Luffy D. Monkey

Luffy D. Monkey (ルフィ・D・モンキー, Rufi D. Monkī), also known as "Straw Hat" Luffy (麦わらのルフィ, Mugiwara no Rufi) and commonly as "Straw Hat" (麦わら, Mugiwara), is one of the main protagonists of the Fairy One Piece Tail series. He is the son of the famed pirate Rex D. Monkey, nephew of Revolutionary Army's commander, Dragon D. Monkey, the grandson of the famed Navy hero, Garp D. Monkey, the sworn younger brother of late "Flame Fist" Trace D. Portgaz, Team Natsu members: Natsu Dragneel, Gray Fullbuster and Erza Scarlet, and Revolutionary chief of staff Sabo, and the foster son of Makino and a mountain bandit, Dadan Curly.

Luffy is a pirate and his lifelong dream is to becoming the King of the Pirates by finding the legendary treasure that was left behind by the late King of the Pirates and captain of the Roger Pirates, Roger D. Gol. He believes that being King of the Pirates means having the most freedom in the world. He has eaten the Gum-Gum Fruit, which gives the consumer's body the properties of rubber. As the founder and captain of the Straw Hat Pirates, he is the first member of the crew, one of its top three fighters.

Luffy, is one of the certain people, who has a worldwide reputation for causing trouble, challenging the Seven Warlords of the Sea, the Navy, and even two of the Four Emperors (Big Mom and Kaido), additionally committing felonies and actions which were deemed threatening by the World Government. Furthermore, in the majority of these confrontations, he emerges as the victor. He has gained a reputation for being "reckless", "going too far" and, in some cases, "insane", after causing a war incident that destroyed all of Enies Lobby, assaulting a World Noble at Sabaody Archipelago, entering and escaping from Impel Down, and even joining the Battle of Navyford.

He is, therefore, infamous for being the only known pirate to not only deliberately attack the three most important government facilities, but also escape from all of them alive. The additional fact that he punched a World Noble with full knowledge of the consequences, as well as his heritage, has caused Luffy to be labeled as a "Dangerous Future Element", earning the wrath of Fleet Admiral Sengoku and Sakazuki and Navy Headquarters, making the Navy among his greatest enemies.

These acts, among other things, have given him his current bounty of 400,000,000 berries, one of the highest past or present bounties in the series. Having had a bounty of 300,000,000 berries prior to his arrival at the Sabaody Archipelago, Luffy was one of eleven rookie pirates who has been referred to as the "Eleven Supernovas", pirates with bounties over 100,000,000 berries to have reached the Red Line. He is also one of twelve pirates referred to as the "Worst Generation" (formerly known as the "Eleven Supernovas").

"My name is Luffy, and I'm going to be King of the Pirates!"
 * —Luffy D. Monkey.

Appearance & Biography

 * Voice Actor: Colleen Clinkenbeard (English), Mayumi Tanaka (Japanese), Not Known (Italian), Not Known (Spanish), Not Known (German), Not Known (Finnish), Not Known (Korean), Not Known (French), Not Known (Latin American Spanish)

Biography
Captain of the Straw Hat Pirates. With a dream in his heart, Luffy Sails the open seas! He'll gladly risk his own life for his friends and Beliefs! He ate a Paramythia Curséd Fruit, “Gum-Gum Fruit”, he became a rubber human and with these abilities, his entire body can stretch and expand like rubber.

Raised with his sworn brother Trace in Fushia Village of the East Blue. To fulfill his promise to his father and the famous pirate, Rex D. Monkey, and to achieve his goal is to find the One Piece and become King of the Pirates, he set out for sea. After the Battle of Navyford, he apprenticed and trained for 2 years under Rayleigh Silvers and learned how to use the 3 Haki at will.

With the crew he has met during his adventures at sea, he sets out for the Grand Line. His weaknesses are that he can’t swim due to the side effects of the Devil Fruit and that he is easily deceived. His favorite food is meat.

Appearance
Luffy is renowned for his trademark straw hat (from which he gets his nickname "Straw Hat" Luffy), which was lent to him when he was young by his father and one of the legendary pirate captains, Rex D. Monkey, who in turn received it from Roger D. Gol. He wears short, blue trousers with cuffs, sandals, and a sleeveless red vest. Luffy also has a scar with two stitches underneath his left eye (which he earned by stabbing a knife under his eye to show his father and Shanks that he was tough), short, messy black hair and black eyes. Appearing to be scrawny underneath his shirt, he has a surprisingly well-built physique. He is quite short since he appears dwarfed by most individuals in the series (though it must be noted that characters in One Piece are often very tall for real life standards).

Pre-Timeskip
Similar to most of his male crewmates, Luffy has the same outfit throughout most of the series, as opposed to the rest of the crew (especially Nami and Robin Nico), who change frequently. Luffy may wear a different outfit to suit the climate of an island (like a hooded parka on Drum Island or desert robes in Alabasta), but will switch back to his trademark red vest and blue shorts after the adventures on that island are over. Despite this, he will wear his usual outfit in different colors and has been known to sport other miscellaneous items on his person from time to time.

No matter where he is, Luffy wears his Straw Hat through absolutely everything, though at the start, the hat was prone to getting knocked off his head easily, forcing Luffy to either put it aside or have someone hold onto it during fights. From the Alabasta Arc onward, he has gotten a string strap for it, which was sewn on by Nami, allowing the hat to hang from his neck during fights.

During his return to Navyford to give a silent prayer, Luffy was briefly shown with four characters written on his right arm spelling 3D 2Y, with the 3D crossed out to symbolize that the Straw Hat Pirates and Fairy Tail should meet up in 2 years (2Y) rather than the 3 days (3D) as planned after fleeing from Kuma Bartholomew.

Outfits

 * During the Drum Island Arc, he wore two parkas, the first being a dark red parka with fur on the cuffs, hood, and hem, and then a checkered, hooded parka with the colors white, orange and bright yellow, which Nami wore in the beginning.


 * During the Alabasta Arc, he wore desert robes consisting of a dark red robe with three white rings decorated along both of the sleeves and a light blue wrap over his head.


 * During the Skypiea Arc, he wore a black wristband around his left wrist with a white bangle over it.


 * During the Long Ring Long Land Arc, Luffy wore an afro on his head, dark red shorts, and red bandages on his feet, getting an image of a blue flaming skull and crossbones painted on his chest as well, when he was fighting Foxy.


 * During the Enies Lobby Arc, he wore black shorts which had more pockets than his blue shorts (However, Luffy noted that he couldn't fit his meat in them.).


 * During the Post-Enies Lobby Arc, Luffy wore a white T-shirt with the Galley-La Company emblem on it in red; red liners around the top, shoulders, and collar; and navy blue shorts.


 * During the Thriller Bark Arc, he wore an orange vest and red shorts. After the battle against Moria in Thriller Bark, Luffy wore a dark decorated, jewelled armband around his left bicep, given to him by Nami. This armband was later revealed to be a map that leads to Captain John's lost treasure, which Buggy sought for some time - leading to Luffy handing the armband in for Buggy in exchange for his services at helping him navigate through Impel Down.


 * During the Sabaody Archipelago Arc, in the manga he wore a blue vest, and with dark blue shorts.


 * During the Amazon Lily Arc, Luffy wore a light blue vest with red shorts.


 * During the Impel Down Arc, Luffy wore his outfit from his stay on Amazon Lily until after his fight with Magellan, at which point he replaced his light blue vest with a bright yellow vest given to him by Inazuma.

