Edge play is dangerous; do not try this at home!
Knife play is generally a form of fear play, sensation play and light medical play if it involves making scratches and abrasions, though generally speaking knifeplay does not involve branding, cutting or other fusion techniques unless it is explicitly discussed as part of negotiations.
Knifeplay often involves moving a blade across sensitive portions of the skin, threatening safety with a knife, and minor scratches and abrasions that might result from light pressing the blade to the skin, if the blade is not cleaned this may lead to infections. Some minor scratches may stay for weeks or months on easily marked skin while others will heal in a few days. Additional risks from improper technique may include being cut or impaled resulting in minor, serious, or deadly wounds, or having unknown psychological fears being triggered, resulting in an unpleasant experience or full psychotic breakdown. If blood is let, cross contamination of the blood may occur which may result in contraction of STI or other bloodborne pathogens.
- Discuss if knives are a psychological trigger, or if touching a specific area with a knife is a psychological trigger, or if menacing with a knife is a psychological trigger and if clothing can or cannot be destroyed.
- Discuss if either possesses any Bloodborne Pathogens or STIs to prevent cross contamination. Utilize a barrier (such as rubber gloves) if bloodletting is expected to occur.
- Discuss if the scene is intended to incorporate advanced fusion techniques such as bondage, cold and heat, fire, electricity, cutting, branding, scarification and similar.
- Equipment is cleaned, sanitized and laid out in a safe manner so that it won't accidentally cut or impale someone during an accidental fall. Be sure to play used knives out of traffic areas and to clean and sanitize them thoroughly before storing them.
- The concept and title of edge play is derived specifically from the idea that knives are sharp and very dangerous; respect the power and danger of the blade. Be sure you have practiced your control to a point where you are comfortable placing a knife on and running it along your own sensitive bits long before you ever place a knife on the skin of another. Actual knife play is even more dangerous than this because your partner may move, jump or sneeze unexpectedly and you are required to react without notice for their safety.
- If this is the first time the bottom has experienced knife play, test their reactions with the blindfold and bondage technique before utilizing a sharp edge on their skin.
- During aftercare be sure to disinfect any scratches and dress any cuts on the bottom using first aid techniques to prevent infection and aid in healing.
- Do not close or sheath knives during a scene once they are used, disinfect them first. Be sure to store them out of the way so they do not become a hazard during continued play.
After you have completed negotiations consider experimenting with some techniques after having practicing them on your own.
- Show the blade Show them the knife so that they are aware of what is about to be done to them as this can enhance fear play. If you plan on showing it to them close to their head or eyes, ensure they are securely bound so as not to jump or move unexpectedly to cause injury to the face, eyes, head, or neck. Be sure to understand the safety of knife play, fear play and bondage before attempting this fusion technique.
- Threatening Whisper knife play is mostly about fear play. Get inside the head of the bottom by utilizing threatening words, language and movements (albeit highly controlled movements). Help them experience the fear by giving them a fantasy environment in which they can reasonably feel fear. Avoid being predictable.
- Clothing Removal pull clothing away from the body and cut away from the bottom to remove clothing. For thick materials cut off buttons and fasteners rather than through the material. Always negotiate clothing removal and destruction before it occurs. Be especially mindful if you intend to cut a skirt vertically or any time that you might be cutting towards the bottom.
- Two Handed use two knives on your partner by picking up a second blade. Be sure you can keep an eye on both and watch the subtle body language of your partner to tell if they are about to move unexpectedly. This gives you additional range to place sensations at opposite ends of the body or to run both knives parallel, one behind the other or some other variety that makes your knife play less predictable.
- Blunt Impact utilize the handle of the blade for light, blunt impact. Be sure to be aware of all knife and impact safety before attempting such fusion techniques. Similarly, some blades can use the flat of the blade for a slapping impact, though depending on the blade edge and how the blade is used this can have a potential to cut open the bottom.
- Butterfly Flourish the butterfly flourish is a technique utilizing a butterfly knife in which the knife is brandished and flipped open in a flashy and potentially intimidating manner if coupled with a predatory grin and piercing gaze. This technique can enhance fear play. 
- Blindfold and bondage This is a bait and switch technique done for safety. Place your partner in secure bondage that helps prevent them from wiggling much such as being firmly wrapped in several places to a table, pole or back board. Show them the knife so that they are aware of what is about to be done to them and then place a blindfold on the partner.
Without the partner's awareness change the sharp blade for either the dull side of a blade, a chilled metal dull blade or an electrified metal dull blade.
