Polearm

A pole weapon or polearm is a close combat weapon in which the main fighting part of the weapon is placed on the end of a long shaft, typically of wood, thereby extending the user's effective range. Spears, glaives, poleaxes, halberds, and bardiches are all varieties of polearms. The purpose of using pole weapons is either to extend reach or to increase angular momentum—and thus striking power—when the weapon is swung.

Strengths and Weaknesses
Several characters have been seen using polearm based weapons. They offer a much more massive reach than most weapons and serve a variety of uses both offensively and defensively. The advantage they offer is a superior range in close combat to other weapons such as the sword.

However, the main offensive aspect of the weapon is on the furthest end of the pole where usually a blade is held for striking. The main offensive stance of a polearm user is therefore usually focus forward on the bladed end, the idea is to strike down the foe before they come anywhere near the user and it is often difficult to change fighting stances in tight spaces, with the only exceptions being the staff branch of pole arms.

At its core, pole arms combatants are relatively easy to train while the weapon itself is cheap to produce.

In One Piece, polearm users have been seen mostly seen used by guards and few have been seen wielding one in battle. Unlike the sword, most uses have been just for striking or show and very few polearm based techniques have actually been featured since the most common seen wielders were background extras. Both Gol D. Roger and Noland were killed by executioners who wielded polearm based weapons.

Types of Pole Arms
Polearms are separated into different classifications by the type of tip. They vary in design from the basic fighting staves having no tips at all to the more specialized tips of the Halberds. All types of polearms fall into one five specific groups: Staves, Spears, Halberds, Scythes and Mauls.

Staves
Staves have a variety of uses, although most are not weapon based. Only a few types of staves are counted as weapons such as the quarterstaff and long staff. Staves are a form of Stick fighting. Stick Fighting is not a method of pole arm fighting and only fighting staves fall under the pole arm classification.

Bo
The bo (棒) is a long staff weapon.

When she was first seen, Nami used a bo for fighting, this was later replaced with the Clima-Tact, although by classifications the Clima-Tact is still considered a type of bō. The Nonosama Bo, Enel's golden staff, is also a bo, albeit made from gold, and can be reforged into a trident with his Goro Goro no Mi powers. Vergo uses a bamboo stick as a bo staff, imbuing it with Busoshoku Haki to increase its hardness.

Jitte
The jitte (十手) is a short staff with an extra protrusion that is specialized in disarming the opponents.

Smoker carries a Seastone-tipped jitte that is actually much longer than a normal one, and is over 83 inches long based on its name. In the anime, Commodore Kibin was seen wielding a normal jitte.

Spear
The spear (槍) is a basic polearm weapon usually characterized as a staff with a pointed head.

Don Krieg's Mighty Battle Spear is a giant spear with a bomb attached at the base, allowing him cause massive explosions as well as stabbing damage. Members of the Shandia tribe were seen using spears, it was particularly noted to be used by Kamakiri. The guards at Mariejois were also seen holding spears. Noland's crew were prevented from protesting their captains innocence and spears were used to keep them at bay and stop them saving their captain's life. The most notable figure with spears is Ikaros Much who wields a total of 6 spears altogether, one in each arm the spear heads actually being dried squids.

Trident


The trident (トライデント) is a particular branch of spear, usually with three prongs at the end and designed for thrusting.

The trident was first introduced in the series by Enel, who forged it on the tip of his staff using his ability after realizing blunt attacks will not work on Luffy. King Neptune uses a trident, as well as Hody Jones, Prince Fukaboshi, Aladdin, the Ammo Knights and Abdullah. The Minister of the Right owns a unique bladed trident that is based on a trishula. Hatchan also owns a golden trident which was given to him by the Goldfish Princess.

Trishula
The Minister of the Right has a trishula (トリシューラ), although many tridents seen within the series have characteristics borrowed from the Trishula. The middle point on the Trishula is also very distinct; it is always longer then the two side points. Although it is regarded as a type of trident, unlike the trident it is also possible for the Trishula to have more than 3 spear prongs.

Pitchfork
The pitchfork is an agricultural tool that resembles a trident in appearance.

