|"One of them hit me with a bunch of quick jabs and suddenly I couldn't earthbend anymore and I could barely move."|
|— A member of the Terra Team who was victim to Ty Lee's chi blocking.|
Chi blocking is an ancient technique that has been practiced in secret for centuries. Blocking someone's chi renders the victim's muscles useless and temporarily disables a bender's abilities. It is mainly used by nonbenders as a way of self-defense or even to attack. This ability was notably used in combat by Ty Lee, the Kyoshi Warriors, Thod and his disciples, the Equalists, and Tokuga.
The first time the members of Team Avatar experienced chi blocking was upon the group's initial encounter with Mai, Ty Lee, and Azula in Omashu. The three girls attacked Aang, Sokka, and Katara, after breaking a deal to trade King Bumi for Tom-Tom. During the fight, Ty Lee blocked Katara's chi, rendering her bending useless. However, Sokka arrived and used his boomerang to free his sister, allowing them to escape.
During their second encounter, Mai and Ty Lee chased down Katara and Sokka on the shores of the Nan Shan River. Despite being aware of Ty Lee's skill, she still managed to chi block Sokka, rendering most of his limbs useless. However, she hurt her hand when she attempted to chi block his head.
Ty Lee's chi block ability was of use again when Azula's team led an attack on Ba Sing Se with a drill. Ba Sing Se's Terra Team attempted to stop the machine, but Mai and Ty Lee took them down with ease; Ty Lee dealt paralyzing chi blocking blows to anyone who attempted to fight her.
Later, the trio tracked down Appa once more and discovered that the Kyoshi Warriors were with them. A battle ensued, during which Ty Lee utilized chi blocking to immobilize her opponents. The technique was used yet again after the trio invaded Ba Sing Se disguised as Kyoshi Warriors. Katara came to them after seeing Zuko searching for aid, but once again, Ty Lee paralyzed her, catching her by surprise. Ty Lee also immobilized Sokka and Toph when Azula threatened Earth King Kuei with her firebending, forcing them to surrender.
Ty Lee later journeyed to the Boiling Rock prison with Azula and Mai during Sokka, Zuko, Hakoda, and Suki's escape. The trio pursued them onto a gondola, where Ty Lee faced off against Suki, who was anxious for revenge after being defeated by Ty Lee before. Although Ty Lee attempted to chi block Suki again, the Kyoshi Warrior was able to avoid the attacks, having learned from past experience. Later, when Mai and Azula prepared to fight after the former betrayed Azula by saving Zuko, Ty Lee used chi blocking to paralyze Azula and temporarily block her bending to protect Mai from harm.
While in prison, Ty Lee taught several Kyoshi Warriors the art of chi blocking and joined their group shortly after the end of the Hundred Year War. These lessons allowed Suki to chi block San during an altercation in Seashell San's House of Shells, effectively rendering his firebending ineffective.
The technique slowly became more widespread after the Hundred Year War. In the Southern Water Tribe, Thod had become a master chi blocker by 102 AG and took on two students. They utilized their skill during a conflict with Head Chieftain Hakoda.
During the conflict with Liling and her bender supremacists in Cranefish Town, Suki effectively protected herself with her chi blocking abilities and later passed on the skill to the Earthen Fire Refinery's nonbender guards, forming the basis of an impressive police force that was to be strengthened with trustworthy benders.
By 170 AG, several members of the Equalists movement utilized chi blocking to combat benders during the Anti-bending Revolution. Amon, the leader of the organization and head of the movement, also frequently used the art of chi blocking.
While abducting members of the Triple Threat Triad and Bolin, the Equalist organization was trailed and attacked by an angry Mako and Korra. In response, several of the chi blockers turned to fight them, disabling their bending, an action which frustrated and stunned Korra.
Amon brought a unit of chi blockers with him to a midnight duel with Korra on Aang Memorial Island. As the Avatar was walking away from the island, believing Amon was a no-show, she was ambushed by the nonbenders and chi blocked, rendering her helpless when Amon faced her.
Chi blocking relies on rapidly hitting pressure points with quick jabs and punches, often giving little time for the recipient to react. Ty Lee hit those pressure points with relatively light jabs using her fingers and knuckles, though any fingers can be used, such as when Ty Lee disabled Katara with her thumb. Ty Lee could also use her feet to disable others' chi flow; she used this method to fend off the boys who cornered her in Chan's house.
A more temporary form of chi blocking can be used against combustionbenders, such as Combustion Man and P'Li. Since combustionbending requires a properly calibrated focus of chi channeled through the forehead, often marked by an intricate third-eye tattoo, the technique can be temporarily disabled by striking this marking to disrupt the flow of chi, causing the combustionbeam to misfire until proper flow is restored.
Chi blocking stops a bender's chi flow, reduces their muscular strength, and disables their bending abilities temporarily; this would be particularly devastating for people who rely solely on their bending to fight. A master chi blocker is able to control the damage done by the technique: when Ty Lee first attacked Katara with the art, the latter was still able to move though not bend, but when Ty Lee assaulted the Terra Team, they could barely move, were powerless, and felt pain afterward. Katara later attempted to heal the fallen men but noted that they had been completely cut off from their chi, placing them beyond her help.
Azula described the chi blocking sensation as a feeling of all the joints going soft, "like they're made of melted wax", and one felt "more flexible than you ever thought possible" the moment the chi blocking effect wore off completely.
Anticipation: Although a useful method of fighting, chi blocking is most effective against an opponent not expecting such a light blow to be so devastating. When confronted with someone knowledgeable about chi blocking, they can anticipate the attack and adapt their fighting style to avoid being struck, as demonstrated by Suki when she faced off a second time against Ty Lee atop the gondola. When a bender knows they are fighting a chi blocker, they can use their bending to keep the chi blocker at bay with long-range attacks, preventing them from executing their technique.
Metal armor: Since chi blocking relies on the ability of hitting pressure points, a strong armor is capable of deflecting the crippling blows. To this end, Sokka designed chain mail armor to deceive Thod and his students, and the Republic City Police Department donned segmented metal armor as their standard uniform to withstand the attacks from chi blocking Equalists.
- Chi blocking resembles the martial arts technique, Dim Mak, which purports to kill or maim by disrupting the body's flow of internal energy. It also has some connections to varma kalai, an ancient martial art of Southern India.
- Qigong ( ) (sometimes spelled Chi Gung), a form of traditional Oriental medicine, uses similar techniques and pressure points to help others' chi flow more easily and is considered a standard medical technique in Chinese hospitals.