Post-Timeskip
After those two years, only a few things have changed. Luffy now wears an open up, long-sleeved red cardigan with four buttons (which shows the X-shaped scar covering most of his chest he received by then-Admiral Akainu, similar scar his father has), with a yellow sash tied around his waist, somewhat reminiscent of Roger D. Gol's outfit. He has grown slightly taller, and is shown to be significantly more muscular due to his training. This can be seen in his slightly thicker neck, more pronounced deltoids, and better-defined chest.

Outfits

 * During the Punk Hazard Arc, Luffy wore a long winter coat with red and white horizontal strips, along with yellow ear muffs, which he stole from one of Brownbeard's Centaur Patrol Unit.


 * During the Dressrosa Arc, Luffy wore an open, short-sleeved shirt with a sunflower pattern, along with his standard blue shorts and yellow sash. He also wore a fake beard. Upon entering the tournament for the Flame-Flame Fruit in the Corrida Colosseum, he wore viking-style armor, complete with a sword and shield, until it was stripped from him due to violation of the weight restriction. Upon revision to the weight restriction, he added a cape and wore the same viking style helmet he wore previously. Along with his registration number '0556' on the back of his shirt, obscured by his cape. When he recovered after his battle against Doflamingo, Luffy wore a red tank top along with his standard shorts in brown.


 * During the Totto Land Arc, Luffy wore an open, fancy white cardigan with puffy sleeves along with his standard shorts in red. He also had a decorative scarf wrapped around his straw hat after landing at the Seducing Woods, though he appears to have lost it during his battle with Cracker Charlotte.


 * Hair Color: Black
 * Skin Color: Not Known
 * Eye Color: Black
 * Age: 7 (Chapter 1), 17 (debut), 19 (after timeskip)
 * Birthday: May 5th (Children's day)
 * Height: 253 cm. (8'3½")
 * Weight: Not Known

Friends/Allies

 * Straw Hat Pirates
 * Zolo Roronoa
 * Nami
 * Usopp
 * Sanji Vinsmoke
 * Chopper Tony Tony
 * Franky
 * Genzo
 * Dorry
 * Mr. 2 Bon Clay
 * Rayleigh Silvers
 * Inazuma

Family

 * Rex D. Monkey (father)
 * Dragon D. Monkey (uncle)
 * Garp D. Monkey (grandfather)
 * Makino (1st foster mother)
 * Dadan Curly (2nd foster mother)
 * Natsu Dragneel (adopted brother)
 * Erza Scarlet (adopted sister)
 * Gray Fullbuster (adopted brother)
 * Trace D. Portgaz (adopted brother; deceased)
 * Sabo (adopted brother)

Neutral

 * Buggy
 * Chaser Smoker
 * Mr. 3
 * Foxy
 * Imitatia (as Michelle Lobster)
 * Duval
 * Motobaro

Enemies

 * Alvida
 * Navy
 * Fullbody
 * Buggy Pirates
 * Richie
 * Mohji
 * Black Cat Pirates
 * Kuro
 * Django
 * Eneru
 * CP9
 * Lucci Rob
 * Impel Down
 * Magellan
 * Minotaurus
 * Blackbeard
 * Big Mam Pirates
 * Big Mam
 * Cracker Charlotte
 * Tesoro Gild
 * Spartan
 * Doflamingo Don Quixote

Abilities and Powers
As captain of the Straw Hat Pirates, Luffy D. Monkey has immense physical strength, and is capable of lifting up large boulders, breaking stone, shattering steel with his bare hands, pushing apart large buildings and shoulder flipping a huge man; his strength was further proven when he effortlessly stopped a stomp from Doflamingo Don Quixote, a tremendously strong man who is twice Luffy's size, with only one foot from an angle with no leverage.

Physical Abilities
His endurance and durability is incredible; taking continuous, deadly assaults from powerful opponents that would have killed a normal person easily in most of his fights, yet still being able to stand up and continue fighting effectively. Over the course of the series, he progressively becomes able to take more and more punishment and fight for longer periods of time without tiring. By the events of the Totto Land Arc, his endurance and durability have grown to the point that he is able to fight a grueling battle with Cracker Charlotte for 11 straight hours (while activating Gear Fourth at least twice), and after only a brief nap, endured a vicious beating from Sanji's Diable Jambe enhanced kicks only to be back on his feet shortly thereafter and still capable of using Gear Second when attacked by Big Mom's army. Furthermore, he then goes on to rampage through the Whole Cake Chateau, defeating dozens more of Big Mom's underlings even while being considerably injured, extremely fatigued, and near-death from starvation.

Luffy also possesses tremendous speed, agility, and reflexes to match his strength and endurance. In fact, on more than one occasion, Luffy was able to anticipate moves and counter attacks that would normally be beyond his field of vision due to his extremely sharp reflexes. He is also shown to increase in strength quite dramatically in a short period of time, most noticeably being the fight against Minotaurus, where the first time it took the combined efforts of Mr. 2, Mr. 3, and Buggy just to beat him, but the next time, Luffy defeated him with a single "Gum-Gum Jet Blast".

His vast strength is only exceeded by his enormous willpower, as demonstrated on several occasions throughout the series, most noted of all in the Thriller Bark Arc when he manages to take in 100 shadows without passing out, compared to normal humans, who can only take in 2 or 3. This willpower even lets him survive far beyond what normal people are capable of, as demonstrated when he was poisoned very far beyond what a human is capable of surviving, only living on despite his critical condition through sheer willpower. This is also shown when he survives through Ivankov Emporio's "Healing Hormones" ability, which even with a slim chance of surviving had not only survived the endeavor, but made a recovery in twenty hours when the normal time for the healing procedure is two days. This was later shown with Hawkins Basil' "fortune telling" ability, as despite doing it multiple times, he could never get Luffy's chances of survival to reach 0.

He also possesses extraordinary jaw strength, as seen in the Orange Town Arc in the manga, where he had almost chewed through the metal bars of the cage Buggy put him in. In the following arc, he shattered Django's steel chakram with his teeth alone (anime). He also ate the cage that Moria Gecko put him in, and managed to give Lucci Rob a small bite wound, as well as break the steel chain used to bind Nami (in Franky's body) after the timeskip. His greatest feat in this area, however, was that he managed to make Jimbei, who is known to have an extremely high tolerance towards pain, yell out in pain when he bit the mermen's arm.

Luffy is also shown to be extremely agile. Early on in the series, Luffy is seen being able to react to foes faster than him, like Kuro, Arlong, Bellamy, and Eneru. After learning the CP9's Shave technique to enhance both speed and strength, he became even more so. After the timeskip he has become even faster, being able to dodge attacks even while in Gear Third, and even creating enough friction while running at full speed to set the ground on fire.

Fighting Style
Luffy's fighting style consists of adept hand-to-hand combat, supplemented with his physical prowess and the abilities of the Gum-Gum Fruit. Such skill allows him to hold his own against combat specialists like Lucci Rob. Unlike Zolo or Sanji, Luffy's fighting style is completely self taught; it follows no particular code of honor, and so if necessary, he will attack women or animals, hit below the belt, attack his enemies even if they have their backs turned or are otherwise unprepared or unsuspecting, use enemies as human shields and even bite his opponents. While fighting, Luffy has been shown to be highly adept at improvising, and regularly comes up with creative counterattacks and unusual techniques]] to use against his enemies. This however leads both enemies and allies alike to wonder if Luffy is taking the fight seriously, especially when he comes up with ridiculous and over the top moves (like Crocodile when Luffy became Water Luffy), which prompts Luffy to respond that he's always serious.

