KENO  

The game of keno uses 80 balls that are numbered 1 thru 80. 

The player will mark a ticket selecting from 2 to 15 numbers. You place your bet by marking a keno ticket, a piece of paper with the numbers 1 thru 80 printed on it. Keno tickets are located at tables throughout the casino but are most readily found in the casino's keno lounge: a room or area with chairs to sit and write. Usually crayons are provided for marking the ticket. The payoffs and odds of winning depend on the number of spots you mark and how many balls you "catch" (match your numbers).

In every game, the casino (house) will draw 20 balls at random and displays their numbers on screens (called keno boards) located throughout the casino. 

The Basics: 

Before you go marking a ticket, make sure you know the house rules. If you go to the Keno lounge, you will find a copy of the house's keno brochure. This will tell you what the standard bets and payouts are this year.

MAKE SURE YOU KNOW IF YOU NEED TO CASH YOUR TICKET IMMEDIATELY FOLLOWING THE GAME. MANY CASINO'S STILL REQUIRE THIS UNLESS YOU PLAY 21 GAMES.

Here is what an extract from a keno brochure might look like.

                    Play 6 numbers

          Catch    play $1   play $2   play $5

            3         $ 1      $  2       $  5
            4         $ 8      $ 16       $ 40
            5        $ 50     $ 100      $ 250
            6      $ 1500    $ 3000     $ 7500

The top line, "Play 6 numbers" means this section of the brochure pertains to the payoffs you would be paid if you marked 6 numbers. "Numbers" are also referred to as "spots". When  you play 6 numbers,  you are said to be "playing a 6-spot". You can play more or fewer than 6 spots but for now let's stick with 6.

The term catch refers to how many of your (6 in this case) chosen numbers match what the house draws. "Play $1" means you can bet $1 on your ticket. As the table shows, you can bet more than $1 if you're in a real hurry to lose your money. There absolutely no statistical advantage to betting more than the minimum wager. Payoffs are simply scaled by the amount you bet. 

MAKE SURE YOU KNOW THE HOUSE LIMIT. DO NOT PLACE A WAGER THAT WILL EXCEED THE AGGREGATE LIMIT OF THE GAME. WHY BET $5.00 ON A 10 SPOT IF THE MAXIMUM PAYOUT IS $50,000 AND YOUR BET SHOULD PAY $100,000.

As the payoff table shows, if you play 6 numbers and catch all 6, a $1 ticket will return $1500.

If you "only" catch 5 numbers the payoff is substantially less, and so on, down to a $1 payoff for catching any 3 of the 6 you selected. If you catch fewer than 3, your ticket is worthless. Of course this is just an example of a payoff schedule; that's why you need to check the keno brochure to see what payoff scale the casino is using.

You can mark a ticket with anywhere from 1 to 15 (more in some places) numbers. The more numbers you mark the more you have to catch to win. The payoffs are set such that in dollar terms the house percentage is pretty much the same regardless of how many numbers you mark. You will find some variety in the minimum payoff so you can to some extent choose if you want many small wins or fewer, larger wins.

Be aware of special bets or promotions. Sometimes when you mark a lot of numbers the casino pays off if you catch 0 numbers. This would be shown in the keno brochure.

A basic example:

You play a $1 "6-spot". Pick a blank keno ticket, grab a crayon and cross out your 6 choices with a plain X. On the right of the ticket write "$1" and beneath that the number "6" to indicate you are playing a 6-spot. This is used for cross-checking by the dealer, and it helps if you are playing combination tickets.

Once you have marked your ticket, bring it to a dealer (also called a writer or cashier) at the front of the keno lounge.  Hand your ticket and money to the dealer. He or she will make a copy of your ticket and give you the copy, retaining the original. Verify your copy before leaving the window because in case of a big win the house will verify that you actually marked those numbers on the original ticket you gave the dealer. They index and save the original tickets and will hunt through them if you catch a big winner. This helps prevent fraud.

Once all bets are placed, the dealer will announce that the game (Game Number XXX) is closed. The dealer then calls out the numbers and throws the switch that causes that number to light on the keno board. After the 20th and last number is chosen the dealers return to their stations. U.S. tax law requires winning tickets to be cashed immediately after the game however many casino's are starting to allow tickets to be cashed within 24 hours of the drawing unless the player bets on 21 games or more in which case the player has up to 1 year to claim their winnings..

If you want to play the same ticket for the next game, you don't need to mark up another blank ticket. Just hand the losing ticket to the dealer along with the money and they will make you another copy. If you cash in a ticket that pays off, the dealer will probably ask "Want to play it again?" If you answer yes you'll get back a new ticket and your winnings, less the cost of the ticket for the next game.

How do I calculate the odds of winning at keno?

My simple answer is don't bother ... just accept the fact that it is a bad bet (usually a 25%+ house edge) and have fun. The best break down of odds in Keno I have found is at: 

http://www.conjelco.com/faq/keno-odds.html .