In Avatar: The Last Airbender, Earthbending is the art of reshaping everything made of mud, sand, soil, rock and other assorted earth-based substances. It is as old, and as important, as any of the other three elemental styles (although the narrative tends to focus more on Earth Kingdom culture and traditions than the bending art itself.)
Interestingly, while the Earth King of Ba Sing Se may not have been an Earthbender, his city was an impregnable refuge for those escaping the Fire Nation for the longest time. What are some of the little known facts about this genre of bending?
10 Specialized Forms Of Earthbending
The most famous example is Metalbending, which is conjured by Toph Beifong while literally being carted back home to her family. Then there is something known as "dust-stepping," in which practitioners can produce extremely narrow columns with gradually increasing heights (in order to climb over walls, for instance.)
Glassbending is also claimed to fall under this category, but the only evidence for this comes from Avatar Kyoshi's use of the technique. Similar to this, Aang employs crystals to wrap an armor around himself while fighting Azula, although it's clearly not meant to withstand lightning. Earthbending also includes Lavabending and Sandbending, as described below.
9 The Complicated Art Of Lavabending
As tricky as it may seem, all Lavabending needs is a practitioner in sync with their own innate energy — as proven when Bolin manages to defeat Ghazan despite having zero practice.
In the canon, the first time this method is depicted is when Szeto, four Avatars before Aang, triggers a multi-volcanic eruption; and Kyoshi also used it to separate the Earth kingdom from Chin the Conqueror's vile destruction. However, most Lavabending come from Ghazan's activities, at least until Bolin accidentally-on-purpose figures out how to do it himself.
8 Earthbending Has Dangerous Weaknesses
Unlike Firebending, Airbending, & Waterbending, in which the elements can be manipulated regardless of location, Earthbending is confined to... well... the Earth. This obviously poses a huge problem, as attacks that come from above are rarely noticed by even the sharpest Earthbenders.
In fact, even Toph fails to react in time when Sokka accidentally "drops" a belt on her head, even though she could sense Combustion Man from half a mile away through Earthbending.
7 The Creation Of Omashu
The ruler of Omashu ends up being Aang's childhood pal, Bumi, a master Earthbender in his own right (who is given tribute in the form of Aang's firstborn son.) The story, however, occurs far before this — the lore describes a couple of lovers, Oma and Shu, who enter a Romeo & Juliet-esque romantic tryst in the midst of war between their own villages.
They apparently picked up Earthbending by watching the Badgermoles, and created an enormous underground maze that only they knew the secret to (the clue is: "love is brightest in the dark.") Shu is murdered in battle, and Oma almost murders everyone in her fury, but instead forces the combatants to lay down arms and live together in a new city, later renamed Omashu.
6 The Effect Of Geological Fault Lines
Like the Sun's influence on Firebending and the Moon's on Waterbending, Earthbending derives its power from the geological fault lines that span the Earth. Deep within the planetary crust, tectonic plates move across each other, producing "fractures" known as fault lines.
It is interesting to note that the rapid movement of specific fault lines is the main reason behind earthquakes, as this generates extremely massive quantities of energy. Further, Earthbenders are known to cause earthquakes, but their magnitudes are as yet unclear.
5 The Unique Culture Of Sandbenders
The Si Wong desert might look like a desolate wasteland, but it is populated by a native tribe of Earthbenders known as Sandbenders. They are able to control sand, something very few Earthbenders find it easy to do, as Toph learns to her annoyance while stuck between saving Team Avatar or Appa.
These Sandbenders transport themselves on large desert boats known as sand-sailers, and often resort to thievery and kidnapping in order to make ends meet. Unfortunately for them, they abduct the closest friend of the Avatar, and barely manage to survive his glow-eyed wrath.
4 Directional Geomancy
One of the tests Aang was given in order to ascertain his status as the Avatar was to make a choice between a fixed number of toys (only the real incarnation would choose the same ones that had once been owned by other Avatars.) On the other hand, when it came time for an Earthbending Avatar such as Kyoshi to be born, the rules were far more complicated.
This method, known as directional geomancy, employs a unique array of "bone trigrams" that are cast and based on their positions, allegedly informing the casters as to the approximate neighborhood of the latest Avatar. However, this process is required to be repeated multiple times before the exact locale can be narrowed down.
3 The Seismic Sense Of Toph Beifong
Being cooped up at home by overprotective, hyper-rich parents, Toph sneaks out to go hang with her new best friends, the Badgermoles. Both of them being blind, they adopt her as one of their own and impart their ancient knowledge to the young girl the most important of which being Seismic Sense.
This technique of "feeling" the vibrations of the land cannot be considered strange or bizarre, even though most Earthbenders are clueless about it, because it is at the core of all Earthbending. The Seismic Sense allows Toph, and later Aang & everyone else, to perceive the world through Earthbending, which means it is almost impossible to defeat her in a fight (on the ground.)
2 The Necessity Of Self-Control
When Toph teaches Aang her craft, she stresses on making a connection with the Earth itself, rather than vaguely flailing his arms around hoping for the best.
Earthbending, as King Bumi explains, depends on the maintenance of neutral jing — the act of doing nothing is crucial depending on the circumstances, as one might find it more advantageous to patiently wait for the exact moment to make a decision arrives. He uses the coincidental timing of the solar eclipse to escape his coffin-shaped metal prison.
1 Earthbending And The Shaolin Martial Art Of Hung Ga
Earthbenders might not be as dynamic as the other forms, being the only one that deals with (mostly) solid material, but its practitioners can be supremely adept, an example being the Dai Li of Ba Sing Se.
Earthbending is partially based on the famous Hung Gar martial art in that the latter depends on extremely firm (almost immovable) posture, as well as powerful attacks that are meant to mirror the overwhelming weight of the Earth. Toph, however, uses a slightly different mode of fighting, influenced by the Southern Praying Mantis style.