If you've ever heard anyone say that the lottery is a tax on stupidity in the general populace, then you won't be surprised to learn that most experienced gamblers think of keno as a tax on stupidity in the casino.
Regrettably, keno wagers concede more of an edge to the house than just about any other form of betting in a casino. The house edge on keno can be well over 30%, which is absolutely terrible when compared to other casino offerings (most of which surrender an edge of only 1% to 10% even when played by unskilled gamblers).
Is Keno Popular?
Even if you're the world's worst blackjack player (the kind of guy who gets dealt a natural 21 and asks for a hit), you would probably have a better chance of leaving the casino as a winner if you stuck with blackjack than if you switched to keno.
Nevertheless, keno remains popular (especially with casual casino goers) for the same reason that lotteries remain popular with the general public. It's enticing to think of placing a single small wager, picking some numbers, and collecting a gigantic payout simply for guessing right.
In fact, if you play the lottery every day mainly for the fun of anticipating what it would be like to win (and not because you have any real expectation of winning), then keno should be a lot of fun for you to play in the casino because you can probably cram the equivalent of a week and a half's worth of daily lottery tickets into a single hour of playing keno (each round of which will take about 5 minutes).
How Does Keno Work?
Every game of keno concludes in the same way--with 20 of the numbers from 1 through 80 being selected (usually by a computer or a machine blowing numbered balls out of a tube). The challenge for the players (as with ordinary lotteries) is to pick the winning numbers in advance.
Players make their selections by acquiring a keno card (which will usually present the numbers in 8 rows of 10 numbers each) and marking those cards to indicate the numbers they expect to come up (often by drawing an S or an X over the numbers of their choice).
Players then turn their cards over to a keno worker, who transfers the numbers from the keno card to an electronically generated receipt. (As with most state lotteries, players who don't care to choose their own numbers can usually ask for a random ticket, which will choose numbers for them. Since keno is random, your odds of winning neither increase nor decrease when you decide to let a computer pick your numbers.)
Don't worry. No one expects you to predict all 20 numbers. In fact, the odds of choosing the exact 20 winning numbers at the end of a keno game are so remote (a little worse that 1 in 3 and a half quintillion) that most casinos don't even have a pay scale for correctly predicting all 20. That's good news for the world economy because a quintillion is a billion billions. If casinos paid true odds on keno, then a player who guessed all 20 numbers correctly on a $1 keno ticket would be entitled to $3.5 quintillion. Paying the player wouldn't just bankrupt Las Vegas; it would require our planet to apply for a loan from the Inter-Galactic Federation.
Since 20 out of 80 numbers will be selected at the end of the game, you have a 1 in 4 chance of being right if you select just 1 number on your keno card. If the casinos paid fairly, you would win $4 on a $1 wager (that's your initial bet + $3 profit). Since you're only going to be paid $3 for winning (your initial bet + $2 profit), you can see that the longer you play keno, the more money you are likely to lose.
Although the pay scales in keno vary from one casino to the next, the payouts are generally determined according to a risk-reward ratio that makes some kind of sense (even if it is horribly lopsided in favor of the casino). If you pick just one number on your card and it is one of the 20 numbers drawn at the end of the game, then you had 1 "catch" out of 1 attempt, and you should expect something like a 3-for-1 payout. If you picked 2 numbers and they both came up (for 2 catches out of 2 selections), then you could expect something like a 12-for-1 payout. If you choose 10 numbers and catch 6 of them, you'll win more than the guy who picked 10 and only caught 5.
This is why people who play keno should stay away from all the fancy variations allowed by the casinos (such as way bets, king bets, and combinations). The only good thing about keno is that each game happens far more slowly than a hand of blackjack or a round of slot machine play. With keno, what the house gains in edge, it loses in efficiency (where efficiency is measured in the amount of dollars per second that leave your wallet). The fancy variations allow you to make multiple wagers at once, so a single keno card can cost as much as you want to spend on it. If you insist on playing keno, do your wallet a favor by keeping it as simple and as slow as possible.