Gambling and lotteries

I read somewhere that while gambling is legal in Nevada (there were even slot machines at the gate in the airport), lotteries are illegal. This is misleading, though, since there's a game called Keno available in every casino we saw -- and even in some restaurants. Keno, which has the highest house advantage (see below) of any game in Vegas, is simply a fancy version of Lotto 6/49 - you get a card with numbers, pick a bunch of them, turn your ticket in, then a computer picks a bunch of random numbers and depending on how many numbers you got right, you win varying amounts of money. There are lots of different ways to win, but it's essentially a lottery.

The "house advantage" is the amount you can expect to lose at a particular game over a long period of time. For example, Keno has a house advantage of something like 30%, while slots are under 10% and poker and blackjack are under 5%. Roulette is pretty high as well, but I don't remember the number. Basically, the more skill you require, the less of a house advantage. My problem with gambling is that I get bored at slots because there is no skill involved whatsoever, but games like blackjack or poker require more skill than I have (to do anything other than lose consistently), so I'm outta luck. I did have fun playing video blackjack though, and had some luck the first night. I would like to learn more about blackjack though, and maybe next time I'm in a casino, I'll have the confidence to actually sit at a table with a real dealer!

One thing struck me as funny while gambling in Vegas -- the number of people who are frighteningly uninformed on games of chance. People who won't play a slot machine because it paid off recently - or try to play machines that have not paid off recently, figuring they have a better chance of winning there. The funniest thing was the big video board next to each roulette table, listing the previous 20 numbers that came up -- like this gives you any useful information whatsoever. One board I saw showed that four of the previous seven spins had been 1. Question: does this tell people to bet on 1 because it's coming up a lot, or don't bet on 1 because it's already come up more often than the "law of averages" allows? Answer: It tells you nothing. On a wheel with both 0 and 00, the probability of getting 1 on the next spin is exactly 1/38, regardless of whether 1 has come up recently or not. I wonder how much money casinos make because people can't seem to figure that out?