A standard Poké Ball.
A Poké Ball (モンスターボール Monster Ball) is a small, spherical device used by Pokémon Trainers to "catch" and store Pokémon in the fictional video game series Pokémon. Many variaties of Poké Balls exist; the regular Poké Ball which is simply called a Poké Ball, The Great Ball, the Ultra Ball, the Master Ball, the Safari Ball, the Park Ball, and many other types of specialized Poké Balls designed by Kurt.
A regular Poké Ball features a red top, white bottom, and a black ring going through the center horizontally. In the middle of the Poké Ball, a there is a small, silver button which can be pushed to release or call back a Pokémon. The Poké Ball is designed to be portable. In the Pokémon games, it is not possible to carry a Pokémon which is not in its Poké Ball, with the exception of Pokémon Yellow, which allowed a Pikachu to follow your character.
Although the exact dimensions of the Poké Ball are not known, it's probably around 4 or 5 centimeters in diameter, although, according to the Pokémon Anime, the button on the center of the Poké Ball can also be pushed to shrink so it is small enough to attach to a belt.
Uses
Capturing Pokémon
To use a Poké Ball to "catch" a wild Pokémon, a Pokémon trainer will simply throw an unoccupied Poké Ball at the wild Pokémon. The wild Pokémon will then be absorbed into the ball, and will attempt to break free. If the Pokémon has not been weakened enough during the time of catching, it may be able to break free of the Poké Ball (only during the first few moments of its catching, while it's still struggling), which is a good reason to use a stronger Poké Ball over the regular Poké Ball, such as a Great Ball, which is 50% stronger than a regular ball. If the Pokémon does manage to break free, the Poké Ball used to attempt to catch it will break and is no longer usable. Poké Balls can not be used to catch already caught Pokémon (Pokémon belonging to other trainers). It is also programed not to catch humans. If the red beam hits something other than a pokemon, it will not capture it. However, it will burn it slightly( can be seen in the anime where a poké ball accidently shoots Jessie.)
Storing Pokémon
Once a Pokémon has been successfully caught in a Poké Ball, it will become loyal to its catcher and will usually obey them. For this reason, a Pokémon can not generally be considered "evil" — a Pokémon is only as evil as the trainer who caught it. It is not known what a Pokémon does whilst inside their Poké Ball, if they do anything at all, although it has been mentioned that the inside of a Poké Ball is "designed to be as comfortable for the Pokémon residing within", although this is not necessarily true. The Pokémon inside may simply be sleeping, or completely unaware of its own existence. Pokémon are, however aware when inside their Poké Ball — by calling their name, the Pokémon will emerge from its Poké Ball almost immediately.
Rarely even, a Pokémon will release itself from the Poké Ball. In one episode of the Pokémon animé, which should not be taken seriously, the inside of a Psyduck's Poké Ball is shown — it simply appears as an empty space consisting of mirrors and circuitry. To release or recall a Pokémon, trainers either say the Pokémon's name ("call it") or push the small button on the Poké Ball. The naming command is usually accompanied with a phrase — such as Go, Eevee or Return, Bulbasaur!. A Poké Ball can only store one Pokémon at a time. For this reason, a trainer may carry as many as six occupied Poké Balls at once — although they may carry up to 99 spare Poké Balls for catching more Pokémon. If more than six Pokémon are caught, the additional ones will be transferred to a PC.
Poké Ball Storage
Due to the Poké Balls small size, it is hard to imagine how large Pokémon, such as Wailord, or even smaller Pokémon such as Natu manage to fit inside the Poké Ball. Although this has never been made clear officially, when a Pokémon is absorbed into a Poké Ball, their form "shrinks" and turns into energy. It is possible that the Pokémon are simply stored as energy in their Poké Balls, although this, of course, arouses many other questions, such as how they can return to a tangible form.
Variants
Regular Poké Balls
Regular Poké Balls are balls which have an equal level of catching for all Pokémon. Some Pokémon are harder to catch, but all are on the same scale. All Poké Balls have a white bottom unless otherwise stated.
Poké Ball
The regular Poké Ball features a red top, white bottom, and a horizontal black ring circling the ball. This type of Poké Ball is the weakest and the only type typically available at the beginning of the Pokémon games.
Great Ball
The Great Ball has a blue top and a white bottom, as well as the horizontal black ring. It has a 50% higher chance to successfully catch a Pokémon than a regular Poké Ball.
