Keno is a lottery-like or bingo-like gambling game often played at modern casinos, and is also offered as a game in some state lotteries. A traditional live casino keno game uses a circular glass enclosure called a "bubble" containing 80 ping pong-like balls which determine the balldraw result. Each ball is imprinted with a number 1 through 80. During the balldraw, a blower pushes air into the bubble and mixes the balls. A "caller" presses a lever opening a tube, where the balls lift one at a time into a "V" shaped tube called the "rabbit ears". The caller and a "verifier" record each of 20 balls drawn, and the computerized keno system calculates all wagers based on the numbers drawn.
Players wager by marking an "X" over the "spot" choices on a blank keno ticket form with 80 numbered selection boxes (1 to 80). After all players successfully place their wagers, the casino draws 20 balls (numbers) at random. Some casinos automatically call the balldraw at preset timed intervals regardless of whether or not players are waiting to place a wager.
Each casino sets its own series of pay scale choices called "paytables". The player is paid based on how many numbers drawn match the numbers selected on the ticket and according to the paytable selected with regard to the wager amount. Players will find a wide variation of keno paytables from casino to casino and a large deviation in the house edge set for each of those paytables. Additionally, each casino typically offers many different paytables and specialty keno bets for customers to choose from, each with its own unique house edge. No two casinos' keno paytables are identical. There are several Reno and Las Vegas casinos offering as many as 20 or 30 different paytables from which the player can choose.[citation needed]
The house edge ranges from less than 4% to 66%. The typical house edge for non-slot casino games is between 0% and 5%.
Keno Odds: Keno payouts are based on how many numbers the player choses and how many 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 from casino to casino. Most casinos allow paytable wagers of between 1 and 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 of a player hitting all 20 numbers on a 20 spot ticket is approximately 1 in 3.5 quintillion (1 in 3,535,316,142,212,180,000 to be exact). If every person now alive played one keno game every single second of their lives, there would be about one solid 20 jackpot-winning ticket to date. If all these possible keno tickets were laid end to end, they would span the Milky Way galaxy -- and only one of them would be a winner. Even though it is virtually impossible 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:
20 Spots 0 Hits: 1 In 843.380 Or 0.11857057% 20 Spots 1 Hits: 1 In 86.446 Or 1.15678605% 20 Spots 2 Hits: 1 In 20.115 Or 4.97142576% 20 Spots 3 Hits: 1 In 8.009 Or 12.48637168% 20 Spots 4 Hits: 1 In 4.877 Or 20.50318987% 20 Spots 5 Hits: 1 In 4.287 Or 23.32807380% 20 Spots 6 Hits: 1 In 5.258 Or 19.01745147% 20 Spots 7 Hits: 1 In 8.826 Or 11.32954556% 20 Spots 8 Hits: 1 In 20.055 Or 4.98618021% 20 Spots 9 Hits: 1 In 61.420 Or 1.62814048% 20 Spots 10 Hits: 1 In 253.801 Or 0.39401000% 20 Spots 11 Hits: 1 In 1423.822 Or 0.07023351% 20 Spots 12 Hits: 1 In 10968.701 Or 0.00911685% 20 Spots 13 Hits: 1 In 118084.920 Or 0.00084685% 20 Spots 14 Hits: 1 In 1821881.628 Or 0.00005489% 20 Spots 15 Hits: 1 In 41751453.986 Or 0.00000240% 20 Spots 16 Hits: 1 In 1496372110.872 Or 0.00000007% 20 Spots 17 Hits: 1 In 90624035964.712 Or 0.00000000% 20 Spots 18 Hits: 1 In 10512388171906.553 Or 0.00000000% 20 Spots 19 Hits: 1 In 2946096785176811.500 Or 0.00000000% 20 Spots 20 Hits: 1 In 3535316142212173800.000 Or 0.00000000%
In modern keno, players are offered the option of playing multi-race keno, which books a keno ticket for a number of sequential keno races up to 1000. The races must always start on the next sequential race to be drawn. When the sequence of wagered games is finished, the player is able to redeem any winnings within the time constraints specified in the casino's rules booklet.
After picking wager numbers, recording them at the keno booth and obtaining the “keno ticket” (official wager receipt), the player watches the balldraw in progress as the spot (number) selections light either on an electronic keno board or on a video monitor. Keno displays are typically found throughout the casino and sometimes even appear on a television channel in casino hotel rooms. Nowadays, after playing keno at a participating casino, keno players can even take their multi-race keno tickets out of the casino to watch the live balldraw or check historical draw results at [www.kenousa.com] anywhere there is a computer and an Internet connection.
In the past, a winning ticket needed to be taken to the keno booth for collection immediately after the race results were posted, and drawings usually took place approximately every five or six minutes. In days of old, if the player tried to redeem a winning ticket after the next sequential race began, the ticket was declared expired and no money was paid out even if it won. Nowadays most casinos set their "late pay" window to accommodate the player, however there is great variation in the published late pay window from casino to casino. Tickets played for 21 races or more typically offer one year for collection in most major gaming jurisdictions. Tickets played for under 21 races have a great disparity of late pay rules from casino to casino. Keno players are wise to read the rules published in the host casino's keno paybook to determine when a keno pay will expire and become uncollectible. Gaming authorities require that all pay scales and keno rules be posted in a prominent location in keno areas.
An embellishment of keno is “way” keno or “combination” keno. When playing a way or combination keno ticket, the player circles groups of numbers within the spots marked and specifies combinations of groups which combine together to make different "ways". For example, if a player marks four numbers, and circles two groups of two spots each, a combination ticket could be made in which the gambler plays one 4 spot and two 2 spots (2-2). If an additional group of two were added and circled, the player could play ways 1/6, 3/4 and 3/2 (2-2-2), which at $1.00 per way would create a $7.00 per race wager. Serious keno players use great imagination on keno tickets to make complex combinations of groups and ways with varying numbers of spots in each group. There is literally no limit to the way players can circle spots of like or a differing number of spots and in the resulting “ways” they can choose to play on a keno ticket.
As alternatives to traditional paytables which offer the selection of 1 to 20 spots, a number of special paytables are available and are often offered as a wager choice. For example, with the Top/Bottom paytable the keno player does not select any spots. Rather, the player is betting that the balldraw top 40 and bottom 40 ball distribution will be uneven. Top/Bottom typically begins paying on a 7/13 or 13/7 ball distribution between the top half (1 to 40) and bottom half (41 to 80) of the keno grid and the payouts increase with each higher balldraw distribution disparity. The same principle is applied for the Left/Right or Odd/Even paytables. Other specialty paytables are Top Only, Bottom Only, Left Only, Right Only, Odd Only, Even Only, Parlay, Exacta, Edge, Square, or eXtra Million, which is proprietary to XpertX Keno Systems. However the traditional 1 though 20 spot pick is by far the most popular variety of live keno.