When Luffy fights, he relies heavily on his instincts, which, interestingly enough, are mostly correct. Even as early as the Arlong Park Arc, after getting bitten he managed to escape with his arm still in one piece by slamming Arlong's head to loosen his jaw to get it out instead of simply pulling it. He picked out the real Mr. 3 from a bunch of wax look-a-likes on a hunch. He also destroyed Eneru's "Raigo" using the gold ball as a conductor, but according to Oda he had no real idea what he was doing and was acting out of instinct. Before even learning Observation Haki, Luffy could easily dodge any attack by relying on his instinct as shown in his battle against Eneru and Lucci Rob.

During his childhood, Luffy seems to have at least become competent with a staff, as he is seen using one against a variety of opponents.

He also appears to be intelligent enough to at least understand fundamental concepts, such as rubber being a natural insulator, which might be why he did not bother ducking out of the way of Eneru's lightning attacks as it would have been pointless because of his immunity. He also was able to develop new techniques such as "Gear Second" and "Gear Third", using logical concepts and knowledge of rubber and its properties. While easily noticeable as the least strategic member of his own crew, largely due to his tendency to simply barge in head-first into battle (often without any kind of battle plan or even any knowledge of his opponent's abilities), Luffy is a highly adaptive combatant. He is constantly coming up with ways to keep ahead of his foes, either by taking advantage of his own strength and Curséd Fruit powers or utilizing the opponent's own strengths (along with their weaknesses) against them. This causes even warriors long considered unbeatable to have trouble keeping up. Also, even if most of the time he acts instinctively, in some cases Luffy has shown to be intelligent enough to give some orders to his crewmates in the wake of making a strategy or simply making things go as he prefers. This usually ends up being an advantage for the crew.

After the timeskip, Luffy has demonstrated more intelligence during the heat of battle, as he was able to use Law Trafalgar's powers to his advantage and even fool a Warlord as cunning as Doflamingo into being swapped out so Luffy could land a blow on him. He also exploited Cracker's Curséd Fruit abilities, making use of the immense hardness of Cracker's own Biscuit Soldiers to inflict massive damage on the latter.

Curséd Fruit

 * Main article: Gum-Gum Fruit

The Gum-Gum Fruit (ゴムゴム実, Gomu Gomu Mi), a Paramythia-type Curséd Fruit, which is one of the rare and legendary ones that was eaten by Luffy, makes his body became like rubber, giving him the gained extraordinary ability powers to stretch and attack long distances, which is makes him a Rubber Human (ゴム人間, Gomu Ningen).

Having undergone intense training for over ten years, Luffy is now able to supplement his stretching powers with immense strength, agility, and creativity in combat. His fighting style is largely improvised, and thus relies heavily on his Curséd Fruit powers. It should also be noted that Luffy cannot automatically stretch his limbs out (like superheroes with stretching powers, (i.e: Mr. Fantastic or Plastic Man), and since his body acts much like an actual rubber band, he has to throw some force into his punches in order for his limbs to stretch out. It should be noted that he has somehow managed to do it automatically (much like the aforementioned superheroes) after the timeskip. However, he has been shown to be able to hold his limbs outstretched for a long period of time, as seen when he reaches his arm out about half a mile down to try and retrieve Usopp from falling through the Sea Clouds.

Luffy regularly uses his stretching powers in ingenious and creative ways, as he is able to use the malleable stretchiness and elasticity of his limbs to gain tremendous velocity, and hit his enemies with devastating impacts and blows. His rubber body is also extremely durable and virtually immune to blunt attacks such as bullets (in One Piece, bullets are still round pellets, except for Don Krieg's), punches, and electricity, more often than not, bouncing off his body harmlessly or canceling out the attack. It has even become a running gag that people find out the hard way that Luffy is made of rubber when they shoot at him, only to have the bullets bounce back at them.

Another running gag is that whenever Luffy's body is in a dangerous situation that would kill a normal person, he simply states that "he's made of rubber, so it's okay", or acts like it is a small problem despite that person trying to kill him, such as being shot in the heart. However, he is still normally susceptible to sharp objects such as swords and knives as well as nonphysical attacks like heat, cold, dehydration, and poison (though after the timeskip, Luffy has been shown a strong immunity to poison due to his fight against Magellan in Impel Down). Not only can he use his stretchiness to increase the range and strength of his attacks, but on some rare occasions he can also use his stretched limbs to help restrain and even control weaker foes like puppets (to fight for him).

Techniques
The named techniques that are used by Luffy that involve the Cursed Fruit are as follows:
 * Gum-Gum Blast (ゴムゴムブラスト, Gomu Gomu Burasuto): This is Luffy's signature attack; he stretches his arm back then throws a devastating punch. In other words, it is a standard straight punch, augmented with stretching. This attack can be used from short to long range. Luffy would typically increase the striking reach of fist by 'charging up' by means of first repeatedly swinging his un-stretched punching arm around before using the spinning force to both stretch his arm to its limits, and to maximize the hitting power. Its name comes from Luffy's claim to Shanks that his punching arm is "as powerful as a quick blast!" The first version of this is seen when Luffy tried fighting against Ace and Sabo when he was a child but it kept failing. Trace asks for the point of his fruit, and Luffy replays the move in his head, saying it does not come out the way he wants. This was first successfully seen being used on the Lord of the Coast after ten years of training in the manga, while in the anime, it is first seen being used against Alvida. In the second version of Romance Dawn, Luffy used a technique similar in concept to this attack against Spiel.


 * Gum-Gum Rocket (ゴムゴムロケット, Gomu Gomu Roketto): Luffy's main method of traveling long distances fast. He stretches out one of his arms or both and grabs a handhold, then retracts them, projecting himself high into the air at high speeds, over great distances, or even into an opponent. This was first used when Luffy was a child, along with Trace and Sabo, battling against the king of Mt. Colubo, a giant tiger. Trace had given this attack its name as seen when Luffy had launched Trace forward to attack the tiger in Episode 499. This technique is often times reckless especially if not done properly as Luffy could accidentally propel himself into a body of water or worse. Indeed, Luffy has little to no control after launching himself, being unable to change directions in mid-flight, and is only able to (barely) decelerate before landing. This was first seen being used to propel Luffy to the top of the Navy Base in Shells Town in the manga. In the anime, it was first seen being used to crash into Alvida's crew. This technique is also capable of landing devastating attacks against larger opponents as shown against Dorry. A humorous usage of this "attack" was accidentally against Ace and Chaser in a Restaurant, who are both Logia Users but did not have the reflex to counter the Rocket.


 * Gum-Gum Whip (ゴムゴム鞭, Gomu Gomu Muchi): Luffy stretches his leg and kicks in a wide circle, striking multiple foes. This was first seen being used against a group of Navy men in Shells Town.


 * Gum-Gum Hammer (ゴムゴムハンマー, Gomu Gomu Hanmā): Luffy stretches out his arms while twisting them, then takes hold of his opponent. He then untwists them, rapidly spinning his opponent, while bringing him crashing to the floor. This was first seen being used against Richie after he and Mohji destroyed Chouchou's master's store.


 * Gum-Gum Balloon (ゴムゴム風船, Gomu Gomu Fūsen): A technique where Luffy inflates himself rapidly through his mouth, further increasing his resistance to blunt attacks. With his inflated body, Luffy is capable of deflecting projectile attacks back at his attackers. This is not necessarily always an attack as Luffy can also use this technique for other purposes aside from deflecting projectiles such as escaping Chaser's Smoke Snake technique or using himself as a cushion when his ship is in for a hard landing. This can also prevent Luffy from sinking under water, making him bounce off the surface. This was first seen being used against one of Buggy's cannonballs after Luffy insulted Buggy.


