While traveling, the Straw Hat Pirates have mostly just followed the route that their Log set out for them; the crew would travel from one island to another in order without backtracking or getting scattered by certain situations or forced to go off course—unless someone is taken away, the crew's visiting the island delays their voyage (i.e. partying on Conomi Islands or the national celebration in Arabasta), or leaving the Grand Line. It is not until Water 7 that things begin to shift from this 'formula'; the crew had to leave Water 7 to Enies Lobby to rescue Robin.
However, by Chapter 514, One Piece took a different twist, shattering their formulaic procession seen thus far; the entire Straw Hat crew was scattered, to 9 different islands (12 due to Luffy going to Impel Down, Marineford, and Rusukaina). Since entering the Grand Line, no Straw Hat Pirate had left the Grand Line. However, after the events at Sabaody, Chopper was sent to the South Blue, Robin was sent to the East Blue, and the rest of the crew was scattered along the Grand Line, on different Log Pose routes and far enough apart that they could not reunite easily or by normal travel means (if traveling on the Grand Line could be called normal, that is). Most of the islands the crew visited were in one season and had one climate (i.e. spring or summer; perpetual snowing, canals, or being made of clouds) when examined in the order they were visited in, like Drum being snowy or Arabasta being sandy. Until now, the story has only used an island's specific theme one time and moved on to introduce the next one; this is no more, since Nami was sent to the sky island Weatheria, Franky was sent to another Winter island (despite having the mechanical theme of Karakuri from the seventh One Piece movie), and Luffy was sent to another jungle-themed island—Amazon Lily.
After entering the New World from Fish-Man Island, the Straw Hats have not visited any islands that the Log Pose has set out. They randomly discovered Punk Hazard, an island which cannot be logged, and upon forming an alliance with Trafalgar Law, they used his navigation to get to Dressrosa, and later a Vivre Card to reach Zou. The crew has also experienced two separations since entering the New World. The first occurred in Dressrosa, when the "Curly Hat Pirates" (Sanji, Nami, Chopper and Brook) left early for Zou (with Nami, Chopper and Brook never even setting foot on Dressrosa itself). The second occurred in Zou, when the "Sanji retrieval team" (Luffy, Nami, Chopper, Brook, along with the minks Pekoms, Pedro and Carrot) headed to Totto Land, leaving the rest of the crew to head to Wano.
Because the series focus on the Straw Hat Pirates, they were responsible for many actions throughout the 900+ chapters of their adventures. These actions can be considered either a blessing or curse depending on whose point-of-view it is taken from.
Though the Straw Hat Pirates are an inner-circle group and do not care about worldly affairs, they often become involved in many peoples' wars, usually bigger than themselves, because they befriended the people involved. Most of these are people with a great amount of political power and authority behind them in some form. Their actions are often reported differently by the newspapers or the full details left unknown.
All actions done by the Straw Hats were done by either one member or the entire crew.
Shells Town: Freed Shells Town by defeating Morgan, this was due to Luffy saving Zoro and Koby. The first crew member, besides Luffy, joined the Straw Hat Pirates, the swordsman, Roronoa Zoro.
Organ Islands: Freed Orange Town by defeating the Buggy Pirates. This was done because Buggy was bothering Luffy, Zoro, and Nami. The second crew member joined the Straw Hat Pirates, the navigator, Nami.
Gecko Islands: Stopped Kuro's plans of killing Kaya and inheriting her fortune. This was because they were doing Usopp a favor. The third crew member joined the Straw Hat Pirates, the sniper, Usopp. They also gained their first ship, the Going Merry.
Baratie: Involved in defending the Baratie, Luffy only wanted to help Sanji and to free himself from being a Baratie choreboy by defeating Krieg. The fourth crew member joined the Straw Hat Pirates, the cook, Sanji.
Conomi Islands: Defeated the Arlong Pirates so they would have Nami back and ended up freeing Conomi Islands. The Straw Hats also regained their navigator, who left them in the previous arc, and Luffy gained his first bounty thus granting the crew credence as a legitimate threat.
