Dual dao swords, also known as twin broadswords, are weapons used by Zuko during his banishment which are forged with metal; they are known to be used in the Earth Kingdom and the Fire Nation. The swords can also be used individually as single-edged blades.
These swords were on display in Prince Zuko's ship quarters and were first used when he assumed the identity of the Blue Spirit. He used the weapons to defend Avatar Aang and rescue him from Pohuai Stronghold, a Fire Nation fortress in the western Earth Kingdom. He also threatened Aang's life with them in order to trick Zhao into allowing them to escape. Zuko utilized the dual dao swords to conceal his firebending.
When Zuko and Iroh were traveling through the Earth Kingdom as refugees, they had a hard time collecting sufficient money to get by. While stopping in the river village, a passerby used his dual dao swords to make Iroh dance for a gold piece, much to Zuko's annoyance. The angry prince later mugged the swordsman under the guise of the Blue Spirit and stole the man's swords. He used these swords to steal from local Earth Kingdom villagers along his journey.
In the plains village, Zuko used his swords to fight Gow and his gang, and later used them in combination with his firebending after Gow nearly defeated him. He also taught Lee some techniques with these weapons, calling them, "two halves of a single weapon" and telling him not to think of them as separate.
In Ba Sing Se, Zuko used the swords against Jet during their duel in the tea shop. He had to use them in order to hide in the Earth Kingdom as a refugee, concealing his firebending. Zuko then returned under the Blue Spirit guise and utilized his swords when he liberated Appa.
During the Day of Black Sun, when Zuko confronted his father, Fire Lord Ozai, he wielded his swords as a method of defense, since at that time he could not use firebending due to the solar eclipse.
Dao swords are moderately curved and single-edged, though often with a few inches of the leading back edge sharpened as well; the moderate curve allows them to be reasonably effective in the thrust. Hilts are canted, curving in the opposite direction as the blade, which improves handling in some forms of cuts and thrusts. Cord is usually wrapped over the wood of the handle. Hilts may also be pierced like those of the jian, a straight-bladed sword, for the addition of lanyards. The dual dao swords used by Zuko had specially shaped guards that allowed both blades to be sheathed in a single scabbard.
The earliest dao date from the Shang Dynasty in China's Bronze Age, and are known as zhibei dao () - straight backed knives. As the name implies, these were straight-bladed or slightly curved weapons with a single edge. Originally bronze, these would be made of iron or steel by the time of the late Warring States. Originally less common as a military weapon than the jian - the straight, double-edged blade of China - the dao became popular with cavalry during the Han dynasty due to its sturdiness and superiority as a chopping weapon. Soon after dao began to be issued to infantry, beginning the replacement of the jian as a standard-issue weapon.
- The Avatar Extras bonus commentary of "Zuko Alone" stated that Zuko's dual swords are meant to represent the conflicting "good" and "bad" sides of him and that both are different parts of himself.
- This weapon is one of the four major Chinese weapons, known as "The General of All Weapons". Unlike Sokka's space sword, Zuko's swords are like traditional dao swords: single handed and single-edged.
- In the comic "Swordbending", it was revealed that Piandao instructed Zuko in the art of the dual dao swords.