Keno is a
lottery
A lottery is a form of gambling that involves the drawing of numbers at random for a prize. Some governments outlaw lotteries, while others endorse it to the extent of organizing a national or state lottery. It is common to find some degree of ...
-like gambling game often played at modern
casino
A casino is a facility for certain types of gambling. Casinos are often built near or combined with hotels, resorts, restaurants, retail shopping, cruise ships, and other tourist attractions. Some casinos are also known for hosting live entertai ...
s, and also offered as a game in some lotteries.
Players wager by choosing numbers ranging from 1 through (usually) 80. After all players make their wagers, 20 numbers (some variants draw fewer numbers) are drawn at random, either with a ball machine similar to ones used for lotteries and
bingo
Bingo or B-I-N-G-O may refer to:
Arts and entertainment Gaming
* Bingo, a game using a printed card of numbers
** Bingo (British version), a game using a printed card of 15 numbers on three lines; most commonly played in the UK and Ireland
** Bi ...
, or with a
random number generator
Random number generation is a process by which, often by means of a random number generator (RNG), a sequence of numbers or symbols that cannot be reasonably predicted better than by random chance is generated. This means that the particular out ...
.
Each casino sets its own series of payouts, called "paytables". The player is paid based on how many numbers were chosen (either player selection, or the terminal picking the numbers), the number of matches out of those chosen, and the wager.
There are a wide variety of keno paytables depending on the casino, usually with a larger "
house edge
Games available in most casinos are commonly called casino games. In a casino game, the players gamble cash or casino chips on various possible random outcomes or combinations of outcomes. Casino games are also available in online casinos, whe ...
" than other games, ranging from less than 4 percent to over 35 percent
in online play, and 20-40% in in-person casinos. By way of comparison, the typical house edge for non-slot casino games is under 5%.
History
The word "keno" has
French or
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
roots (Fr. ''quine'' "five winning numbers", L. ''quini'' "five each"), but by all accounts the game originated in China. Legend has it that the invention of the game saved an ancient city in time of war, and its widespread popularity helped raise funds to build the
Great Wall of China
The Great Wall of China (, literally "ten thousand ''li'' wall") is a series of fortifications that were built across the historical northern borders of ancient Chinese states and Imperial China as protection against various nomadic grou ...
. In modern China, the idea of using
lotteries
A lottery is a form of gambling that involves the drawing of numbers at random for a prize. Some governments outlaw lotteries, while others endorse it to the extent of organizing a national or state lottery. It is common to find some degree of ...
to fund a public institution was not accepted before the late 19th century.
Chinese lottery is not documented before 1847 when the Portuguese government of
Macao
Macau or Macao (; ; ; ), officially the Macao Special Administrative Region of the People's Republic of China (MSAR), is a city and special administrative region of China in the western Pearl River Delta by the South China Sea. With a pop ...
decided to grant a licence to lottery operators. According to some, results of keno games in great cities were sent to outlying villages and hamlets by
carrier pigeon
The homing pigeon, also called the mail pigeon or messenger pigeon, is a variety of domestic pigeons (''Columba livia domestica'') derived from the wild rock dove, selectively bred for its ability to find its way home over extremely long distan ...
s, resulting in its Chinese name 白鸽票 ''báigē piào'', with the literal reading "white dove tickets" in Mandarin, but in Southern varieties of Chinese spoken in
Guangdong
Guangdong (, ), alternatively romanized as Canton or Kwangtung, is a coastal province in South China on the north shore of the South China Sea. The capital of the province is Guangzhou. With a population of 126.01 million (as of 2020) ...
simply meaning "pigeon tickets", and pronounced ''baak
6-gaap
3-piu
3'' in
Cantonese
Cantonese ( zh, t=廣東話, s=广东话, first=t, cy=Gwóngdūng wá) is a language within the Chinese (Sinitic) branch of the Sino-Tibetan languages originating from the city of Guangzhou (historically known as Canton) and its surrounding are ...
(on which the Western spelling 'pak-ah-pu' / '
pakapoo
Pakapoo (; sometimes spelt pak-ah-pu) is a Chinese lottery game popular in Oceania in the 19th century, including on the Victorian Goldfields.
A pakapoo ticket is bought which contains rows of characters from the ''Thousand Character Classic'', ...
' was based).
The Chinese played the game using sheets printed with
Chinese characters
Chinese characters () are logograms developed for the writing of Chinese. In addition, they have been adapted to write other East Asian languages, and remain a key component of the Japanese writing system where they are known as ''kanji' ...
, often the first 80 characters of the ''
Thousand Character Classic
The ''Thousand Character Classic'' (), also known as the ''Thousand Character Text'', is a Chinese poem that has been used as a primer for teaching Chinese characters to children from the sixth century onward. It contains exactly one thousand c ...
'', from which the winning characters were selected.
[Melanie Yap, Dianne Leong Man. ''Colour, confusion and concessions'', pp.240-241.] Eventually, Chinese immigrants introduced keno to the West when they sailed across the Pacific Ocean to work on construction of the
First transcontinental railroad
North America's first transcontinental railroad (known originally as the "Pacific Railroad" and later as the " Overland Route") was a continuous railroad line constructed between 1863 and 1869 that connected the existing eastern U.S. rail netwo ...
in the 19th century, where the name was Westernized into boc hop bu
and puck-apu.
By 1866 it had already become a widely popular gambling game in Houston, Texas, under the name 'Keno'.
Probabilities
Keno payouts are based on how many numbers the player chooses and how many of those numbers are "hit", multiplied by the proportion of the player's original wager to the "base rate" of the paytable. Typically, the more numbers a player chooses and the more numbers hit, the greater the payout, although some paytables pay for hitting a lesser number of spots. For example, it is not uncommon to see casinos paying $500 or even $1,000 for a “catch” of 0 out of 20 on a 20 spot ticket with a $5.00 wager. Payouts vary widely by casino. Most casinos allow paytable wagers of 1 through 20 numbers, but some limit the choice to only 1 through 10, 12 and 15 numbers, or "spots" as keno aficionados call the numbers selected.
The
probability
Probability is the branch of mathematics concerning numerical descriptions of how likely an Event (probability theory), event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and ...
of a player hitting all 20 numbers on a 20 spot ticket is approximately 1 in 3.5
quintillion
Two naming scales for large numbers have been used in English and other European languages since the early modern era: the long and short scales. Most English variants use the short scale today, but the long scale remains dominant in many non-E ...
(1 in 3,535,316,142,212,174,320).
Probabilities in keno
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Even though it is highly improbable to hit all 20 numbers on a 20 spot ticket, the same player would typically also get paid for hitting “catches” 0, 1, 2, 3, and 7 through 19 out of 20, often with the 17 through 19 catches paying the same as the solid 20 hit. Some of the other paying "catches" on a 20 spot ticket or any other ticket with high "solid catch" odds are in reality very possible to hit:
Probabilities change significantly based on the number of spots and numbers that are picked on each ticket.
References
{{Gambling
Bingo
Lotteries
Gambling games