 * Gum-Gum Fist (ゴムゴム拳, Gomu Gomu Ken): Luffy grabs an object behind his opponent and pulls himself towards them. He then stretches out his other arm and clotheslines his opponent. This was first seen being used against Buggy.


 * Gum-Gum Double Barrel (ゴムゴムダブル・バレル, Gomu Gomu Daburu Bareru): Luffy stretches both his arms far back, and then hurls them forward, striking his opponent with both instantaneously with a double open palm strike with both hands, that frequently sends the recipient(s) flying off the other direction. This is usually used as a finishing move, he often prefers to do it at point-blank range, sometimes running up to his opponent as he's charging it. This was first seen being used to defeat Buggy.


 * Gum-Gum Rapid Fire (ゴムゴムラピッドファイヤー, Gomu Gomu Rapiddo Faiyā): Luffy uses his stretching ability to bring his fists forward repeatedly in a blurry, rapid barrage of strong punches that creates the illusion of him having multiple arms, however he does not actually grow more arms so he can still be stopped by an opponent fast enough (as Eneru, Lucci Rob and Usopp have demonstrated). This was first seen being used against a group of Black Cat Pirates after being accidentally hypnotized stronger by Django.
 * Armament Hardening: Gum-Gum Rapid Fire (武装硬化 ゴムゴムラピッドファイヤー, Busō Kōka: Gomu Gomu Rapiddo Faiyā): Luffy uses Armament Haki to harden his fists, greatly increasing the strength of his standard Gum-Gum Rapid Fire attack.


 * Gum-Gum Spear (ゴムゴムスピア, Gomu Gomu Supia): Luffy holds his feet together (with the bottoms of each touching each other) and kicks with both simultaneously via his toes (giving off the image of an actual spearhead). This was first seen being used against Kuro after Luffy dodged his attack.


 * Gum-Gum Bell (ゴムゴム鐘, Gomu Gomu Kane): While latched onto an enemy, Luffy stretches his neck backwards, then snaps it back for a devastating head butt to the opponent's face. It is named for the fact that if one were to hit another's head hard enough, they could make them hear bells. This was first seen being used to defeat Kuro.
 * Head Armament: Gum-Gum Bell (頭武装 ゴムゴム鐘, Atama Busō: Gomu Gomu Kane): Luffy uses Armament Haki to harden his forehead and gives a powerful stretched headbutt to the opponent. A much stronger version of his standard Gum-Gum Bell attack that was able to shatter the iron shields of the New Merman Pirates' Iron Shell Squad.


 * Gum-Gum Slingshot (ゴムゴムパチンコ, Gomu Gomu Pachinko): Luffy grabs hand and foot holds, then intercepts a projectile, stretching back and firing the projectile back at its origin. In the Warship Island Arc he used this move to stop a lot of Marines and throw them into the water. This was first seen being used against the cannonball that Fullbody fired at Luffy; whereas in the manga, Luffy bounced it back with a Gum-Gum Balloon.


 * Gum-Gum Giant Scythe (ゴムゴム大鎌, Gomu Gomu Ōgama): Identical to Gum-Gum Fist, but he uses both arms for the rocket and the clotheslining. This was first seen being used on a group of Krieg's pirates that were attacking the Baratie.


 * Gum-Gum Burst (ゴムゴムバースト, Gomu Gomu Bāsuto): Luffy stretches one arm, far behind him while running, then snaps it back to deliver a short-distance, one-fisted powerful blow to an opponent. This was first seen being used on Don Krieg.
 * Armament Hardening: Gum-Gum Burst (武装硬化 ゴムゴムバースト, Busō Kōka: Gomu Gomu Bāsuto): Luffy stretches one arm, far behind him while running, uses Armament Haki to harden the fist at the end of his stretched arm, then snaps it back to deliver a powerful short-distance, one-fisted blow to an opponent's abdomen.


 * Gum-Gum Giant Hammer (ゴムゴムギガントハンマー, Gomu Gomu Giganto Hanmā): Similar to Gum-Gum Hammer, but he performs it using the feet and legs instead of hands and arms while in mid-air. He performed this while he was trapped inside Krieg's net, sending the latter crashing into Baratie's front porch. This was first used against Don Krieg.


 * Gum-Gum Pinwheel (ゴムゴム風車, Gomu Gomu Kazaguruma): A technique that was used once in the Arlong Arc. Luffy planted his feet into the ground to steady himself, then twisted his body around tightly. He then grabbed hold of Arlong's pet Mohmoo and unwound, spinning the Sea King around rapidly to crush the Mermen surrounding him. After spinning around several times, Luffy then let go of Mohmoo and threw him far away. While it took out most of Arlong's Mermen, it however had the disadvantage of getting Luffy's feet stuck in the ground. This was first used against the Arlong Pirates. This rather reckless move was inspired by the sight of the pinwheel on top of Genzo's hat by Luffy. "Kazaguruma" can be translated as either "windmill" or "pinwheel". Luffy also used an alternate version of this move where he merely twists his mid-section as he unwinds with both arms out to smack around himself 360 degrees; another version is also during his fight with Lucci Rob, where he simply grabs his target and twisting his mid-section before unwinding, and throwing his opponent. Both these alternate versions do not involve planting his feet on the ground prior.


 * Gum-Gum Shield (ゴムゴム盾, Gomu Gomu Tate): Luffy grabs the fingers of one hand with the other, and stretches them before his face to block blades that pass between the fingers. This was first seen being used on Arlong.


 * Gum-Gum Finger Net (ゴムゴム指網, Gomu Gomu Yubi Ami): Luffy entwines his fingers making a net like shape and then stretches out his fingers making a larger net in an attempt to trap his opponents. This was first seen being used on Arlong.


 * Gum-Gum Axe (ゴムゴムアックス, Gomu Gomu Akkusu): Luffy stretches one leg high into the air, then brings it crashing down via a high-gravity stomp on an opponent or structure, for massive damage, strong enough to destroy large buildings and ships in a single hit. Usually when Luffy executes this attack, after stretching out his leg, he brings his foot down immediately below him, however sometimes (mainly in the anime and in the video games) he keeps his leg extended and brings it down, like a vertical version of Gum-Gum Whip. This was first seen being used to defeat Arlong. It was also used to destroy Crescent Moon Galley's ship in the First Romance Dawn although not named. The kanji's literal reading is "senpu" (lit. war axe), a Japanese term for a battleaxe, which contradicts the main reading of the attack as "ono" (which only refers to an axe by itself).


 * Gum-Gum Screw (ゴムゴムネジ, Gomu Gomu Neji): Luffy grabs onto a large, spinning object that is shot at him while holding onto a foothold, twists his arms and legs as if to do a Gum-Gum Giant Scythe while the force of the object propels him further to his ability's limit, then slams the object into a foe while spinning. This was first seen being used against Bear King in the second Fairy One Piece Tail movie.


 * Gum-Gum Grab (ゴムゴムグラブ, Gomu Gomu Gurabu): A technique wherein Luffy stretches his arm out to catch something. This was first seen being used to catch what Luffy assumed to be fish. Instead of catching fish however, Luffy caught an unconscious Apis adrift on her boat. The recoil of this technique is somewhat reckless as Luffy's arm knocked Zolo off the Merry Go as Luffy reeled it back in.


 * Gum-Gum Suspension Bridge (ゴムゴム吊橋, Gomu Gomu Tsuibashi): A technique wherein Luffy turns himself into a make-shift bridge by laying his rubber body across a gap. This was first seen being used to help Nami get across a wide gap in Warship Island.


