San Jian Liang Ren Dao (三尖兩刃刀)

San Jian Liang Ren Dao of the Ming period, private collection.

The San Jian Liang Ren Dao (三尖兩刃刀, lit. 'Three-pointed double-edged blade'), also known as Er Lang Dao (二郎刀, lit. 'Erlang's blade') due to its association with Chinese war deity Er Lang Shen (二郎神), was a versatile but underrepresented Chinese polearm.

Like its namesake, the San Jian Liang Ren Dao had three points and two long, slightly flared cutting edges. The three points allowed the weapon to parry or even bind an opponent's weapon effectively while retaining the ability to deliver powerful stabs, whereas its forward-weighted cutting edges rendered it a devastating chopping weapon.

Being symmetrical, the San Jian Liang Ren Dao was also better balanced than other multipurpose polearms, such as the halberd.