Keno is similar to state lottery: you pick several numbers on a ticket, and hope to match the numbers drawn from the ping-pong ball machine. It’s also similar to the state lottery in that the odds are very bad. Keno in the casino has the highest edge of any game in the casino - 25% or more.
If you’re playing online the odds are much better. For example, the Pick 13 at Captain Cooks Casino offers a return of 96.54%. The pace of online keno is much faster, so you could still wind up losing more money by playing online even though the odds are better, because you’re placing so many more bets.
Many gambling authors will tell you to never play Keno because the edge is so high. In The New Gambler’s Bible, Arthur Reber says, “I wouldn’t play it with Monopoly money, and I hope you never will.” While Rebers has a point, if you’re only playing a few times for the thrill of a chance at a big win, losing a few bucks isn’t going to kill you. All educated people go into the casino with the understanding that they’re going to lose some money, so what’s the crime if you limit your Keno play to what you can afford to lose and you fully understand that the odds are bad? So long as you are aware of the odds, you play with them in mind, and you don’t bet more than you can afford, you’re in the clear.