Ultra Ball
The Ultra Ball has a 100% higher chance to catch a Pokémon than a regular Poké Ball, and a 50% higher chance than a Great Ball. It has a black and yellow top, often with the yellow forming an "H" on the top of the ball.
Master Ball
The Master Ball, the best and rarest ball available in any game. It has a two-shade purple top forming two brighter purple circles on the sides of the top, as well as the letter "M" printed on the top. The Master Ball has a 100% chance to catch any Pokémon, no matter what the circumstances and could be described best as "the ball that never fails". You can only find one of these in the video games with the exception of getting 1st place in the lottery. Will catch a Pokémon without fail.
Special Poké Balls
These are balls which are specialized for catching certain Pokémon.
Heavy Ball
The Heavy Ball, one of the many Poké Balls featured in the Gold and Silver games can catch large and heavy Pokémon such as Snorlax better then a Poké Ball. It has a dark blue top with lighter blue circles on either side at an angle from the central button, the topmost of which is the largest and the lower-most of which are tiny and almost the same shade of blue as the majority of the top.
Safari Ball
Only given to trainers in the Safari Zones in Pokémon Red, Blue, Yellow, Ruby, Sapphire, Emerald, Diamond and Pearl in exchange for all Poké Balls the trainer may be holding for as long as they are in the Safari Zone. This Poké Ball has a green and yellow striped top and carries a 50% higher chance of capturing a Pokémon in the safari zone than a standard pokeball, but can only be used in the Safari Zone.
Friend Ball
About as effective as a standard Poké Ball. However, Pokémon captured by this ball will bond more quickly to their trainers than with any other ball. This ball has a green top decorated with two red dots slanting toward the center button on both sides of the vertical mid-line on the top half and a single red dot near the "top" part of the ball's top half as seen from the front.
Lure Ball
Best used to catch Pokémon found via fishing and carries a 50% higher rate of capture than a normal Poké Ball for this purpose. It is characterized by a blue top with a red "V" going up the middle which is decorated by three vertical yellow lines.
Level Ball
Catches Pokémon of a level lower than that of the Pokémon currently in-battle. It has an orange, red, and black top with the red forming a "V" between the orange and black. Like most Poké Balls, it has a white bottom and a black band around the middle and the button.
Moon Ball
Used to catch Pokémon that can only evolve through use of the Moon Stone such as Clefairy, Jigglypuff, Nidorina, and Nidorino. It has a black and blue top, with the blue being on one side of the top and black on the other. In between the two sides of the top half on the front is a yellow crescent moon.
Timer Ball
For every ten turns that pass in a battle with a wild Pokémon, the chances of success for capturing the Pokémon increases. It's starting effectiveness is no better than that of a standard Poké Ball. It has a black, white, and orange top with the sides of the top half being range and what looks like a cooking timer handle of orange pointing toward the button.
Park Ball
Given only in the Bug Catching Contest in the Pokémon games of Gold, Silver, and Crystal. This ball is never seen on screen but is described as having a dark green top with brighter green "wings" spreading from the button out in diagonal angles on both halves similar to that of a butterfree and has two red dots on the top half above the button. It is as effective as a standard Poké Ball.
Nest Ball
The Nest Ball operates similar to the Level Ball. The lower the level of the Pokémon you face, the higher the chances of capture. It has a green top with yellow bands that wrap from the sides up around the back before ending in a circle at the top to make a design that imitates a woven nest.
Net Ball
Allow easier capture of Bug and Water Pokémon. It has a light blue top with black bands crossing it in a "net" pattern, often raised above the ball's surface. It has a 75% higher chance to capture bug and water Pokémon, otherwise it is only as useful as a normal Poké Ball.
Dive Ball
Used to catch Pokémon found on the sea floor. It is best used on or under water. The entire ball is various shades blue except for the black horizontal band around the middle, and a white "cap" on the top of the ball in which the blue forms a gentle "wave" pattern around. It has a capture rate of 75% for Pokémon seen on the sea floor.
As of Generation IV, the Dive Ball is more effective on Pokémon found while surfing. This change was due to the lack of underwater areas in the Sinnoh region.
Fast Ball
A Poké Ball exclusively in Pokémon Diamond, Pearl and Platinum version. It catches Pokémon which run away quickly and easily such as Pokémon with the Run Away ability or Legendary Pokémon like Suicune. It is characterized by yellow half-circles on the sides of both the top and bottom halves, with the top half being primarily red and carrying a lightning-bolt yellow mark on the very top.
