Indian Poker

Indian Poker (インディアンポーカー) is a type of card which allows one to view the dreams of another. Originally devised by Kuriba Ryouko based on work carried out at Clone Dolly Ideal,  they have been created and spread around Academy City.

Etymology
Indian poker, or, is a poker game where the players see the cards of the other players except their own. Each player is dealt one card which is displayed to the other players, traditionally stuck to the forehead like an Indian feather, followed by betting as to whether they have the highest card based on the other player's cards and their bets.

Appearance
In the manga, Indian Poker cards are depicted as rectangular and light-colored, with a slightly darker hued strip running along the right border and two concentric arches of similar hue in the bottom-left corner.

Most of the card's front is taken up by a box with an image. Many of the seen cards have two flower-like shapes, one in the top-left and one in the bottom-right, over a dark background. Some high-ranked cards have a more shiny image.

In the anime, the card's image has several concentric circles centred on the middle.

The type of dream apparently affects the colors on the card, with orange supposedly being an enjoyable or happy dream.

Production
A dream is recorded on the card by someone who attaches a machine to themselves when they sleep. Then the person who has the card may view the same dream that was recorded on. The instructions for making the machine used to create the card was released by someone online for free. The machine is created by combining various artificial esper power toys. The type of dream input into the card will affect its color, with orange being linked to joy and happiness. To use the card, one must put it on their forehead when they sleep. The aroma elements in the card are smelled while asleep, producing signals in the person's brain and creating the dream. It is also said that the cards are good for learning by having someone of high proficiency in some subject create a card, for example learning another language or becoming skilled in a sport.

Dream Ranker
Those with the ability to create great dreams for others are known as a Dream Ranker (天賦夢路 (ドリームランカー) ). Those that can create useful cards are given ranks, with the highest being "S" or "A" rank, whose cards can sell for lots of money. A similar ranking system is also used for the cards produced.

Transactions
Normally, Indian Poker cards are exchanged between circles of friends without any monetary exchange involved. However, the demand for particular cards increases as the value of the card increases, allowing people to earn an income out of performing transactions involving Indian Poker cards. (One notable exception is the high-ranking Dream Ranker known as BLAU, who distributes his Indian Poker cards for free. ) For this reason, some people act as "traders", who mainly engage in transactions involving Indian Poker cards, notably the exchange of a single card of a particular rank for multiple low-ranked cards or the direct purchase of a card using money.

With Indian Poker cards being sold online, certain people have taken advantage of it for a con, attaching a photo of an attractive girl to a card and claiming that it is part of the dream to sell it for a high price and make a profit.

Background
The original cards which became the basis for Indian Poker were developed as part of the experiments being performed at Clone Dolly's third laboratory, Ideal. Kuriba Ryouko, the creator of Indian Poker, visited Clone Dolly several times prior to its closure. By recording and teaching an impure version of an esper's Personal Reality extracted through their dreams to alter multiple espers' powers in a desired direction, researchers hoped to guide them into creating the "ideal" power they sought, with Yuuri Senya acting as the core. Shundou Toshizou had plans to spread the cards throughout Academy City after the experiment, but they were dashed by the experiment's disastrous outcome and the subsequent shutdown of Ideal after his Board sponsor pulled out (as part of a deal with Shokuhou Misaki).

Long after the Ideal incident, following the conclusion of an experiment where she had been separated into two cyborgs for a year before being recombined, Kuriba Ryouko learnt of her mechanical doppelganger, supposedly another soul created as a side-effect of the experiment which had come to reside in the combined cyborg parts. Unable to come up with a solution to the problem with her own knowledge, she hoped that by distributing the method to create Indian Poker cards and spreading her knowledge through the cards, it would eventually mutate to produce a solution or find someone capable of achieving a breakthrough. Around the same time as Indian Poker was spreading, persons associated with Clone Dolly Ideal, moved to make use of the cards to accomplish Ideal's unachieved goal.

