Sword

At its core, every sword brings together three parts: a metal blade ground to at least one cutting edge, a shorter grip meant for one or two hands, and a guard that seats the blade and shields the wielder's fingers. Many of the world's renowned examples borrow the uchigatana form, pairing a wide guard and curving single edge with a tempering pattern called hamon, which appears either as a clean straight line or as a wavy irregular one. The weapon excels at melee through cutting, thrusting, and parrying, though its reliance on a wielder's skill and its limited reach count as real shortcomings.

According to the smith Shimotsuki Kouzaburou, blades carry their own temperaments, and the more willful ones can overwhelm a weak owner, even to the point of death, which is how a sword earns a reputation as cursed. A swordsman who lacks raw strength must learn a blade's character and bend it to his will, while a powerful master such as Kouzuki Oden could swing the draining Enma as if it weighed nothing. Quality sets a sword's price, ranging from a cheap fifty thousand Belly blade to a hundred thousand for a fine one in Loguetown. The most distinguished weapons fall into three groups: Famous Blades earned through master forging or famous owners, the four ranked tiers of Grade Blades prized for cutting power, the rare Black Blades darkened through countless battles using Armament Haki, and the dreaded Cursed Blades.

The series showcases an enormous spread of forms tailored to each fighter. Katana and sabers appear most often, with Roronoa Zoro carrying several katana and high Marine officers favoring them too. Other shapes fill out the roster: training shinai of bamboo, knife-like kogatana and kogatana, short wakizashi and tanto, the long-reaching nodachi wielded by Trafalgar Law, broad Chinese dao and nandao, double-edged jian, naval cutlasses and sabers, curved kukri, cane-hidden shikomizue used by Brook and Issho, plain shirasaya, oversized zanbato such as Arlong's Kiribachi, slender rapiers, straight longswords like Mihawk's Yoru, whip-like urumi, machetes, and curved shotels. Master smiths of Wano Country, including Kotetsu and Kouzaburou, forge the legendary Famous Blades that outclass ordinary steel.