achieved by long term, frequent interaction. People that play 'on the fly' or casually essentially cannot know their casual partner. The risks of doing damage increase dramatically. To some degree people who desire heavy scening or edge play with basically unknown strangers are demonstrating potential mental problems. BDSM is not about a desire to be damaged. A sincere desire to be damaged or injured reflects a mental problem which reflects impaired judgment which by definition challenges the individuals ability to make sound, reasoned, safe, sane and consensual choices. Written by F.R.R. Mallory – also known as Mistress Steel. This article may be excerpted from  Extreme Space, The Domination and Submission Handbook Safe, Sane and Consensual, Dangerous Choices or other books by F.R.R. Mallory and shared here with her permission. Please click on the book title for information on how you can order a copy of these books and others by F.R.R. Mallory.