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 idea of attaching a weapon onto a long shaft is an old one, as the first spears date back to the Stone Age. 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 then most weapons and serve a varity 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 apsect of the weapon is on the furthest end of the pole where usually a blade is held for striking. The main offensive sance of a polearm user is therefore usually focus forward on the bladed end, the idea is to strike down the foe before they come anyway near the user and it is often difficult to change fighting stance should they loose, with the only exceptions being the staff branch of pole arms. Pole arms also became useful when horseback riding became a stability of Europeon armies as they were effective at fighting the horseman whereas a sword was useless or alternatively some were designed to pull mounted the riders off their steed. Others like the halberd and trident were designed to fight other polearms. Polearms such as the glaive even earnt the respect and reputation to be considered "superior" to other forms of hand to hand combat.

Pole Arm users were most effective in a army based unit, as they created a wall of spikes that reached out and moved forward closing in on a foe. The sheer number of pole arms also effectively outweighed the defensive weakness of the pole arm, as the most problematic issue with a pole arm is its lesser effective nature when a foe has broken through the reach of the poles end. A single pole arm user was often not as effective as a massed army.

At its core, pole arms combatants are relatively easy to train while the weapon itself is cheap to produce; this was the reason why pole arms continued to be used throughout history until the introduction of firearms rendered the weapons ineffective. However, if the bayonet of a modern rifle is mounted onto its gun, then the gun also effectively becomes classified as a pole arm as well as a firearm.

In One Piece, pole arm 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 seperated 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 specialised tips of the Halberds.

Staves
Staves have a varity 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. In some countries, stick fighting is a form of self-defence against wild animals and intruders, as everyday objects like a broom could instantly be used as defensive weapons. Stick Fighting is not a method of pole arm fighting and only fighting staves fall under the pole arm classification.

Bō
It is a Japanese long staff weapon which is typically around 6 ft (1.8 m) long, used in Japanese martial arts, in particular Bōjutsu. Related staff weapons are the jo which is 4 ft (1.2 m) long and the hanbo or hambo (half bō) which is 3 ft (0.91 m) long.

When she was first seen, Nami used a bō 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 bō, albeit made from gold.

Spear
The spear was often the cheapest of the polearms to produce and at its core could be little more then a long wooden pole with a point sharpened out of the end, more advanced spears had pieces of flint or metal on the spear head. There are two types of spear; those are designed for thrusting and those that are designed for throwing. They are also amongst some of the oldest and simplest weapons in the world and have been made by humans since their early days. Spears are not just produced by humans; several species of apes were also witnessed using "spears" for hunting.

Members of the Shandian 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 captian'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 is a particular branch of spears, usually with three points at the end and designed for thrusting (note; it is not a form of pitchfork nor are pitchforks counted as tridents). The trident is used both for fishing and is a military weapon. For fishing, barbed tridents are used to snear the fish on the point. For fighting, the Trident was designed to catch other types of weapons in the prongs, the idea was to first disarm the foe and once they were disarmed could then be stabbed by the tridents 3 prongs.

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 won't work on Luffy. King Neptune uses a trident, as well as Hody Jones, Prince Fukaboshi and the Ammo Knights.

It is a little difficult to tell if Impel Down guards can be placed into this category along with their higher ranked officers. The weapons they used has an appearance that was based on popular depictions of the devil holding a pitchfork. However, they were not a normal design of pitchfork and had barbs, making them more like tridents. A note is however that the popular depiction of the devil they are based on gets its pitchfork in the first place from early christians, who used a pitchfork or trident as a symbolic method to demonize pagan gods such as poseidon to put them off of worshipping the old Gods by striking fear into their hearts. Since Oda referenced depictions of hell within Impel Down, he at least was referencing the symbol of the pitchfork, however, it in unclear if he knew the origins of the symbolic Devil depiction. Thus it is unclear whether they are truely meant to be pitchforks (which would dismiss them as a possible polearm despite their usage) or tridents or perhaps even a combination of both which is what their weapons resemble.

Lance
Speed Jiru fights using a lance and shield. A lance is a type of long spear that was traditionally used by mounted warriors suich as europeon knights and were much heavier then other types of polearms. They were built for endurance so they did not break so easily and could not be thrown like other spear types could be. They took advantage of the horses strength and speed, they weere most effective when the horse was charging, but were useless at close quarters leaving the horseback rider having to dispose of his lance to draw a sword or mace to fight with. At Thriller Bark, some of the General Zombies were seen using lances as well. Epoida was seen wielding a double headed lance.

Halberd
The halberd 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 for grappling mounted combatants. The halberd was 1.5 to 1.8 metres (5 to 6 feet) long. It is a highly versatile type of polearm and relatively cheap to produce. The point of this pole arm made it better suited for dealing with other types of pole arm. It became a favoured weapon in Europeon armies during the 15-18th century.

Bisento
Whitebeard was seen using a heavy halberd called a bisento. 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.

Naginata
Hannyabal was seen using this type of halberd. A naginata consists of a wooden shaft with a curved blade on the end; it is similar to the Chinese Guan Dao or European glaive or Russian sovnya. Usually it also had a sword-like guard (tsuba) between the blade and shaft and was traditionally used by warriors of the Samurai class. Hannyabal's Kessui however was a double bladed type of Naginata, which is not normal for the Naginata to have.

Maul
A maul is a heavy, often spiked, hammer head that is mounted on a shaft of varying lengths. They are very effective at smashing or puncturing armour, and the spiked versions were also used to drag horsemen of their mounts. Naguri was seen wielding a long-shafted maul to take down a bear, and in the past fight against other pirates.

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 closet 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 to cresent blades that would make such an act impossible.
 * The executioneers who killed Gol D. Roger used polearms that closelty 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.