 * Gum-Gum Lasso (ゴムゴム投げ縄, Gomu Gomu Nagenawa): A technique wherein Luffy entwines himself around something, and then stretches his arm to grab an object. This was first seen being used when the Merry Go was going through a typhoon to get to the Lost Island. Luffy entwined his body to the ship's mast and stretched out his arm to lasso Ryu's raft.


 * Gum-Gum Flower Arrangement (ゴムゴム生け花, Gomu Gomu Ikebana): A technique in which Luffy grabs hold of the Merry Go's mast and slams it into his opponent. This was first seen being used on Laboon. The name is derived from the fact that the way the mast is slammed resembles typical Japanese flower arrangements.


 * Gum-Gum Club (ゴムゴムクラブ, Gomu Gomu Kurabu): A technique that Luffy had to temporarily come up with while on Little Garden. Mr. 3 uses the powers of the Wax-Wax Fruit several times to wrap a large wax cylinder around Luffy's feet and then later arm. Instead of slowing Luffy down, Luffy actually uses the wax cylinder to his advantage. Using it like a hammer, he first destroyed the pole on Mr. 3's wax creation with a cylinder wrapped around his feet. Luffy had then later broke through Mr. 3's Candle Wall and pounded Mr. 3 himself with a cylinder on his arm. The cylinders that bound Luffy's feet and arm both broke upon impact.


 * Gum-Gum Stamp (ゴムゴムスタンプ, Gomu Gomu Sutampu): Luffy stretches his leg out and hits his opponent with the bottom of his foot, leaving an imprint, or "stamp", of his sandal. This was first seen being used to finish off Mr. 3.


 * Gum-Gum Crossbow (ゴムゴムクロスボウ, Gomu Gomu Kurosubō): Taking hold of his opponent from behind, Luffy repeatedly twists his torso vertically around his hips before grasping them with his feet and then rapidly untwisting, creating a snapback that sends his opponent flying upwards. This was first seen being used against Wapol.


 * Gum-Gum Twister (ゴムゴムツイスター, Gomu Gomu Tsuisutā): Used against a giant sea bird in the anime, Luffy jumps into the air and does a Gum-Gum Hammer, with his hands grabbing the bird's beak to prevent it from attacking him, spinning the bird around in a cyclone before slamming down onto Merry Go's deck.


 * Gum-Gum Give Me Water (ゴムゴム水くれ, Gomu Gomu Mizu Kure): Similar to Gum-Gum Rocket, except Luffy wraps the outstretched arm several times around the target before rocketing towards it. This was first seen being used to get onto Barbarbossa's ship in one of the Alabasta anime filler episodes.


 * Gum-Gum Sand Splitter (ゴムゴム砂土割り, Gomu Gomu Sadowari): While fighting on sandy terrain, Luffy outstretches his arm and skims the surface of the sand to uppercut the opponent from afar.


 * Gum-Gum Spring (ゴムゴムゼンマイ, Gomu Gomu Zenmai): Similar to Gum-Gum Rocket, however he wraps his arm around a round object multiple times, making it very firm, he then spins around the object then suddenly getting shot very far and high in the direction Luffy wants.


 * Gum-Gum Keep Away (ゴムゴムキープアウェイ, Gomu Gomu Kīpu Awei): A joke technique in which Luffy stretches his arm to keep objects away from others attempting to steal it.


 * Gum-Gum Submarine (ゴムゴム潜水艦, Gomu Gomu Sensuikan): Similar to Gum-Gum Blast, but his fist travels underground to uppercut the target.


 * Gum-Gum Munch-Munch (ゴムゴムムンチュムンチュ, Gomu Gomu Munchu Munchu): Luffy stretches his mouth wide open, and attempts to bite or trap his opponent.


 * Gum-Gum Buzzsaw (ゴムゴム丸鋸, Gomu Gomu Marunoko): Luffy grabs his opponent from afar with both arms and winds himself up like with a crossbow. He then kicks off from the ground and spins towards his opponent to deliver a powerful head butt.


 * Gum-Gum Quake (ゴムゴムクエイク, Gomu Gomu Kueiku): Starts off as an ordinary Gum-Gum Blast attack, after which Luffy "twangs" his stretched arm, causing his fist to connect multiple times.


 * Gum-Gum Storm (ゴムゴムストーム, Gomu Gomu Sutōmu): An extremely powerful move and is easily one of Luffy's strongest attacks. Luffy first uses Gum-Gum Balloon and twist his body around tightly, then blows the air out behind him while untwisting to fly in forward while spinning towards an opponent, where he delivers a constant, quicker and faster barrage of powerful punches and kicks somewhat similar to Gum-Gum Rapid Fire, with power greatly enhanced by the momentum of his launch. This attack is so powerful it can also beat strong opponents like Crocodile, when he send him through an extremely thick ceiling of solid bedrock and cause a huge earthquake in Alabasta, and then propel him several hundred feet into the air. This technique can be used going sideways, upwards towards airborn targets, and downwards while Luffy is airborne.


 * Gum-Gum Bungee Jump (ゴムゴムバンジージャンプ, Gomu Gomu Banjī Janpu): When holding onto a ledge while stretched, Luffy retracts his arm to pull him up while hopping along the wall.


 * Gum-Gum Grappling Hook (ゴムゴム鉤縄, Gomu Gomu Kaginawa): Luffy used this to make a way from his ship to another ship. He stretches his arm far to catch the Navy ship and retracts it, just like Gum-Gum Rocket.


 * Gum-Gum Mooring Line (ゴムゴム艫綱, Gomu Gomu Tomozuna): Luffy stretches both of his arms between the ship he is on and the one he wants to go to. By jumping off the ground, he is able to pull himself and passengers to the ship that he is holding onto.


 * Gum-Gum Warp (ゴムゴムワープ, Gomu Gomu Wāpu): A sort of joke move used in the Rainbow Mist. Since the phenomenon creates a wormhole-like effect, Luffy attempts to "rocket" out of it only to end up exactly where he started.


 * Gum-Gum Fireworks (ゴムゴム花火, Gomu Gomu Hanabi): Luffy jumps into the air and spins around rapidly. Then he unleashes a flurry of punches and kicks that go in every direction due to the spinning motion.


 * Gum-Gum Space-Out... (ゴムゴムボー, Gomu Gomu no Bō...): A technique in which Luffy 'switches off' his conscious mind, allowing him to avoid attacks entirely on instinct. This made him immune to Eneru's mind-reading Mantra ability. The disadvantage is that he can neither think nor attack in this state.


 * Gum-Gum Octopus (ゴムゴムたこ, Gomu Gomu Tako): A technique in which Luffy makes his appendages go limp that they resemble the tentacles of an octopus


 * Gum-Gum Octopus Fireworks (ゴムゴムたこ花火, Gomu Gomu Tako Hanabi): Much like Gum-Gum Fireworks except, due to the previous move, Gum-Gum Octopus, his limbs bounce off of walls without losing speed. Because his limbs are limp, Luffy can't predict or control where they will go if they ricochet off of an object, much less the unlucky opponent(s). This is completely advantageous against a Mantra ability user as they also can't predict where Luffy's punches and kicks would come at them.


 * Gum-Gum Drill (ゴムゴムドリル, Gomu Gomu Doriru): Similar to the Gum-Gum Burst, but Luffy twists his arm around as he stretches it behind him and hits the opponent at close range, putting a spin on them.