Dream Ranker Arc
Misaka Mikoto was introduced to Indian Poker by Hokaze Junko, who gave her a card in an attempt to apologize for causing a quarrel between her and Shokuhou Misaki, explaining it as a popular card used to peek into the dreams of someone. Seeing Mikoto's card, Saten Ruiko explained its purpose and how it was made. Using the card that night, Mikoto dreamt of a world filled with Gekota, which greatly pleased her. She frolicked with the Gekota until she was led to a castle by one of them and met the queen, who turns out to be Shokuhou. Mikoto was then forced to be her maid for the remainder of the dream, until her sheer rage allowed her forcefully leave the dream.

The following day, Saten told Mikoto about how the cards could be used for sleep learning. After Saten left, Mikoto met Hokaze again (though she did not tell her how she found the dream) and was invited to tea. On arriving, she found Shokuhou also there, displeasing both of them. Hearing Hokaze mention Indian Poker, Shokuhou told the two not to go any further with it. They then overheard Aogami Pierce, going by the Dream Ranker name BLAU, distributing erotic dream cards to other boys for free. After hearing about cards that involved them, the two Level 5s teamed up to destroy the cards, erasing electronic evidence and memories.

During Shirai Kuroko's cooperation with Miyama Shaei, a young girl used knowledge obtained from Indian Poker to make a chemical which she thought would keep cherry blossom trees in bloom year-round, but ended up creating a highly flammable compound which caused a large fire in the park.

Several days later the tea party and shortly after the fire, Mikoto watched Saten's skillful use of a kendama toy, learned through Indian Poker, with Saten looking to get a pen twirling one next. Shortly afterwards, she encountered a man who had set up a makeshift stand for trading and selling cards. Kinuhata Saiai was also present as the card trader's customer, looking for a story dream rather than a skill one. Mikoto did not seem to recognize her, and Kinuhata was off-duty and did not want to engage in unnecessary business. Still apprehensive after her previous experiences with Indian Poker, Mikoto kept her sentiments until the trader brought out his only S-rank card in possession, which he identified as the Bust Upper.

A short dispute between Mikoto and Kinuhata resulted in the trader's cards being scattered and mixed up, with the Bust Upper card lost among them. Buying all of the cards, the two teamed up to go through them all and find the information they wanted. Outbursts due to several dreams resulted in the girls being forced to use an outdoor location and subsequently a crow made off with the shiny Bust Upper card while they were sleeping, with the card eventually ending up in the hands of a girl who had been at the trader shortly before the dispute. Saten and Uiharu Kazari later saw the girl, now apparently with a larger bust.

Scientists also began making use of the cards to record their knowledge as a form of insurance. News that information on the Tweezers had apparently been leaked via the cards came to the attention of SCHOOL. During their investigation, Yobou Banka used his ability to skim the contents of a card in a vault and copy them to his own blank one, while a team attempted to abduct Saten, who had previously posted about obtaining a card from 'someone who could use chopsticks to grab even the smallest things'. Frenda Seivelun's intervention to save her led to SCHOOL's sniper Yumiya Rakko being dispatched and a battle between the two which ended in the latter's defeat. SCHOOL ultimately managed to obtain information on where the Tweezers would soon be used, under a week before the events of October 9th.

The proliferation of Indian Poker led to information previously restricted to School Garden leaking outside, with the nature of the card's production complicating the schools' efforts to prevent information leaks. After toys used to make the card dispenser were recalled by their manufacturers, likely under pressure from School Garden, an alternative design using different toys was uploaded. Judgment and Anti-Skill attempted to find the uploader without success.

Around the same time, Keitz Nokleben had identified Kuriba Ryouko as Indian Poker's creator for Shokuhou Misaki, who had recognized the theory behind the cards and intended to crush the one who had spread them. Learning of the experiment she was involved in, Shokuhou asked Mikoto for assistance, after teasing her about the previous incident, having read the trader's mind. The two made contact with Kuriba shortly after her doppelganger had escaped, two months before the point where Kuriba calculated she would get a solution. The ensuing events led to the doppelganger's termination, ending the problem the cards were meant to help solve.

Jailbreaker Arc
Following the resolution of the problem faced by its creator and with the card supply cut off, Indian Poker started to die off. Saten managed to buy a card for a youth Olympics level running long jump right at the end, and hoped to use the skill in the Jailbreak Trial, but never got the chance to do so.

Trivia

 * This concept is similar to the Level Upper in that it was created and spread throughout Academy City, becoming a trend, in order for its creator to resolve a certain problem they are unable to on their own.