If gambling is your job I think you would end up paying taxes on your winnings, and gambling is certainly taxable in the United States, for instance. What is wrong with bluffing? When everyone knows that bluffing may be involved, it makes it part of a systematic attempt of winning a competition which adds interest to it for the participants. The fact that it is often a rather private activity does not make it problematic as such, and surely those who enjoy poker get both enjoyment and mental stimulation from considering the games of others as they are observed or reported to them. There is then perhaps more to say in favor of poker than your question suggests.
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Is it immoral to play poker (a game that inherently involves bluffing) full time to make a living even if it is more profitable for someone than a traditional job? Even if we consider it a sport akin to tennis or golf, it does not create economic value in the sense that's it's usually not being broadcast and there are no spectators or advertising. Players do not contribute to the tax base and social insurance; money is just being passed around from person to person.