It's a standard weapon for the employees of Impel Down. Chief Guards Saldeath and Sadi wield customized pitchforks, with Saldeath's doubling as a flute for controlling the Blugori and Sadi's doubling as a whip. Hannyabal also owns a pitchfork, however, he seems to favor Kessui, a naginata-like weapon, for combat.

Lance
A lance (ランス) is a type of long spear with a large, conical head.

Shura wielded a lance known as a Heat Javelin, which has a Heat Dial inside. Gan Fall also uses a lance while riding on his pet bird Pierre in his hybrid form. At Thriller Bark, some of the General Zombies were seen using lances as well. Speed Jiru was seen with a lance and a shield. Epoida was seen wielding a double headed lance. The Dwarves of the Tontatta Tribe use miniature lances that are suitable to their diminutive size.

Halberd
The halberd (ハルバード) consists of an axe blade topped with a spike mounted on a long shaft. It always has a hook or thorn on the back side of the axe blade.

Boa Marigold owns a halberd with a particularly oversized blade.

Bisento
A bisento (眉尖刀) is a heavy halberd, and is Whitebeard's signature weapon. The weapon's size is massive, fitting that of its owner, with a striped pole (with the stripes being all plain brown in the anime, but red and yellow in the manga) ending in a spherical edge, and a curved, large blade attached to the pole via a golden part, decorated by what looks like a sea snake, with a thin part of it protruding on the blade itself. After his death, it became his grave marker. Edward Weevil, who claims to be Whitebeard's son, also uses a bisento like the late pirate.

Naginata
A naginata (薙刀) consists of a wooden shaft with a curved blade on the end.

Hannyabal's Kessui is a naginata, but was a double bladed type of naginata, which is not normal for the naginata to have; it is more of two katanas merged together by the endpoints of the hilt.

Guandao
A guandao is usually characterized as a pole with a curved blade at one of its ends and sometimes decorated with a tassel or sash. The other end of the pole usually has a small mace head used for counterbalancing. The main difference between a guandao and a naginata is that the latter tends to have a longer, thinner blade.

Sai of the Happo Navy uses a guandao not only as a weapon for offense and defense, but also as a tool for pole vaulting, which allows him to perform acrobatic Hasshoken moves.

Scythe
A scythe (大鎌) is a wooden shaft (though sometimes metal or plastic) with a long, curved blade projected to the side. Due to its design, the blade only causes cutting damage by swinging, and is not meant to be used for stabbing.

Doc Q uses a scythe with a metal shaft, and double blades, one on opposite side of the other; a weapon worthy of his epithet, "Grim Reaper", who are traditionally portrayed as robed skeletons wielding scythes. Caribou used a simple scythe with a wooden shaft, but it was easily broken by Pekoms.

Maul
A maul (モール) is a heavy, often spiked, hammer head that is mounted on a shaft of varying lengths. Naguri was seen wielding a long-shafted maul to take down a bear, and in the past fight against other pirates. Dosun wielded a gigantic hammer that was ultimately shattered by Tony Tony Chopper.

Unidentified

 * The Alabasta guards had an unknown type of polearm which has a fan-like head. However, this does not resemble any known polearm head. The closest polearm it resembles is the Chinese monk's spade.
 * Brahm of the Tsumegeri Guards also has a strange polearm of unknown origins. The closet the tip resembles is a sasumata, which was a polearm used for catching thieves, however, Brahm's pole arm has two crescent blades that would make such an act impossible. Possibly, they are battleaxes.
 * The executioners who killed Gol D. Roger used polearms that closely resemble nagamaki, except the blade is double edged and straight.
 * Noland did not have the same type of polearm used to execute him, instead his executioners used polearms that more closely resembled glaives.

Trivia

 * At least two of the Straw Hat Pirates, Monkey D. Luffy and Nami are confirmed polearm wielders, though Luffy has since discarded using them.
 * Luffy, Ace, and Sabo all wielded polearms in their youth, although Luffy and Ace would later discard using them when they got older preferring to fight unarmed with their Devil Fruit powers. Sabo is the only one of them to continue using them, even after obtaining the power of Ace's Mera Mera no Mi.