The Talmud states that professional gamblers are among the four types of people who are deemed ineligible to serve as witnesses or judges (in addition to usurers, pigeon trainers and those who trade in the produce of the Sabbatical year). The rabbis explain that the gambler is disqualified because gamblers “are not concerned with the general welfare,” meaning that they do not contribute to a stable society (Talmud Sanhedrin 24b).
Understandably, both witnesses and judges must be above suspicion of transgression. Although the Torah does not outright prohibit gambling, the sages equated it to thievery, “Since no one knows beforehand whether one would gain or lose, neither fully consents to transfer possession to the other” (Talmud Eiruvin 82a). One could argue that this mindset applies even when two people bet against each other. But, it applies specifically to games of chance (racing, card games, dice, etc.) since the one who controls the game usually lures the players in with false hopes of winning riches.
The question is often asked whether participation in such games of chance like a raffle or the lottery are considered “gambling” according to halacha (Jewish law). In most instances, it is not considered problematic because the money is given in advance of the drawing and the players, in essence, accept the loss of that money at that time. Therefore, raffles and lotteries are permitted (particularly as the funds often go to benefit the community). However, it should be noted that the organizers of a lottery or raffle must make certain that the drawing is run honestly and fairly (all purchased tickets are included in the raffle and that unpurchased tickets are not eligible, etc.).
*Please note that the rabbis concluded that the rule applies only to professional gamblers and not casual gamblers.
Note: As there are different opinions as to what constitutes gambling, and what is or is not permitted, it is best to consult a rabbi. It is important to always remember that gambling, even those games that are permitted such as lotteries and raffles, can lead to addictive behavior.