Quick Ball
Has a higher chance of capturing a Pokémon the earlier it is used in battle. At the beginning of the battle, its catch rate is 4x. This is reduced every five turns the battle carries on, to a minimum catch rate of 1x.
Repeat Ball
Best for catching Pokémon that have already been caught before. Its distinguishing features consist of a red top similar to a normal Poké Ball, with a gold and continuing series of connected circles starting from the button and ending at the rear of the top half. The open spaces of each circle are colored black.
Love Ball
Easily catches Pokémon of the opposite gender of your active lead Pokémon. It has a pink top with a heart-shaped design near the button with a dark pink border and a light pink interior. Its success rate is about 75% to 100% for opposite gender Pokémon.
Dusk Ball
The dusk ball is exclusively for Diamond/Pearl/Platinum, a ball with normal success rate, although the chance increases if the time is dark (usually after 6 pm, or dark, to around 4 am) or in a dark area, such as a cave. It is gray and has green spots around it.
Premier Ball
The Premier Ball was created for a special event. It is entirely white except for the band around the middle which is red. According to the official Pokémon Colosseum game guide, it has the same catch rate as a regular Poké Ball, "but it looks cooler." It can be obtained by purchasing 10 Poké Ball from a shop (for Pokémon Ruby, Sapphire, FireRed, LeafGreen, Emerald, Diamond, Pearl, Platinum version only).
Cherish Ball
It is a Poké Ball only obtainable if you receive a Pokémon at a special event. It is completely red.
Luxury Ball
The fanciest ball made, and the most expensive known. It is designed for luxury as its name suggests. While its is the same as a normal Poké Ball in terms of success rates in general, a Pokémon caught in this ball will form a bond with its trainer more quickly. It is almost entirely black with a cold band around the middle as well as a gold button, and carries rings of red on both halves which themselves are flanked by rings of gold.
Other Types Of Poké Balls
These include the types of Poké Balls that have appeared in the anime, manga & games.
GS Ball
In the anime, Professor Ivy was the first character to possess the GS Ball. She called upon the help of Professor Oak to study it, but couldn't figure out how to open it or transmit it via PC. Professor Oak asked Ash to go to the Orange Archipelago and get it from Professor Ivy, which he did in Poké Ball Peril. This prompted Ash's participation in the Orange League.
At one point, Ash tried simply calling a Pokémon to be released but this did not work.
When Professor Oak couldn't do anything with it, Ash was once again asked to deliver it to Kurt, a Poké Ball researcher and manufacturer living in Johto's Azalea Town. It presumably still resides there to this day, and its purpose was, before 2008, unknown. In an interview with Masamitsu Hidaka in 2008 by the webmaster of PokéBeach, it was explained that the GS Ball was meant to contain a Celebi that was to be the star of a large arc of the Johto saga. However, it was decided that Celebi would be the star of the fourth movie, so the story arc was viewed as redundant and shelved. The ball was left with Kurt with the hopes that viewers would eventually forget about it.
People thought this gs ball stood for gold silver, hinting at remakes of the games. Nintendo are now creating a gold silver remake for DS, as announced in ONM magazine.
Mewtwo Ball (Clone Ball)
These Poké Balls look like a black and gray man with a gold strip and a ruby eye in place of the white button.These can capture other Trainer's Pokemon and even those inside their Poké Balls by capturing the actual Poké Ball as well.
Dark Ball
Only used by Lord Vicious The Iron Masked Marauder, it is black all over with a gray strip, a dark gray button and many dents all over. Any Pokemon caught with this ball become unswervingly loyal to Lord Vicious to the point there they will attack and possibly kill their friends and family. It instantly raises any Pokemon to the highest level. The Dark Ball also installs them with a sinister personality to fit. Vicious used this ball to capture Celebi with his Scizor, Sneasel and his newly stolen Tyranitar.
Old Ball
This Ball Was Created By Professor Samuel Oak and Is Not Avalible In the Games. This Ball Makes Its Appearence In "Pokemon 4ever." It is a murky brown color and is possibly a pre-modern-day pokeball. The user had to turn a small crank like those on wind-up toys just to get it to work! It was only seen sending out a pokemon, never catching.