Devil Fruit

Devil Fruit,(悪魔の実, Akuma no Mi), called Curséd Fruit (Pronounced with two syllables) in the English dub, are mystical fruit that can give the eater many kinds of strange and interesting abilities depending on the fruit and its type. There are some seen only in the Anime or only in the Manga.

About
Devil Fruit are said to be the fruit of the Sea Devil and that the secret to their power is hidden in the Grand Line. Because encounters with them are rare (especially outside the Grand Line) a number of rumors about them have risen making it difficult to tell whether some things are fact or fiction. The average person knows nothing or very little about what they are. Because of their power, if sold they can expect to reach well over 100,000,000 and Devil Fruit users themselves are sold at market prices as slaves. There are more than 100 types of Devil Fruit.

One running theme with devil fruits however, is the fact that they taste unimaginably horrible, to the point of making it seem like the eater had taken poison. The Devil Fruit, when consumed, gives the consumer a power or special trait. They come in different shapes, colors, and all Devil Fruits have swirl marks on them of some kind. There can be only one of each type of fruit. Only one bite is needed for the user to gain the power of a Devil Fruit, after which the Devil Fruit becomes a simple, useless, disgusting fruit. Swallowing the fruit whole, as Buggy did, has the same effect, peeling of the skin and eating it piece by piece also works.

Identification
There is a book in the Grand Line with Devil Fruits listed (although sometimes a Devil Fruit is said to had been unidentified). The most notable example is Blackbeard in his search for the Yami Yami no Mi. Catalogs and a book were also mentioned by Spandam and Sanji. Shanks and his crew already knew Luffy's Devil Fruit was the Gomu Gomu no Mi (Gum Gum Fruit in English versions) before he consumed it. While it hadn't been yet explained how to acquire that knowledge, according to Oda in a SBS, the same power of a Devil Fruit can exist more than one time (but not at the same time). Spandam mentions briefly that Devil Fruits have an aura around them which can often help identify them and that the two Devil Fruits he supplied to Kaku and Kalifa contained an unknown aura.

Side Effects of Devil Fruits
With this new power comes a weakness: the sea rejects the new Devil Fruit user and they become helpless while submerged in water (or "becomes a hammer," in Japanese parlance). Oda stated in SBS that Devil Fruit users are susceptible to all types of water, not just seawater. He elaborated on this, saying that "moving" water, like rain or waves, does not weaken Devil Fruit users, while standing water does. Devil Fruit powers can be canceled by Seastone.

If a user is not completely submerged, they can still use their powers from the parts of their body that are above the water. This was demonstrated by Kalifa, who was still able to produce bubbles from the parts of her body that were not under her bath water (although, as stated by Nami, this had effectively cut her strength in half while in the water). However, if the user's body has been permanently altered by the fruit, then the user's ability can be manipulated by outside sources; i.e., when Luffy was knocked into the pool at Arlong Park, other people dove underwater and stretched his neck so his head would be above water. Being weak against the sea proves deadly to many Devil Fruit users who are pirates sailing the Grand Line.

One rumor, as recounted by Cipher Pol's Jyabura, is that Devil Fruits house actual devils that will fight when placed in proximity of one another. The resulting battle would destroy the users' bodies. Nevertheless, Blueno contradicted this claim, stating that Grand Line scientists have noted that the phenomenon of one's body destroying itself only occurs when one consumes two Devil Fruits.

Research
Doctor Vegapunk, a Navy Scientist, is responsible for the research into the effects of Devil Fruit and seastone heavily. His research has also led him to devise the method that lets an object (such as a gun or a sword) gain the effect of a Devil Fruit.

Types of Devil Fruit

 * Paramecia
 * Zoan
 * Logia

Trivia

 * Devil fruit as expected, has been the center of several myths within the fandom due to fan Speculations.
 * In the original two pilots of One Piece, Luffy's Devil Fruit power, the Gomu Gomu no Mi, was the power of the Gomu Gomu tree that grew once every 50 years and there were no signs there existed other powers.
 * Many of the fruit names come from Japanese onomatopoeia and Japanese vocabulary.