Drum Island: Defeated Wapol and saved Drum Kingdom. This was because Nami was sick and needed a doctor. The fifth crew member (six members, counting Luffy) joined the Straw Hat Pirates, the doctor, Tony Tony Chopper.
Arabasta: Saved Arabasta and defeated Crocodile. This was because Vivi was their friend and they decided to help her. This also caused the World Government (and the world itself) to fully take notice of the Straw Hats, with Luffy and Zoro receiving new bounties. The sixth crew member joined the Straw Hat Pirates, the archaeologist, Nico Robin.
Skypiea: Were involved in stopping a 400 year old war and defeated Enel. This was because they were searching for gold and Enel's forces started direct conflict with them, such as Enel's kidnapping of Nami.
Water 7: Were caught in a crossfire between CP9 and the Galley-La. Iceburg was shot by Robin and all Straw Hat Pirates (except Usopp) were to blame. Wanting to know why Robin had done this, Luffy, Zoro, Nami, and Chopper invaded the headquarters that was under attack by CP9 and saved Iceburg and Paulie. Usopp and Nico Robin temporarily left the crew.
Enies Lobby: Raided Enies Lobby to save Robin and Franky, declared war on the World Government as a means to convince Robin to come back, and defeated CP9. The destruction of Enies Lobby was Spandam's fault (he triggered the Buster Call by mistake). As a result, CP9 became scapegoats, the blueprints were burned, which destroyed the World Government's attempt to raise an ancient weapon to end the pirate age, and they needed Robin so they can get her to tell them where the ancient weapon is, but failed to retrieve her.
After Enies Lobby Incident: After losing their first ship, the Going Merry, due to damage it took, the Straw Hat Pirates get a new one, the Thousand Sunny, and a shipwright, the cyborg Franky, not to mention reobtaining their sniper (who temporarily quit the crew) and archaeologist (whom the crew rescued after she was black-mailed). They also encountered the legendary Marine and Luffy's grandfather, Vice-Admiral Monkey D. Garp, as well as Koby and Helmeppo, and successfully escaped from them. The entire crew also earned a new set of bounties for their actions at Enies Lobby.
Thriller Bark Saga
Thriller Bark: Defeated Gecko Moria and freed all the shadows he stole from numerous individuals (including some of their own). This was because an old man begged them to help while Luffy, Franky, Robin, Zoro and Sanji were originally searching for Usopp, Chopper and Nami. The eighth crew member joined the Straw Hat Pirates, the musician, Brook.
Sabaody Archipelago: Saved Camie and Pappag from the Sea King, saved Hatchan, defeated the Macro Pirates and dealt with Duval. This was because they needed information on how to get to Fish-Man Island and Camie, who has the information, found out Hatchan was in trouble. Originally, they did not want to save Hatchan (a former officer of the Arlong Pirates) but changed their minds because Luffy wanted takoyaki and Nami had already promised Camie.
Attacked a World Noble, ended up freeing the slaves in the Auction House, and sent the entire island in a panic. As a result, AdmiralKizaru arrived, the Straw Hats were scattered, and 500 pirates were captured. This was because they were trying to save Camie from being sold into slavery and Hatchan was shot by Charlos, which angered Luffy since he now considered Hatchan as a friend.
After Separation by Bartholomew Kuma
Monkey D. Luffy
Amazon Lily: Managed to prevent Hancock from killing three of her warriors (Sweet Pea, Marguerite, and Aphelandra), and covering her sister Sandersonia's back to prevent her slave mark from being exposed. Wanting to save Ace from execution, Luffy convinced Hancock (who had fallen in love with him) to comply to the World Government's demand she originally ignored to go to war against Whitebeard; by doing so, he prevented her from losing her Shichibukai title and the treaty to protect Amazon Lily that goes with it. This also saved Boa Hancock's life.
After the War: Recovered and remembered the desire to reunite with his crew thanks to Jinbe, reunited with Rayleigh on Amazon Lily.
Impel Down: Invaded the complex and created a massive breakout that brought disgrace to Impel Down.
