Originally Posted by "chaosof99 - AnimePulse"
1) Imperfect characters: All the characters have some sort of flaw in their character. Nobody behaves perfectly and sometimes there is tension between the crew. Most notable example in this regard is the moment Usopp left the crew and his fight with Luffy.
Counter-Example: Ichigo in Bleach is practically always perfect and never does anything bad.
2) The main characters can lose. Yes, technically they can't since they will not die and they will get back up to fight again, but unlike many other series, the main characters will lose sometimes and will draw a lesson out of the loss. Examples for this would be Zorro losing to Mihawk, Luffy losing to Crocodile twice and most recently Luffy losing to Magellan in their first encounter.
Counter-Example: Captain Tsubasa is pretty horrible in this regard as the team can absolutely not lose. There is always some sort off miraculous upset happening. I also heard that Fist of the North Star is also very much just Kenshiro steamrolling through legions of people.
3) Limited Power-creep: The devil fruits introduced is just a genius idea because it does not allow for other characters to learn the same fighting techniques and every characters fighting style is unique. This is even true for characters that do not use Devil Fruits.
Counter-Example: Dragonball is the most easy to pinpoint here. Oh, Goku learned how to fly, next arc everybody can fly. Goku learned how to feel auras, next arc everybody can feel auras. Goku has become as Super-Sayajin which of course can only be reached by one Sayajin every 1000 years, in the following arcs every Sayajin reaches SSJ-level...
4) Limited Deus-Ex-Machina: The problem with Deus Ex Machina is not that it is used in general. Sometimes DEM is needed to make things interesting, to surprise the reader and to show off new things. However, if the Deus Ex Machina is overused or oversteps the boundaries of previously established restrictions are overstepped. In One Piece, while there is room for new surprises, Oda does not overstep the boundaries and just lets things happen for no reason, but adheres to the previously established limitations. Examples for this would be Luffy's Gears 2 and 3 and Robin's Cien Fleur Wing where the characters use their changed properties thoroughly but still do feasible things with them.
Counter-Example: Both Bleach and Naruto are pretty bad with this. In Bleach there are almost in every single battle something happening for no reason at all, the latest being Ichigo's hole turning him into a full hollow. In Naruto the most major one was Kankuro, Temari and Gaara showing up from absolutely nowhere for no reason to save Kiba, Shikamaru and Lee. Even Lee was a pretty week Deus Ex Machina appearance in the first place as was his opponent Kimimaru.
5) Foreshadowing: Oda actually likes to do some foreshadowing and leaving the reader questioning what the significance of or the mechanic behind certain incidents was. Most notably was Robin stealing Luffy's hat during their first encounter at Whiskey Peak foreshadowing her Devil Fruit and Robin's disappearance together with the CP9 member in the dead-end street in Water 7 almost right before Sanji's eyes which foreshadowed Blueno's Doa Doa no Mi.
6) Tying up loose ends and re-using old characters: While there may be significant time in between their appearance, Oda has actually made a good habit out of re-using old characters for some purposes, such as Hatchi, Buggy and the Baroque Works recently, and giving more significance to old incidents in the plot or just tying up loose ends. The most major of this in my opinion is the reuse of Fishmen Karate for Jimbei and the crew encountering Brook and his role with Laboon.
7) Change of scenery: A very long running series like One Piece can sometimes become bland and boring as nothing really happens and almost every thing stays constantly the same. However, Oda does something great to avert this with traveling over the sea. Every single locale of One Piece has a rather unique feeling to it and is very coherent in itself. This can be observed in the landscape, architecture and clothing of the inhabitants of each island just as well as their culture.
8 ) Parallel story development: The problem with shonen fighting manga is often that while there is some overarching plot that is supposed to be achieved, the actual fights do nothing to advance the plot. In One Piece however, Oda uses the remaining characters that are not actively participating in the fights to advance the plot during the same chapters.
Counter-Example: Bleach is pretty notorious for having all other characters stand around and watch while the main characters are fighting. Dragonball also has this questionable honor.
9) Overarching and Sideplots: A lot of series have one problem: The main characters are too important. Due to the main characters being very powerful it appears as if the universe of discourse would be completely stagnant without them. They are made a root cause and main driving force for absolutely everything that happens. And if they are not, they are usually a direct observant of the other dealings.
In contrast to that, One Piece has an overarching plot which is told to the reader, even though with limits to it, about other Events throughout the world, such as Ace hunting Blackbeard, Buggy and Smoker chasing after Luffy, the World Government deciding about a new Shichibukai or the meeting between Shanks and Whitebeard. There are also sideplots told in the chapter title pages featuring previously introduced characters and adventures they have. Of course, these plots may have later significance or affect the main story but the Straw Hat Crew does neither influence nor observe them directly.