 * Gum-Gum Yo-Yo (ゴムゴムヨーヨー, Gomu Gomu Yō-Yō): With a gold ball attached to his arm, Luffy holds onto an object and uses the ball to stretch himself so far that when he snaps back he is sent flying into the sky. A variation of this is used with Gum-Gum Balloon during the Enies Lobby saga as Luffy uses it to escape the Navy by jumping down from a build in while still holding on the bouncing back up.


 * Gum-Gum Fireworks: Golden Peony (ゴムゴム花火・黄金牡丹, Gomu Gomu Hanabi: Ōgon Botan): During Luffy's fight with Eneru, he encased Luffy's arm in a Golden Ball he created by melting some gold with his Gloam Paddling technique. With this, Eneru hoped to hinder Luffy's actions. Luffy however, despite burdened with this huge cumbersome object, was able to still move about and use his burden to his advantage in two techniques that he had to temporarily come up with. It is the same as Gum-Gum Fireworks, but with the Golden Ball attached to his arm.


 * Gum-Gum Golden Drill (ゴムゴム黄金ドリル, Gomu Gomu Ōgon Doriru): The same as Gum-Gum Drill but with the Golden Ball attached to his arm. This move possesses much more speed than a regular Gum-Gum Drill in that it creates a Sonic Boom when used. After destroying Eneru's Kingdom Come with the Golden Ball, Luffy used this technique to defeat Eneru and ring the Golden Bell of Shandora. This was so fast that even though Eneru's Mantra ability could detect it, this was too fast for Eneru to avoid. With this technique, Luffy was also able to break the Golden Ball encasing his arm as the ball hit the bell.


 * Gum-Gum Top (ゴムゴム独楽, Gomu Gomu Koma): Luffy wraps an outstretched arm several times around a target, then pulls his arm away suddenly, causing the target to spin out of control.


 * Gum Hook (ゴムフック, Gomu Hokku): Luffy launches an elongated hook, which can hit the enemy’s back due to his stretching ability.


 * Gum-Gum Flail (ゴムゴムフレイル, Gomu Gomu Fureiru): Luffy swings one arm in a circle at high speed, then drives his fist into his opponent.


 * Gum-Gum Cannon (ゴムゴムピキャノン, Gomu Gomu Kyanon): Luffy first stretches both his arms far back, then snaps them back to deliver a long barrage series of quick punches. Luffy also has an alternate version of this move, where he builds up speed with a long series of quick punches, and finishes with a single double-fisted blow. A powerful technique that can pierce strong armor, and, in combination with Zolo's Three-Swords Style, devastating enough to puncture a hole through a massive tidal wave.


 * Gum-Gum Ally Robot (ゴムゴム味方ロボ, Gomu Gomu Mikata Robo): Luffy wraps his arms around a person's limbs in order to manipulate their movements.
 * Ally Robot Punch (味方ロボパンチ, Mikata Robo Panchi): Luffy uses his "Ally Robot" to punch an opponent.
 * Ally Robot Kick (味方ロボキック, Mikata Robo Kikku): Luffy uses his "Ally Robot" to kick an opponent.


 * Gum-Gum Volcano (ゴムゴム火山, Gomu Gomu Kazan): Similar to Gum-Gum Axe, except Luffy's foot is stretched upwards to break through a roof.


 * Gum-Gum Twin Blast (ゴムゴムツインブラスト, Gomu Gomu Tsuin Burasuto): Basically Luffy's normal Blast attack, only with both of his arms instead.


 * Gum-Gum 100,000 Degree Barrel (ゴムゴムの100,000ダグレーバレル, Gomu Gomu no Jūman Degurī Bareru): Basically a regular Gum-Gum Double Barrel technique, but the technique differs a little from a regular Double Barrel technique, however at the moment of impact, Luffy continued applying force to the attack despite his hands being burned by the powers of Achino Don's cursed Fruit, the Hot-Hot Fruit. As a result, Luffy was able practically use Achino's own cursed Fruit powers against him by allowing the heat being accumulated into his arms as he maintains contact with the Don's body to build-up. Thus allowing Luffy to send Achino flying away into his house, Lovely Land.


 * Gum-Gum Belly Talk (ゴムゴムハラギ, Gomu Gomu Haragi): Luffy uses Gum-Gum Balloon and draws a face on his expanded belly and moves it while he dances.


 * Gum-Gum Ricochet (ゴムゴムリコチェット, Gomu Gomu Rikochetto): Luffy uses both of his arms and legs to rapidly having them bouncing on the surface of the area to attack multiple opponents, similar to Gum-Gum Octopus Fireworks.


 * Gum-Gum Rain (ゴムゴム雨, Gomu Gomu Ame): Luffy executes Gum-Gum Balloon as well as twisting his body, using the stored air to launch himself into the air and performs a strong, rapid-fire barrage of punching and kicking attack while spinning. Similar to gum-gum Storm, except he punches and kicks while descending like rain. Another variation of this technique is where Luffy jumps into the air instead without inflating himself beforehand, before performing a puch-kick barrage.


 * Gum-Gum Human Shield (ゴムゴム身代り, Gomu Gomu Migawari): Luffy avoids getting hurt from his opponent by grabbing someone else around him and use them as a human shield.


 * Gum-Gum Rapid Stamp (ゴムゴムラピッドフスタンプ, Gomu Gomu Rapiddo Sutampu): Similar to Gum-Gum Stamp, except he makes multiple strikes with his foot.


 * Gum-Gum Snake Shot (ゴムゴムスネークショット, Gomu Gomu Sunēku Shotto): Luffy uses his Cursed Fruit abilities to launch his arm in a swerving snake-like movement and grasp the enemy with an open hand gripping hard enough to cause great pain. Snake shot is a type of lead shot, it is very small, fits typically into a cartridge, and is generally used to shoot at snakes, rodents, and other small animals at very close range.


 * Gum-Gum Fire Salute (ゴムゴムお礼ファイア, Gomu Gomu Orei Faia): A stronger counter version of Gum-Gum Balloon, Luffy first absorbs the gunshots the way he does normally and then accurately rebounds the bullets right back at the enemy with twice the power as when they hit him. When he used this technique, Luffy put the thumb and forefinger of each hand together to form a rectangle with a crosshair similar to Chopper's Scope ability.


 * Gum-Gum Pinball (ゴムゴムピンボール, Gomu Gomu Pinbōru): Much like Gum-Gum Octopus Fireworks except, uffy uses both of his arms and legs to rapidly having them bouncing on the surface of an entire room to attack multiple opponents.

Gears
By taking advantage of the unique physical abilities granted by his Curséd Fruit, Luffy has invented techniques that augment his speed and strength in different ways, though each one also has corresponding physical drawbacks. He refers to these techniques as Gears.

Gear Second

 * Main article: Gear Second

Gear Second (ギア･セカンド, Gia Sekando) is where Luffy uses his legs to pump blood throughout his body at a much faster rate. Activating Gear Second also uses a lot of stored energy from his body. Leaving his body exhausted, his heart rate also increases to levels that are normally impossible. His veins are able to withstand this since they are made of rubber, thanks to the Gum-Gum Fruit. In this form, Luffy gains a considerable boost in speed and strength.

During the Enies Lobby Arc, Lucci Rob mentions that this ability is similar to steroids because his muscles are receiving enough blood to do things otherwise impossible. Lucci Rob also noted that Gear Second does damage to Luffy's own body and in turn drastically reduces his stamina and his lifespan begins to diminish due to prolonged use.

Luffy first discovers this Gear unofficially in the 7th Fairy One Piece Tail Movie, where he has a large mechanical arm falling on him, he catches it, and the impact exerts extreme force on Luffy's legs, causing him to unintentionally pump blood at an accelerated rate to perform Gear Second and use the "Gum-Gum Jet Barrel" (though he simply refers to is as a normal "Gum-Gum Double Barrel") to defeat a giant robotic battlesuit.

