Is it permitted to play cards for money at a casino? Furthermore, is one permitted to work at a casino in a corporate level position?
ב"ה Shalom I have to divide your question into three parts. 1. May one play cards for money? 2. May one play cards at a casino? 3. Is one allowed to have his livelihood come from actions of gambling? In regard to the first question, it is a question of the halachic attitude to the act of gambling. According to the Rav Yosef Karo in the Shulchan Aruch, gambling is considered "gezel" =stealing by Rabbinic definition, since the person who placed his money didn’t really intend to have the person take it. This is the Halacha for sefardim, even in a case if gambling with gentiles. though not because of "gezel" but because he occupies himself with useless things which have no contribution to the welfare of mankind. However, according the Rema, the act of gambling in itself is not considered gezel, and someone who has income from other sources may do so since through his other source of income he is doing something useful. (שו"ע חו"מ סי' שע, יביע אומר חו"מ ח"ז סי' ו) 2. Going to a casino is placing oneself in a culture which is foreign to Judaism. In the 14th century Rabbi Yitzchak Bar Sheshet, known as the Rivash, had already said that although according to some there is no issue of stealing in gambling ,nonetheless "dealing in gambling it is a most inappropriate thing, it is despicable and abominable and has caused many casualties in its path.". (שו"ת ריב"ש תלב 3.As we have seen in #2 gambling is far from the Jewish ideal and therefore I would not recommend working for a casino. However, if this is a practical question and not a theoretical one I would take the question to a Rabbi who knows you personally who can consider all factors involved. all the best