Marineford: Invaded Marineford and got involved in the Whitebeard War, had his heritage revealed, succeeded in releasing Ace but failed to save his life (or rather Ace saved him from being killed by Akainu), and falling into a mental collapse before being evacuated from the area.
After the War: Snuck into Marineford a second time and rang the Ox Bell 16 times. This was, however, a diversion to the real message: a temporary tattoo on his arm which informed his crew to meet up in two years, not three days as was originally planned. His actions during the war earned him a new bounty
Rusukaina: Learned to control Haki in one and a half years. Became the "boss" of the island where he was training.
Kuraigana Island: He landed in Kuraigana Island, where he met up with Perona. After she tended his wounds, Perona and Zoro came to trust each other. Mihawk later returned to the island and gave Zoro a boat to leave the island after bringing the results of the war, but Zoro encountered the Humandrills. Upon finally defeating them, he returned to Mihawk and begged for an apprenticeship. Discerning that Zoro was throwing away his pride for the sake of someone else, he agreed.
Weatheria: She landed on Weatheria. After hearing about the Whitebeard War, she tried stealing the weather equipment after studying there for a while. She was caught and locked up, but was able to escape and take the stolen weather equipment and Haredas with her. After reading Luffy's message, she convinced the scientists to forgive her and decides to learn from Haredas. Later, when informed of the unusual weather of the New World by Haredas, she told him that she must learn it all to be able to help Luffy in the future. She also inquired about the weather ball, which, if used improperly, could plunge the world into chaos.
Boin Archipelago: He had gotten fat by overeating the food he found on the island. After the news came out about the death of Ace, he had gotten brave. He even risked his own life to get off Boin Archipelago. After being saved a couple of times by his protector Heracles, he had to let him know that he wants to see Luffy through his pain. After receiving Luffy's message, Usopp starts working out, deciding that he needs to lose weight, gain muscle, and grow stronger so that he did not have to stand around watching anymore, and to help Luffy out. He becomes Heracles's apprentice, and begins learning about aspects of the forest, such as the Pop Greens, which are seeds of the hostile plants of the forest that have many uses. It was when Luffy decided to remain separated for two years that Usopp declared his newest ambition, to help Luffy become the Pirate King, he himself would become the true King of Snipers.
Momoiro Island: He landed on Momoiro Island, and was chased by the okama, and converted into one temporarily. He eventually returned to normal, and met with Ivankov, who refused to give him any information on Luffy due to Sanji having trouble giving evidence that he is a Straw Hat Pirate from the poorly drawn Wanted Poster. However, he did receive a newspaper on how Luffy was doing. Later, Sanji accepts a challenge to obtain the 99 recipes of Attack Cuisine by defeating the 99 Newkama Kenpo Masters while simultaneously trying to prevent himself from turning into a Okama. He succeeds and managed to get a ride back to Sabaody Archipelago afterwards.
Tony Tony Chopper
Torino Kingdom: When he landed in Torino Kingdom, he fell in the war between the gigantic birds and natives. Chopper communicated in a way with the natives and birds and explained to the feathered beasts that the natives do not want to eat their eggs or steal their treasures, just the plants near their nests. Chopper bravely flew off to Sabaody. After receiving Luffy's message, he returned back to Torino Kingdom, with the intent of growing stronger and developing new medicines by studying the plants there.
Tequila Wolf: She landed on Tequila Wolf, where she was forced to help build a bridge on the orders of the World Nobles since 700 years ago. She tried to escape from the handcuffs until she was eventually freed by the Revolutionaries.
Baltigo: After reading Luffy's message agreed to be brought to Dragon in hopes of becoming stronger, which is the first time she thought of becoming stronger for others.
Karakuri Island: He landed on the future land Baldimore on Karakuri Island. After hearing about the Whitebeard War, he breaks into Dr. Vegapunk's lab to find an icebreaker ship. While pursued by Marines, he pressed the self-destruct button in Dr. Vegapunk's old home, which was known as a historical treasure. This event would later be known as the "Nightmare of Baldimore". Franky got his skin blown off his face, but managed to escape from the Marines. He ended up in a second secret laboratory which the entrance to was exposed by the explosion of the first, and becomes interested in the schematics of various weapons and other advanced technology of Vegapunk. He decides to live there, and also dons a tiger rug to hide and disguise his hideous face. However, the rug caught on fire, and Franky ran outside just as the Marines had caught up to him, scaring them all with his flaming, bestial appearance. This incident would later be known as the "Legend of the Sacred Burning Beast of Baldimore".