After the timeskip, it appears that Luffy has gained enough control over his Gear Second form, that he is able to use it in a single limb rather than his whole body. This, in conjunction with his Armament Haki, was able to take out a Pacifista with a single punch, something that took the entire Straw Hat crew to do before the timeskip. His strength in this form has also increased to the point where he could knock over a large creature like Wadatsumi with a single "Gum-Gum Jet Blast", breaking one of the giant mermen's teeth. Luffy can use Armament Haki combined with Gear Second to perform "Gum-Gum Red Hawk", which causes his fist to ignite into flames. It seems that Luffy has become far more adept with this gear as he has been using Gear Second attacks much more frequently than before the timeskip.

Techniques
The named techniques that are used by Luffy that involve this Gear are as follows:

Gear Third

 * Main article: Gear Third

Gear Third (ギア･サード, Gia Sādo) is where Luffy pumps air through his bones to make them literally gigantic. Obviously, only Luffy can do such a thing by using the Gum-Gum Fruit. Used with his already-strong physiology, this apparently gives his arm more mass and a larger area to attack with far greater force, but he sacrifices mobility for this strength, as his limbs are now so large that Luffy has extreme trouble moving unless he is in his Baloon form.

Another after effect of this is that Luffy is reduced to child-sized proportions, the duration of which is equal to the time he spent in Gear Third. Also, he is able to use both gears at the same time which he uses to defeat Moria Gecko. The Gear Third technique is first hinted at during Luffy's fight with Blueno, and first used, but not shown when Luffy is chasing Lucci Rob and Spandam, but is not seen until a later battle with Lucci Rob.

After the timeskip, Luffy's Gear Third is vastly improved upon. Previously, Gear Third would increase the size of the majority of Luffy's arm, thus reducing the speed of the attack in exchange for a powerful impact. However post-timeskip Luffy can seemingly control where the air is allowed to "sit" within his limbs, where his fist becomes large but allows a large mass to form behind the fist as the equivalent of the mass he would have achieved having his arm fully inflated. This allows a majority of Luffy's arm to remain as it is, allowing him to stretch it, thus allowing him to attack much faster than before the two-year absence.

Luffy is also shown capable of using Gear Third at the same time as Armament Haki, causing his arm to turn black and harden, with his arm in the ocean (which would normally drain a Curséd Fruit user of their power). While he is still affected by the ocean, he lands a punch which knocks an attacking Kraken out on the way to Mermen Island. Luffy is confirmed to have overcome his weakness of shrinking when deactivating this Gear, after inflating both his arms and using "Gum-Gum Wrecking Ball" on Noah for a prolonged period of time and not turning into his chibi form.
 * When Luffy reverts to his chibi form, his clothes, including his straw hat, change relative to his actual size. When Luffy moves his mass throughout his body, however, his clothes remain the same size. This appears to be the same throughout every one of Luffy's mass increases, per example his "Nightmare Luffy" form.

Techniques
The named techniques that are used by Luffy that involve this Gear are as follows:

Gear Fourth

 * Main article: Gear Fourth

Gear Fourth (ギア･フォース, Gia Fōsu) is a technique which Luffy developed during the time skip when he fought giant creatures on Rusukaina. He first coats his arm in Armament Haki and then bites into his forearm. Similar to how he activates Gear Third, he blows an incredible amount of air into his body, but this time he inflates his muscular structure.

In this form, his body's proportions become warped and is much larger in size, with his arms, upper torso, and legs coated in Armament Haki. The coating across his torso resemble the wispy ends made from flames, and he also gains shading around the inner and outer edges of his eyes.

As a side-effect he is incapable of standing still on the ground, and instead constantly bounces on the spot. His physical strength and speed are increased to the point where he is able to overwhelm Doflamingo Don Quixote, whereas beforehand both Gear Second and Gear Third were ineffective in the fight.

It also shows a versatile side of the Gum-Gum Fruit when using the elasticity to achieve a form of pseudo-flight and changing the direction of his attacks mid-strike to hit a moving opponent, strengthening his attacks in a similar manner to the Spring-Spring Fruit by compressing his arms and legs like springs. This form, much like Gear Second, seems to utilize the principles of Six Powers. It possesses both high speed movement reminiscent of Shave and the ability to kick off the air, similar to Moonwalk, creatively adapted to work even better with his body's elasticity, not just bouncing off the air but allowing punches and attacks to bounce off his own body.

According to Doflamingo, the power of his attacks increases greatly in this form. His durability is also vastly enhanced, as his body remains rubbery despite being coated in Armament Haki, as a result Doflamingo's immensely strong kicks simply bounce off of his body.

Another side-effect is its limit to how long Luffy can keep Gear Fourth active, as noted by both Luffy himself and Doflamingo. Once Gear Fourth reaches the limit, it automatically deactivates and Luffy is left exhausted, barely able to move as Haki originates from the user's inner strength or life force. He is also left unable to use Haki for ten minutes after using this technique. Even afterwards, Gear Fourth is extremely taxing on Luffy's body and stamina; after regaining his Haki from using Gear Fourth once, he barely had enough strength left to fight back, and using it briefly for a second time shortly after rendered him unconscious.

Gear Fourth uses a lot of Luffy's stamina and would cause him to burn calories a lot faster than normal. After using it while fat from eating several lifetime's supply of biscuits, Luffy started to shrink back to his normal size due to the immense calorie usage.

Techniques
The named techniques that are used by Luffy that involve this Gear are as follows:
 * Muscle Balloon (筋肉風船, Kin'niku Fūsen): By coating his arm in Armament Haki and biting into his forearm, Luffy is able to blow a large quantity of air into his body and inflate his muscular structure, with the air blown into his arm spreading out to the rest of his upper body. In this form, his durability is enhanced to the point where a Armament Haki enhanced kick from Doflamingo Don Quixote, a Warlord, bounced back harmlessly, due to his body retaining its rubber properties despite being coated in Haki.

Boundman

 * Gum-Gum Kong Burst (ゴムゴムコング, Gomu Gomu Kongu ):


 * Gum-Gum Rhino Spear (ゴムゴムリノシュ, Gomu Gomu Rino ): The Gear Fourth version of Gum-Gum Spear. After compressing both legs into his body, Luffy delivers a double flying kick. It has enough power to send the opponent crashing through dozens of buildings and across a town center. This was first used as a surprise attack against Doflamingo.


 * Gum-Gum Snake Hook (ゴムゴム, Gomu Gomu ):


 * Gum-Gum Double Snake Hook (ゴムゴム, Gomu Gomu ):


 * Gum-Gum Leo Barrel (ゴムゴム, Gomu Gomu ):


 * Gum-Gum King Kong Cannon (ゴムゴムキングコング, Gomu Gomu Kingu Kongu ):


 * Gum-Gum Rapid Kong Fire (ゴムゴム コング, Gomu Gomu ):


 * Gum-Gum Leo Rex Barrel (ゴムゴム コング, Gomu Gomu ): The Gear Fourth version of Gum-Gum Giant Double Barrel and Gum-Gum Grizzly Cannon. Before Luffy compresses his fists, like he does for Leo Bazooka, he blows a large amount of air into his arms, drastically increasing their size, then unleashes it for a devastating blow. This was first used to defeat Tesoro Gild.

