While traveling, the Straw Hat Pirates have mostly visited islands in a linear pattern, just following the route the 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 Alabasta), 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.
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 Alabasta 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.
Because the series focus on the Straw Hat Pirates, they were responsible for many actions throughout the 700+ 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.
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 Arlong 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 gained their first bounty.
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.
Alabasta: Saved Alabasta 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, and gave them a new set of 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 attacked some of the Straw Hats and took Nami. So Luffy, who did not want anyone hurting his friends, decided to fight Enel.
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. Luffy, Zoro, Nami and Chopper wanting to know why Robin had done this, invaded the HQ that was under attack by CP9 and saved Iceburg and Paulie. Usopp and Nico Robin temporarily left the crew.
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, Franky, as well, not to mention reobtaining their sniper (who temporarily quit the crew) and archaeologist (whom the crew rescued after she was black-mailed). They also encounter the legendary Marine, and Luffy's grandfather, Vice-Admiral Monkey D. Garp, as well as Coby and Helmeppo, and successfully escape from them. The crew also earned a new set of bounties, for their actions in Enies Lobby.
Enies Lobby: Raided Enies Lobby to save Robin and Franky, declared war on the World Government as a means to convice 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 are now 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 this, all Straw Hats members will have bounty.
Thriller Bark: Defeated Gekko Moriah and freed all the shadows he stole from many people. This was because the old man begged them to help while Luffy, Franky, Robin, Zoro and Sanji were originally searching for Usopp, Chopper and Nami, because Luffy wanted Brook to join and to retrieve Luffy's, Zoro's, Sanji's and Robin's stolen shadows. The ninth crew member joined the Straw Hat Pirates, the musician, Brook.
Sabaody Archipelago: Saved Keimi and Pappug 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 Fishman Island and Keimi, who has the information, found out Hatchan was in trouble. Originally, they did not want to save Hatchan but changed their minds because Luffy wanted takoyaki and Nami had already promised Keimi.
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 Keimi from being sold into slavery and Hatchan was shot by Charloss, which angered Luffy since he considered Hatchan as a friend.
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 has 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 Impel Down and created a massive breakout that brought disgrace to Impel Down.
Marineford: Invaded Marineford and got involved in the Whitebeard War, succeeded in releasing Ace but failed to save his life (or rather Ace saved him from being killed by Akainu), falling into a mental collapse.
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 seperated 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 Barujimoa 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 Barujimoa". 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 Barujimoa".
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.
Reunion to Sabaody Archipelago: The Straw Hat Pirates reunite on Saboady Archipelago, and despite the Marines sending two prototype Pacifista's, which were destroyed by the Monster Trio, and all possible armed forces, who were delayed by the Staw Hats allies, submerge to Fishman Island.
After going below the ocean's surface, Luffy, Zoro and Sanji succesfully tamed a kraken and used it to guide them towards Fishman Island. The kraken already belonged to the New Fishman Pirates and the Straw Hats were unsuccessfully intimidated by them.
After Jinbe allies himself with the Straw Hat Pirates, they manage to save the Ryugu kingdom, the Neptune family and the island from the threat of Vander Decken IX and the New Fishman Pirates, and were thus absolved of their previous crimes. Invited Jinbe to join their crew, but were turned down, saying that he wishes to first finish whatever remaining buisness he has on the island before joining them.
Luffy declares war on the YonkoBig Mom over control of Fishman Island.
They manage to kidnap Caesar Clown and, by doing so, blackmailed Donquixote Doflamingo into resigning from his position as Shichibukai and renounce his title as king of Dressrosa. However, this turns out to be a ploy by Donquixote, who used his family connections to fake the news.
Clockwork Island: Recovered their stolen ship from the Trump Siblings, effectively defeating the pirates, freeing the citizens of the island from their dictatorship, while destroying the island in the proccess
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.
Mecha Island: Helped discovered the secret of Mecha Island (that it was actually a giant turtle), saving it from the clutches of Ratchet and found the island's secret treasure, the Golden Crown.
Merveille: Fought and defeated Shiki, freeing the village he had taken over, saving East Blue, and rescuing Nami who had been kidnapped.
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.
Secon Island: The second Endpoint, the Straw Hats again faced the Neo Marines, but failed to stop them.
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.