Utilize the new tool and run it across the skin of the bottom utilizing any psychological word play you may have prepared, often a well placed "Don't Move" whispered in the ear is effective. This will test the reaction to the "knife" to see if they jump or squirm in fear while thinking they are in danger. In the case that they do jump or squirm they will not be sliced open and will be relatively safe because of the use of the dull implement. At worst in most cases they might have a dull pain from a poke of the tip of the object, which is far better than a trip to the emergency room.
When you are comfortable you may change out the tool for the knife blade to operate on your partner. You may or may not decide to show them that you faked them out with the dull tool depending on what you'd like to achieve. Be sure to understand the safety of knife play, fear play and bondage before attempting this fusion technique.
- One sided blade As part of the blindfold and bondage technique, simply flip a one sided knife over to the dull side and drag this along the skin of the bottom. It will feel similar to a blade edge but not be as sharp. This technique has the advantage of being able to be easily switched back and forth between sharp and dull.
- Chilled metal This techniqe requires freezing the blade in advance and may include the use of a glove to ensure you don't freezer burn your hand. The effect can be done to any metal object to make the edge feel sharper, meaning you can make a butterknife or letter opener feel as if it is as sharp as a blade. Further, if once the blade starts to warm after a short period, you can quietly dip it into an ice bucket to regain some chill and then run it across the skin again, pressing slightly harder. This will make the tiny water droplets running down the skin potentially feel like blood running from a cut without ever having to break the skin. See also mindfuck.
- Electrified Metal Like the chilled metal technique, electrifying a dull object like a butterfly knife or letter opener with violet wand techniques will make the dull metal feel much sharper, almost like it is flaying their skin, depending on the setting. Be sure to understand all knife and electro safety before attempting this fusion technique.
For additional stimulation, you may wish to use plastic wrap bondage on the body of the bottom and remove it with a knife while the bottom is electrified which can create a strange sensation to the bottom that has been described as being slowly flayed.
- Throat Cut the very idea of a knife dragging across the throat is enough to spook many and this may be a psychological trigger, make sure to use a dull instrument (one sided blade technique) the first time you attempt this with a partner to ensure safety.
- Electrified Blade if electricity makes a blade feel sharper, using a real knife or machete edge in conjunction with a violent wand can be a very intense experience. Be sure to understand all knife and electro safety before attempting this fusion technique.
- Heated Blade heating a blade in a candle fire or similar can cause a hot blade for additional sensation play, use a cheap knife you don't mind replacing for this technique that doesn't have a coating on it that will melt off. Be sure to test the knife on your own skin before applying to a bottom, much like testing the heat of a baby bottle before giving it to a baby to ensure they aren't injured. Blades that are overheated can permanently brand, especially on sensitive skin. Be sure to understand all knife and fire safety before attempting this fusion technique.
- Pyro Blade Utilizing dripping wands techniques one can light the blade itself on fire for a brief moment by dripping lit alcohol onto the knife edges. Heating a blade with fire can cause a hot blade for additional sensation play, use a cheap knife you don't mind replacing for this technique that doesn't have a coating on it that will melt off. Be sure to test the knife on your own skin before applying to a bottom, much like testing the heat of a baby bottle before giving it to a baby to ensure they aren't injured. Blades that are overheated can permanently brand, especially on sensitive skin. Be sure to understand all knife and fire safety before attempting this fusion technique. This technique is best done without a blidfold so the bottom can see the impressive stunt.
- Scarring Inform the top during negotiations if your skin scars easily and whether or not you enjoy marks so they can adjust their technique during the scene. Semi-permanent marks from knife play are common on those that might easily mark from a scratch.
- Feel and Imagine Unless you are incorporating various dangerous elements like cutting, branding, fire or electricity, knife play is mostly psychological and fear based. Attempt to capitalize on the intention of the scene by imagining and fantasizing a scenario in which you are truly afraid of the knife.
- Be Open Alternately, knife play scenes can be entirely about building trust, if that is the case, be sure to embrace that aspect as well by being open to the concept of trusting your partner during the scene.
- Replaceable Clothing If you are planning to be in a knife play scene and you would like your clothing to be forcibly removed, purchase some clothes from good will or wear some old clothes you don't care much about as this will save money on purchasing expensive clothes if that is a concern, and prevent your favorite clothing from being destroyed. Choose clothes that are thin materials or have buttons to assist in the ease of tearing them off with the knife or hands. Choose clothing pieces that are likely to inspire your top to enjoy tearing them off. Avoid clothing (especially underwear) with very thick and tough elastic bands as these can prove difficult and dangerous to remove with a knife.