Nen is a technique that allows a living being to use and manipulate their own life energy (known as aura). The term "Nen" can also be used in conversation to refer to aura. A person capable of utilizing Nen is colloquially referred to as a "Nen user" (, nōryokusha—lit. "ability person"), while those who cannot go by the name of "non-users" Because one can craft a great variety of para-psychological abilities through Nen, it is considered a dangerous power that is kept hidden from the public at large to maintain balance in society.

is an advanced application of Ten and Ren. In Ren, aura usually envelops only a small amount of space around the user's body. En is when one extends their Ren so that their aura extends further than normal, then uses Ten at the same time to contain and give shape to that aura, normally a sphere. The minimum requirement is to extend one's aura to a radius of more than 2 meters (6.56168 feet) and hold it longer than 1 minute. Someone using En can feel the shape and movement of anything within the area covered by their aura, with the degree of awareness and finesse depending on their level of skill. Nen users can be told apart from regular people due to their stronger reaction to the En user's aura.

Those who master En are typically able to extend it to a circle with a 50 meter (54 yard, 2 foot, 0.5052 inch) radius. There are exceptions, however: Zeno Zoldyck, one of the most powerful assassins alive, is able to extend his En up to a radius of 300 meters (328.084 yards), while the Chimera Ant Neferpitou has an irregularly shaped En and can extend a tendril up to 2 kilometers (1 mile, 427 yards, and 8.0064 inches). The downside to this technique is that it is extremely tiring and draining for the Nen user to constantly deploy so much aura.

Once a person has opened their Aura Nodes, they must learn to keep their aura from leaking away from their body. Once a person has opened their Aura Nodes, they must learn to keep their aura from leaking away from their body. Ten is the process of keeping the nodes open, but also having aura flow through and around the body rather than away from it. Once maintained, it creates a shroud around the user that feels similar to standing in a lukewarm, viscous fluid. Ten maintains youthful vigor and reduces one's aging, since the energy powering the body no longer leaks away; one can keep the body from breaking down and deter the aging process.Ten is the most basic defense against emotional Nen attacks,  andit also offers limited protection against physical attacks, but hardly any when said attacks are enhanced with aura. Through frequent meditation and practice, one can improve the quality of their Ten and even maintain it in their sleep. Once it has been learned, it will never be forgotten, much like cycling and swimming.  Despite being the most elementary technique of all, Ten is also one of the most important, since, together with Ren, it plays an instrumental role in determining the strength and smoothness of a Nen user's aura flow Ten maintains youthful vigor and reduces one's aging, since the energy powering the body no longer leaks away; one can keep the body from breaking down and deter the aging process.Ten is the most basic defense against emotional Nen attacks,  andit also offers limited protection against physical attacks, but hardly any when said attacks are enhanced with aura. Through frequent meditation and practice, one can improve the quality of their Ten and even maintain it in their sleep. Once it has been learned, it will never be forgotten, much like cycling and swimming.  Despite being the most elementary technique of all, Ten is also one of the most important, since, together with Ren, it plays an instrumental role in determining the strength and smoothness of a Nen user's aura flow

 is an advanced application of Ren by which a Nen user concentrates a larger than normal portion of their aura into one specific body part. It increases the strength of that one body part, but leaves the rest of the body more vulnerable. Gyo is most often used in the eyes, allowing a Nen user to see aura and Nen constructs concealed with In as well as traces of aura that so faint that they might go unnoticed otherwise.

An alternative version of this technique gathers only the aura naturally leaking from the body instead of the greater amount produced with Ren. This application of Gyo can still increase the amount of aura in one select body part and thus its power, but the output is much lower than what is obtained through the regular technique. It is unlikely this lower-consumption Gyo could counter In, since Wing had all his students perform Ren to do so. However, it has proven to suffice to see thin layers of aura as well as to perform Water Divination correctly.

is an advanced form of Zetsu used to render one's aura imperceptible, effectively concealing it. Unlike Zetsu, however, In does not stop the user's aura flow; instead, it hides it, making it impossible to perceive with any of the five senses or extrasensorial perception. Hence, this technique is perfect for launching sneak attacks or laying traps, as it can conceal not only the user's presence, but also Nen constructs generated with Transmutation, or Conjuration.

In can be countered by using Gyo in the eyes or through Zetsu. When Inconceals part (or even all) of the user's aura output, experienced Nen users can divine their opponent is using it if little or no aura can be felt from them in circumstances which would normally require it, such as during combat.