Namakura Island: He landed on Namakura Island during the middle of a devil-summoning ceremony. He wrote a song to raise the cultists' spirits and helped them fight against and capture the Longarm Tribe. After releasing them, the Longarms kidnapped him since people would pay a lot of money to see a living skeleton.
Teena Geena Kingdom: He was held on display in the Teena Geena Kingdom, where he tried to adjust his leaning pose against the wall from 45 degrees to 40, but it failed. He decided he needed to try something else to grow stronger for Luffy, and released his new single, "Bone to be Wild".
He has since become a major rock star, going on a world tour which ended in Sabaody Archipelago.
Fish-Man Island: Intervened in a coup 'd'état staged by the New Fish-Man Pirates and the Flying Pirates, defeating them and saving the Neptune Royal Family and the island. Later, having befriended the citizens of Fish-Man Island, Luffy declared war on Big Mom and her crew for ownership of Fish-Man Island. They attempted to recruit Jinbe, who refused, saying that he has some business to take care of before he is able to join them.
Punk Hazard: After answering a distress signal, the Straw Hats land on Punk Hazard, an island which can't be 'logged'. There they learn of the mad scientistCaesar Clown, who not only conducted inhumane research on children and his own subordinates, but created chemical weapons of mass destruction, as well as making a vital chemical for an important product. After making an alliance with the new Shichibukai, Trafalgar Law (in order to defeat the emperor, Kaido), as well as the samurai from Wano Country, Kin'emon, and his "son" Momonosuke, together with Vice AdmiralSmoker and his G-5 Marines, they defeat and capture the Caesar. With the destruction of the SAD factory, the Straw Hats learn of the second stage of the plan to challenge the emperor: blackmailing the man who supports Caesar, Donquixote Doflamingo, by holding the scientist for ransom.
Dressrosa: Upon arriving on the island with the intent of destroying the SMILE Factory which produces Artificial Devil Fruits for Kaido, as accordance with their alliance with Law, things quickly go awry. Doflamingo counters there initial plans using unprecedented planning, influence and power, which caused some of the other Straw Hats, along with Momonosuke and Caesar, to flee to Zou with the Big Mom Pirates on their heels. However, the Straw Hats on Dressrosa unintentionally made several new allies which included the local dwarftribe, a rogue toy, members of the ex-Royal Family as well as a small cell of revolutionaries, with one of them revealing a personal connection to Luffy. Together, they unveiled Doflamingo's evil conspiracy and destroyed the factory, making the Shichibukai desperate enough to attempt to destroy the country in order to hide his secrets. Luffy defeats Doflamingo and saves Dressrosa. Unlike in Arabasta, the ordeal is not covered up by the World Government thanks to Issho. Because of Doflamingo's defeat, all his customers and buyers receive negative impacts, with some of them directing their grudge on the Straw Hat-Heart Pirates Alliance. Finally, seven individual groups who admire, or feel indebted to, the Straw Hats join in an alliance under Luffy, to form the Straw Hat Grand Fleet.
Four Emperors Saga
Zou: The group that left to Zou before their captain is revealed to have saved the country from a pirate named Jack, an officer of the Beasts Pirates. Nearly two weeks later the rest of the crew arrived, reuniting Law with his crew and intent on finding the samurai's last companion, the ninja Raizo. However, for some reason, Sanji had separated from the rest of the crew. After learning the truth about their samurai friends, as well as their connection to the Mink Tribe, the pirates form an alliance with the warriors of Wano and Zou to defeat Kaido, as well as the traitorous Shogun of Wano.