Tankman: Full Version

 * Gum-Gum Cannonball (ゴムゴムキャノンボール, Gomu Gomu Kyanonbōru): After trapping an enemy within him by compressing and withdrawing his stomach, Luffy launches them forward and into the air with incredible power and speed. This technique was first used to defeat Cracker Charlotte, who, when launched, plowed through several of his immensely hard Biscuit Soldiers and was sent flying far away.

Haki

 * Main article: Haki

Shortly before the two year time skip, Luffy had awakened the ability known as "Haki" and is one of the few known people able to use all three types. Luffy was identified to possess this mysterious ability by Blackbeard after their first encounter in Jaya. He first showed the ability to use it when he knocked out Duval's steed, Motobaro, without actually hitting him. Since then, he showed increased but irregular usage of it, with very little to no control, as the series went on. It was only after the Battle of Navyford, when he started training with Rayleigh Silvers, that he actually learned about Haki and how to control it. Though it was stated that 2 years was too short a time to learn the basics of Haki, Luffy has shown a natural affinity for it, learning it in 18 months. Since reuniting with his crew Luffy has been shown to consciously, actively, and easily use Haki in combat.

After Trace was sent away to the Navy Headquarters, Luffy decided to break out of Impel Down and head for Navyford. In the process, he ran into an intruding Blackbeard who noted that Luffy's Haki increased since last time they met (in Jaya). It could be speculated that Blackbeard already noticed Luffy's Haki possession since their first meeting. The fourth time Luffy released his Haki was at Navyford, when he saw Trace about to be executed. It was then that Trace and the Navy learned of his possession of Haki, and of the Conqueror's type to top it off. This made him even more threatening to the government, although he was already threatening enough without it.

After the Navyford War, Luffy decided to train with Rayleigh. Luffy managed to learn the basics of Haki within a year and a half, even though Rayleigh had intended to spend the entire two years teaching him, meaning that he was either a fast learner once he understood the concept, or he has an innate affinity for Haki. Rayleigh departed after a year and a half, leaving Luffy to train by himself for the remaining six months. It should be noted that Luffy possesses what is considered to be a large amount of Haki.

Conqueror's Haki
Luffy is able to use Conqueror's Haki, a type of Haki possessed only by one in a million people. Luffy used this ability several times in the series, as it was the type of Haki that manifested the earliest.

The first time Luffy was identified to have possessed this type of Haki was when he stopped Sandersonia Boa from smashing a petrified Margaret, although he first showed possession of this type of Haki when he scared off Duval's bison steed, Motobaro.

When he protected Bentham from being attacked by wolves back at Impel Down (Level 5) Luffy released his Haki unconsciously. During the war at Navyford, he also used another burst of Conqueror's Haki when he saw Trace about to be executed, which knocked out a lot of individuals, both Navy and Pirates. This made it clear that Luffy, setting aside his identity as the famed pirate Dragon's son, is also a serious threat as a pirate just by possessing Conqueror's Haki.

Before training under Rayleigh, Luffy displayed limited to no control over this ability, and did not seem to realize he had it, but used it on instinct whenever it seemed to be most needed, and could still use it even when extremely injured.

With this training, Luffy has demonstrated the ability to focus his Conqueror's Haki, knocking out a small group with a quick glare without affecting anyone else. A possibility of Luffy's Conqueror's Haki is that he can tame large animals as he was capable of taming all the animals of Rusukaina Island, and tame the Kraken, which he did with great success in a very short time. Up until the fight with the New Mermen Pirates, Luffy has only used Conqueror's Haki when he needs to get people out of the way with minimum damage. The true extent of Luffy's Haki is seen when he knocks out 50,000 of Hordy Jones' men. During his fight with Chinjao during the Corrida Colosseum tournament, the two unleashed a powerful wave of Conqueror's Haki when they clashed fists. This Haki has become Luffy's specialty.

Observation Haki
Since training with Rayleigh Silvers, Luffy appears to have gained significant proficiency in Observation Haki, allowing him to tell what an opponent intends to do. He was able to effortlessly dodge a bullet shot at point-blank range by Black as well as several laser projectiles fired by a Pacifista, commenting that the last attack was "slow". His proficiency with this skill is truly shown when he was able to completely avoid Hordy Jones' Shark Arrows without effort. Luffy also displayed being able to discern Caribou's presence within the Ryugu Palace, even asking if Zolo and Sanji can sense it too. At Punk Hazard, he was able to sense the Yeti Cool Brothers attacking Chopper and Nami. He was able to sense that Rebecca had no true killing intention towards him even when she was attacking him. During the Corrida Colosseum Block C battle royale, he was able to successfully dodge all the weapons Jean Ango threw at him. He can also use the ability to measure the strength of an individual as seen when he complimented Duke Dogstorm's superior strength at a glance.

Armament Haki
Luffy seems to have also mastered Armament Haki to an extremely high extent, which has been shown to darken his body (or parts of it) and harden it. This is first shown being used when he easily defeated a Pacifista with a single Haki imbued punch used in conjunction with his Gear Second. He is also able to use his Gear Third in conjunction with his Armament Haki, being capable of knocking out a giant beast such as the Kraken easily, despite the great disadvantage of being under water (where his power was considerably weaker).

Another demonstration of Luffy's Armament Haki is during his fight with Hordy Jones, where he was able to harden his arm, leg, and forehead for both strong offensive and defensive measures. The defense of his Armament Haki, however, is not absolute; while it is good for reinforcing his near immunity against blunt attacks, it is not strong enough to defend against sharp objects, such as swords, Hordy Jones' shark teeth or Doflamingo's strings, if enough force is applied to the strike. Regardless, a small amount of Luffy's Haki used on his forehead was strong enough to shatter Rebecca's sword on impact when she was forced by Doflamingo to attack Viola.

After the air bubble was produced and merged with Noah, Luffy used Armament Haki combined with Gear Second to perform "Gum-Gum Red Hawk", which causes his fist to ignite into flames and create an explosion after it hits the target.

Luffy was later seen being able to knock back a Logia user like Caribou at considerable distance, something he was never able to do before the timeskip, without exploiting the Logia Fruit's weakness. He was also able to grab Chaser's arm in its smoke state as if it was solid, and was also able to grab and punch Caesar Clown in his partial Logia state.

Techniques

 * Armament: Hardening (武装色 硬化, Busō-shoku: Kōka): Luffy uses Armament Haki to harden his body (or parts of it). It was used for the first time against the Kraken in conjunction with Gear Third to harden his enlarged arm to the point of it attaining a completely dark and shiny appearance, in order to use his "Gum-Gum Wrecking Ball".


 * Head: Hardening (頭 硬化, Atama: Kōka): Luffy imbues his forehead with Armament Haki to harden it. This is first used in preparation for a "Gum-Gum Bell" against the Iron Shell Squadron.


 * Gear Second: Hardening (ギア・セカンド 硬化, Gia Sekando Kōka): Luffy imbues his fist with Armament Haki while under the effect of Gear Second to harden it, which also seems to have the added effect of igniting it. It was first used in preparation for "Gum-Gum Red Hawk" against Hordy Jones.

Miscellaneous Skills
He is heavily susceptible to any form of hypnotism and does not have the sense to turn away, such as Django's powers of hypnosis or Ms. April Fools Day's Colors Trap. He is also easily distracted when he sees something that's "just too cool", like seeing Chopper's transformations for the first time, the Sunny Thousand's Gaon Cannon, an energy beam from a Pacifista, his wax armor made from Mr.3's Wax-Wax Fruit powers, or the Iron Pirate "Franky Shogun", ignoring everything around him.

Luffy also has the mysterious and uncanny ability to, while completely asleep, eat as if he were awake, and even knows when more food has been placed on the table.