Shu allows a user of Nen to enshroud an object with their aura, allowing them to use that object as an extension of their own body. For example, one could use Shu to extend their Ten around a weapon, which would strengthen and protect it. Shu can be combined with other techniques, such as Ko.

 is a combination of Ten, Zetsu, Hatsu, Ren, and Gyoin which all of the user's aura is concentrated into one particular body part. Gyo is utilized to focus aura on a part of the body, while Ten is used to prevent it from dispersing. Zetsu is used to completely stop the flow of Nen in all other parts of the body, increasing the output in the desired area. With Ren, the amount of aura is increased even further. This makes that one body part extremely powerful, but at the cost of leaving the rest of the user's body completely unprotected. Due to the risk it carries, Ko is regarded as a purely offensive technique. An incomplete version of this technique can be utilized without Ren, primarily to master the other steps before increasing the amount of aura to concentrate and contain. Some Nen users, Enhancers in particular, employ Ko as a Nen ability by adding conditions to 

 is the advanced version of the basic Ren and Tentechniques. It is a primarily defensive technique where a Nen user maintains a state of Ren for a prolonged amount of time. The amount of aura surrounding the user's body during Ken is about 10 times higher than during Ten. Ken allows a Nen user to guard against attacks from any direction, but the large amount of aura produced makes it tiring to maintain. It is considered the best option to defend from Ko, despite not being as powerful as the latter on any given part of the body, as it protects all of it evenly. When not immediately at risk of being struck with Ko, Ken is utilized when one wants to be cautious. Some Nen users choose to expand its radius so as to sense incoming attacks they are unable to see, as a miniature En of sorts. Sometimes Ken is colloquially called Ren owing to the similarities between the two techniques.

 is the term for use of Gyo from a state of Ken to perform real-time offensive and defensive value adjustments. If Kodevolves 100% of one's aura to offense or, much more rarely, to defense, and Ken splits it evenly between the two, Ryu is redistributing one's aura according to any other percentage, for example by focusing 70% of one's aura in one fist as one is about to strike, or 80% in one's leg to block an incoming kick. It is utilized to damage a Ken user without leaving oneself as unprotected as during Ko, although the power of the technique is lower. Ryu is difficult to master, as it requires not only to control one's aura flow with great precision, but also to be able to estimate the amount of aura utilized by the opponent at a glance. Even if the technique is performed correctly, the movements of the aura flow risk giving away the user's next move if they are too slow.

 focuses on outputting a larger amount of aura than Ten, projecting it outwards explosively. This amplifies the user's physical strength and durability and provides a large pool of aura for any advanced techniques or individual skills they decide to use, albeit at the cost of expending said aura. One can train their Ren to extend its duration and increase the amount of aura at their disposal. It is said it takes one month to prolong one's Ren outside of combat by 10 minutes. If Tenis considered purely defensive, Ren can be regarded as its offensive counterpart, although it also grants the user vastly enhanced defensive abilities. With the right timing, Ten can be used to contain the aura produced with Ren.

By tingeing one's Ren with hostility, a Nen user can exert what is colloquially referred to as "bloodlust". A prolonged emission of malicious Ren can induce uncontrollable dread in those who cannot use Nen, paralysis and if contrasted without Ten, even death. On the other hand, a neutral Ren can rarely be felt by non-users. Since Ren is a show of power, it can also intimidate other Nen users, as it offers an approximate measure of the user's raw strength; in fact, by "show me your Ren", Hunters generally mean they want to see the fruits of one's training, such as a Nen ability, rather than their Ren In most cases, Ren reflects the user's hostility without their control, and it can even leave faint traces in the environment after the Nen user has left the scene.

is one's personal expression of Nen. Its qualities are influenced by but not restricted to the Nen user's natural Nen category, one of the six available. Hatsu is used to project one's aura to carry out a certain function, creating a special and unique paranormal ability that is colloquially referred to as a "Nen ability" 

At first, Hatsu appears simply as a consequence of using Ren during Water Divination; however, it is more than a mere property of the latter, and it can be trained individually either through Water Divination itself, which however seems to only affect the user's natural category, or by honing one's skills in a Nen category via specific exercises. Once a certain level of skill has been attained, the student can attempt to create their personal Nen ability. Since they can have an immensely vast range of effects, Nen abilities may be recognized as any manifestation of one's Nen that cannot be ascribed to one of the basic or advanced techniques, although there are instances of Nen abilities being essentially applications of Ko (an advanced Nen technique which makes use of Hatsu) with special conditions or restrictions. A good Nen ability reflects a person's own character, regardless of its complexity; one can never truly master Nen if they only copy someone else's abilities.

in a 65ft radius a creature with Darkvision can see in Darkness as if the Darkness were dim light, so areas of Darkness are only lightly obscured as far as that creature is concerned. 

Chimera ants can see in complete darkness due to their heightened senses and abilities