Re: Do you play the lottery?
If you are poor, playing the lottery makes sense. That $1 you spend will not change your life. The payoff will.
If you are a multi-millionaire, it's a waste. A jackpot will not change your life.
On "average" you lose about 70% of each dollar you put into the lotto, so it seems that playing is not a rational decision. But it can be...based upon the above (which some really smart people modeled mathematically and called "utility theory").
My wife play a buck or two when we go grocery shopping. I don't discourage her.
Myself, I play the financial markets. Better odds, but not necesarily more rational.