Totto Land: The Sanji Retrieval Team, accompanied by Pekoms, arrive at territory of the EmperorBig Mom. There, they intend to rescue Sanji from the political entanglements set into motion by a new alliance between Sanji's family and the Charlotte Family. They first make landfall in Cacao Island, where they encounter Sanji's arranged fiancee. Following a route she recommends, they eventually arrive at Big Mom's base of operations, Whole Cake Island; there, they split into two teams, each with a separate mission: Brook and Pedro travel to Sweet City, in pursuit of Big Mom's Road Poneglyph, while Luffy, Nami, Chopper and Carrot enter the mysterious Seducing Woods. Eventually, everyone (including Sanji) converged in Big Mom's residence, Whole Cake Chateau. They allied with the Fire Tank Pirates to assassinate Big Mom and save the Vinsmoke Family, who were deceived by Big Mom. They succeeded in liberating the Vinsmokes but the assassination plan failed. However, the crews were saved when the Chateau collapsed, allowing them to escape. They later joined forces with Pudding to make a secondary wedding cake to stop Big Mom's rampage. While Luffy was engage in battle against Katakuri, Sanji, Pudding, and Chiffon baked the cake, and the rest of the Sanji Retrieval Team lured Big Mom to Cacao Island. After Luffy defeated Katakuri, he was saved by Sanji and Germa 66 before they made it back to the Sunny where they were pursued by Charlotte Smoothie's fleet. The tenth crew member, their helmsman Jinbe, also officially joined but had to stay behind to protect his former crew.
Mirro-World: Taking Charlotte Brûlée as a hostage, the Straw Hats gain access to this realm and used it as a key element in their and the Fire tank Pirates assassination attempt against Big Mom. Later, Luffy duels Charlotte Katakuri in this realm, and barely wins.
Germa Kingdom: As the Sanji retrieval team make their way through Totto Land, Sanji himself returns to his home country, which has begun converging at Whole Cake Island in preparation for his wedding. The Big Mom Pirates later attempt to forcibly take over the kingdom, but the Vinsmoke's later arrived and defeated the pirates, before having the kingdom assist the Straw Hats escape from Totto Land, in order to repay their debt.
Wano Country: While the Sanji Retrieval Team journeyed to Totto Land, the rest of the crew went to Wano Country with the Heart Pirates and the Kozuki Family retainers. There, they infiltrated the Flower Capital by creating aliases for themselves and taking various professions, as a way to gather information while waiting for their crewmates to arrive and the alliance to make their move. However, before all the Straw Hats could reunite, Luffy faced Kaido in single battle and lost, getting himself imprisoned by the enemy. Fortunately, those obstacles did not prevent the Straw Hats from continuing to recruit allies for the upcoming battle, including former daimyo Yasuie, yakuza bosses like Hyogoro, the prisoners of Udon's Prisoner Mine and the remaining members of the Nine Red Scabbards and their subordinates. On the night of the Fire Festival, the Straw Hats, together with their alliance and the Kid Pirates set sail to Onigashima, where the Beasts Pirates base resides. On the way, Jinbe joined them, officially joining the Straw Hats as their helmsman. The alliance then infiltrated Kaido's castle, before launching an all-out war against the newly established Beasts and Big Mom Pirate alliance. During the battle, the Straw Hats gained new allies in Kaido's "son", Yamato, and the former Tobi Roppo, X Drake.
Hannabal: Participated in the Dead End Race, and though they were the only surviving crew at the end of the race, since they did not reach the finishing island, at Partia, they did not win. They also defeated the Gasparde Pirates. (Dead End Adventure)
Dock Island: The Straw Hats unofficial base while they combatted the Neo Marines, they also gained equipment in order to combat the enemy for their final confrontation on Piriodo. (One Piece Film: Z)
Secon Island: The second Endpoint, the Straw Hats again faced the Neo Marines, but failed to stop them. (One Piece Film: Z)
Piriodo: The final Endpoint, the Straw Hats fought and defeated Z, leader of the Neo Marines, preventing him from destroying the island, and thus the entire New World. This was originally because Z's subordinate, Ain, had rejuvenated several of the Straw Hats, and Z himself had stolen Luffy's straw hat. (One Piece Film: Z)