One Piece is a series known for its meticulous world-building and the insane amount of little details that author Echiro Oda manages to pack into every scene. This has led to fans of the manga going over every panel of each chapter with a microscope, looking for things that most might have missed. When they find something, theories start flying.
Given that the series has been running for over two decades, it's inevitable that some of those theories will turn out to be right. Here are ten fan theories that turned out to be right on the money.
The Time Skip
The Whitebeard War arc shook up the status quo of the series in a massive way. One of the most powerful pirates in the series was dead, along with Luffy's brother Ace. The Marines headquarters was destroyed, the mythical treasure One Piece was confirmed to exist, and a new age of piracy was kicked off. After so many world-altering events happened in the space of one arc, fans speculated that there would be a time skip, and they were right.
After realizing that he and his crew were badly outclassed by the heavy hitters of the New World, Luffy decides to postpone the reunion of the Strawhats by two years to give them time to train and get stronger.
Gear Fourth
Luffy's Gears techniques were his biggest power up to date when they first debuted in the Enies Lobby arc. Granting an explosive increase in speed and power, the Gears allowed him to keep up with the ever-increasing strength of his opponents. For a while, only Gear Second and Gear Third were confirmed to exist, but fans were speculating that there could be further Gears down the line.
In the Dressrosa arc, this theory was proved to be correct. Backed into a corner by Doflamingo, Luffy reveals Gear Fourth, his strongest form yet. Might there be a fifth Gear in the future? Don't rule it out.
Sabo's Survival
Sabo was a childhood friend of Ace and Luffy who was presumed to be dead after a World Noble blew up his makeshift pirate ship as he sailed out to sea. Given that flashbacks are where most characters die in One Piece, it was assumed by many that the boy was dead. But there were always some in the fandom who maintained that a character is never dead unless you've seen their corpse. They were right.
It turns out Sabo survived his brush with death, gaining a wicked scar and a bad case of amnesia. He joined up with the Revolutionaries and was reunited with his adopted little brother in the Dressrosa arc.
Emperor Blackbeard
Marshall D. Teach, aka Blackbeard, has only gotten a bit of screentime here and there in the series so far, but he is one of the most important characters in the show. He was the one who caused the Whitebeard War by killing one of Whitebeards subordinates and then capturing Ace to become one of the Warlords of the Sea. He then made his biggest move to date when he showed up for the climax of the war, revealing a powerful crew plucked from Impel Down, and stealing Whitebeards Devil Fruit ability.
After all this, fans speculated that he would gain the position in the Four Emperors left empty by Whitebeard. They were correct, and Blackbeard continues to shape up to be one of the series biggest villains.
Zoro and Mihawk
Ever since he first joined the Strawhat crew, Zoro has made his intention to become the strongest swordsman in the world abundantly clear. He got a shot at taking the title from its current holder, Dracule Mihawk, early on in the series... and lost badly. But though he lost, Mihawk took an interest in Zoro and encouraged him to get stronger and challenge him again.
Mihawk's desire for a worthy opponent led some to speculate that he would train Zoro eventually. Fans were proven correct when Zoro is accepted as Mihawk's pupil right before the time skip.
The End Of The Seven Warlords
The Seven Warlords of the Sea are the privateers of the One Piece universe; seven powerful pirates who have chosen to work for the World Government in exchange for having their bounties suspended. But the Warlords have never truly been loyal to the Government. Most of them won't even bother to show up when they are called to a formal meeting. Furthermore, several of them have been revealed to have been committing heinous crimes while under the protection of the World Government.
Given how often the Warlords cause more harm than good for the World Government, many fans assumed that the system would eventually be abolished. As of recent chapters they have been proven right. The Warlords were disbanded, and their bounties have been reinstated.
Sanji's Family
Sanji has been one of the more mysterious members of the Strawhat Pirates since he first joined up early in the series. While we knew that he had been taken in by a pirate turned chef and taught to cook, most of his backstory remained shrouded in mystery.
Various hints had been dropped though, such as him using the alias Mr. Prince and briefly mentioning his homeland of the North Blue. Even more, interestingly, his wanted poster is the only ones seen thus far to have only, "Alive," instead of dead or alive.
In the Whole Cake Island arc, it is revealed that Sanji is a member of a notorious group of assassins known as Germa 66, who rule the North Blue. His real name is Sanji Vinsmoke.
Lola and Big Mom
Lola is a pirate first introduced as a prisoner on Thriller Bark during the titular Thriller Bark arc. At the end of said arc, she gave Nami a way to locate her mother in the New World, saying that she was a powerful pirate. Many fans immediately theorized that her mother was none other than Big Mom, one the Yonko, or Four Emperors.
Much, later on, it turned out that they were right. Lola is indeed the daughter of Big Mom, one of many, as the Yonko has many children so that she can force them into political marriages. Lola ran away from her mother after the pirate tried to force her to marry a man she did not love.
The Straw Hat Fleet
Luffy has been recruiting new members into the Strawhats since the beginning of the series and still does so to this day. Anytime a new supporting character is introduced, fans quickly begin to speculate on whether or not they will join the crew. This led some to believe that there would eventually be a Strawhat Fleet, similar to the ones the Yonko have.
After working together with several pirate crews during the Dressrosa arc, those crews offered to join Luffy as a fleet. Luffy rejected the idea. They did it anyway, becoming the Strawhat Grand Fleet, and proving the theorists right.
Zoro's Newest Sword
Zoro is the creator and only known user of Santoryu or the Three Sword Style. Because of this, he carries three swords at all times and has had to replace broken or lost blades more than once in the series. Given that Wano Country is the home of Samurai in One Piece, many fans theorized that he would pick up a new blade during the Wano arc.
During the arc, Zoro acquires Enma, a sword that was wielded by the former Shogun, and the only known weapon to have ever injured the Yonko Kaido. Once again, the fans were proven right.